following document has been slightly modified (primarily by the omission of
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The original (large) PDF file can be found here.
ENDANGERED KARST INVERTEBRATES
Ruth A. Stanford
Literature citations for this document should read as follows:
U. S. Fish and Wildlife Service. 1994. Recovery Plan for
Endangered Karst Invertebrates in Travis and Williamson
Additional copies may be purchased from:
Fish and Wildlife Reference Service
The fee for the plan varies depending on the number of
pages of the plan.
The study of caves and karst in
process. Much of the information presented in this plan
was derived from research in progress. Besides William R.
Elliott, who prepared the initial draft of this plan,
contributors include James R. Reddell, George Veni, Mike
Warton, and Bill
provided significant comments to William Elliott in the
early development stages of this plan.
EXECUTIVE SUMARY OF THE RECOVERY PLAN OR ENDANGERED
KARST INVERTEBRATES IN TRAVIS AND
Species’ Status: All seven species (Texella reddelli, Texella reyesi,
Tartarocreagris texana, Neoleptoneta
myopica, Rhadine persephone,
Texamaurops reddelli, and Batrisodes texanus) are
endangered. They spend their entire lives underground and are endemic to
karst formations (caves, sinkholes, and other subterranean voids) in Travis
and Williamson counties,
Habitat Requirements and Limiting Factors: All tend to occur
in the dark zone of caves, but occasionally in deep twilight.
All prefer relative humidities near 100%, but some may be less
sensitive to drying than others. Presumably all are predators
upon small or immature arthropods, or, as in the case of the
ground beetle, possibly cave cricket eggs.
TABLE OF CONTENTS
Table of Contents
A. Objective and Criteria
B. Recovery Outline
C. Narrative Outline for Recovery Actions
III. Implementation Schedule
B. List of Commenters
C. Summary of Comments and USFWS Response
Table 1 – 3
Figure 1 - 11
I. INTRODUCTION AND BACKGROUND
[Appendix A contains a glossary of terms used in this
recovery plan. Terms defined in the glossary are indicated
by BOLD face type in the text.]
This recovery plan covers seven species of karst
invertebrates and their ecosystems. The seven species are:
Neoleptoneta myopica (Tooth Cave spider),
Five species (Texella reddelli, Tartarocreagris texana,
Neoleptoneta myopica, Rhadine persephone, and Texamaurops
reddelli) were listed as
(53 FR 36029). A refinement of the taxonomy has expanded
this group into seven distinct species (58 FR 43818)
Because Texella reyesi and Batrisodes texanus were
considered to be populations of Texella reddelli and
Texamaurops reddelli, respectively, at the time of listing,
they are also considered to be listed as endangered under
the Endangered Species Act (58.FR 43818).
Of the seven listed species, three are insects (one
ground beetle and two mold beetles) and four are arachnids
(one pseudoscorpion, one spider, and two harvestmen) . All
are troglobites, which spend their entire lives underground
and have small or absent eyes, elongated appendages, and
other adaptations to the subterranean environment.
Although troglobites must complete their life cycles
underground, they are dependent on moisture and nutrient
inputs from the surface. Troglobites typically inhabit the
dark zone of the cave where temperature and humidity are
relatively constant. Most are usually found under rocks.
All seven species appear to be predators and are found in
relatively small numbers. Each species may have a
different preferred microhabitat and may depend on certain
prey species for survival. Troglobites tend to be rare
and limited in distribution and are of special interest to
evolutionary biologists, ecologists, biogeographers, and
educators. Their limited distributions combined with low
reproductive rates, ecological specialization, and other
factors, make troglobites especially vulnerable to habitat
destruction, fire ant infestations, pollution, and other
A. Taxonomic and Legal Classification, and Description
Note on Common Names and Arthropod Systematics
Few invertebrates have common names. Common names are
often used for convenience sake and may become standardized
for well-known or commonly studied species. The common
names for the karst invertebrates included in this recovery
plan are given in this section (A) However, because there
are no official common names for these invertebrates,
because taxonomy is most clearly understood in terms of
scientific names, and because most biologists working with
these species refer to them by scientific name, we use
scientific names throughout this plan.
Scientific names are sometimes changed by scientists
according to the International Code of Zoological
Nomenclature. As taxonomists study certain groups, they
publish descriptions of new or previously unrecognized
species or assign known species to different groups. For
example, the spider Leptoneta myopica was reassigned to the
All of the listed species are members of the Phylum
Arthropoda. With some arthropods, it is important to
obtain mature male specimens for study. In many cases, as
in the mold beetles and harvestmen, species are identified
based on the structure of the male genitalia. These
structures are highly species-specific and believed to be
under genetic control. Often a first collection from a
cave contains only immature and female specimens. Other
species, such as the ground beetles, pseudoscorpions, and
several species of spiders (including Neoleptoneta
myopica), can be differentiated based on male or female
structures (such as the ovipositor), as long as an adult
specimen is obtained.
SPECIES 1 — Scientific name: Neoleptoneta myopica
(Gertsch), formerly Leptoneta myopica Gertsch
Taxonomic Classification: Class Arachnida
(arachnids), Order Araneae (spiders), Infraorder
Araneomorphae (true spiders),
Spiders and other arachnids are not insects. Unlike
insects, arachnids possess four pairs of legs,
pedipalps, and chelicerae, and lack antennae. Insects
have three pairs of legs, mandibles, and antennae.
Leptonetids are minute spiders with six eyes, commonly
found in caves and similar habitats. Some leptonetid
eyeless, but members of this family typically have
Original Description: Gertsch (1974)
Type Specimen: Male holotype,
Reddell. Female specimen described but not designated
as paratype. Type specimens are deposited in the
Other Taxonomic Literature: Brignoli (1972) erected
the genus Neoleptoneta for
spiders and reserved the genus Leptoneta for other
regions. In 1977, Brignoli formally removed Leptoneta
myopica to Neoleptoneta. The validity of Neoleptoneta
was further supported by Platnick (1986). This
recovery plan follows these two authorities in using
the name Neoleptoneta.
Selected characteristics: A small, whitish, longlegged
troglobitic spider with six obsolescent eyes.
Eyes medium sized, without dark pigment; front eye row
moderately recurved; eyes subcontiguous and subequal
in size; posterior eyes subcontiguous, set back from
anterior lateral eyes. First leg in both sexes 6.1
times as long as carapace. Body length 1.6 mm,
carapace 0.7 mm long and 0.5 mm wide, abdomen 0.9 mm
long and 0.5 mm wide. Tibia of male palpus with thin
retrolateral process set with curved spine.
Intraspecific Variation: Not known.
Distinctiveness: Neoleptoneta myopica is related to
several other troglobites in the Balcones Fault Zone
County; N. concinna from a cave and a mine in Travis
County; N. devia from one
N. microps from one cave
Geographically, the Neoleptoneta species closest to N.
myopica is N. devia
only 2.5 km from
Cave, the type locality. Neoleptoneta devia is dull
yellow with a whitish abdomen and the eyes enclose a
dusky field, whereas N. myopica is whitish and has
very reduced eyes that are not set in a dusky field.
Neoleptoneta devia and N. concinna, the other two
Gertsch (1974) did not discuss evolutionary
relationships among the six
that he described.
Recovery Priority: 2C. According to the 13. 5. Fish
and Wildlife Service’s (USFWS) criteria (48 FR 51985)
this indicates a species with a high degree of
threats, high potential for recovery, and in conflict
with construction or development projects or other
forms of economic activity.
SPECIES 2 — Scientific name: Tartarocreagris texana
(Muchmore), formerly Microcreagris texana Muchmore.
Taxonomic Classification: Class Arachnida (arachnids), Order Pseudoscorpiones (pseudoscorpions), Family Neobisiidae. Pseudoscorpions are quite distinct from scorpions in lacking a postabdomen (tail), stinger, and book lungs. Most pseudoscorpions are no more than a few mm long.
Original Description: Muchmore (1969).
Type Specimen: Female
Reddell. Deposited in
History. Male known from
Other Taxonomic Literature: Muchmore (1992)
reassigned Microcreagris texana to Tartarocreagris, a
genus described by Curcic (1984), based on the female
holotype of M. infernalis from Inner Space Cavern,
collected males of both species, it became clear that
M. texana also belonged in Tartarocreagris. Curcic
(1989) had previously reassigned N. texana to
Australinocreagris Curcic (1984), which is based on M.
that classification to be incorrect based on internal
male genitalia. Muchmore (1992) described a new
species of Tartarocreagris, T. comanche, from New
Comanche Trail Cave 1.8 km
and reassigned N. reddelli, from
County, to Tartarocreagris. In Muchmore (1992) , all
Tartarocreagris. The genus Microcreagris is no longer
believed to occur in the
of Tartarocreagris are
extremely limited in distribution. Three of the species occur within 4.9 km
of each other in the vicinity of the RM 2222 and RM 620 intersection on the
central Jollyville Plateau in Travis
Selected Characteristics: A large (female body length
4.1 mm), eyeless pseudoscorpion with attenuated
appendages. Carapace, chelicerae, and palps golden
brown, body and legs light tan. Carapace about 1/3
longer than broad. No eyes or eyespots present.
Chelicera about 2/3 as long as carapace, 1.95 times as
long as broad. Palps relatively long and slender;
femur 1.5 and chela 2.55 times as long as carapace.
Intraspecific Variation: Male very similar to female
in most respects — male body length 3.96 mm.
Distinctiveness: Tartarocreagris texana can be
distinguished from its closest relatives only by
microscopic inspection. Tartarocreagris comanche from
and relatively robust appendages, whereas the others
are eyeless and more slender. Among the species of
Tartarocreagris there are many minor differences in
tergal chaetotaxy and in the proportions of the palps.
Confirmation of the species may require dissection and
study of the female spermathecae or the male internal
Recovery Priority: 2C
SPECIES 3 — Scientific name: Texella reddelli
Goodnight and Goodnight
Classification: Class Arachnida (arachnids), Order Opiliones (opilionids, or
harvestmen) , Suborder Laniatores,
evolutionarily quite distinct
from spiders (Order Araneae) and are not properly referred to as “spiders”.
Phalangodid harvestmen are predaceous. Other North American genera are Banksula
Original Description: Goodnight and Goodnight (1967)
Type Specimen: Male holotype,
Deposited in the
Redescription by Thick and Briggs (1992) is based on
holotype, female paratopotype, and 14 other specimens
deposited in the
Darrell Thick collection, and Marie Goodnight collection.
Other Taxonomic Literature: Goodnight and Goodnight
(1942), Ubick and Briggs (1992). The genus Texella
was erected by Goodnight and Goodnight (1942) on the
basis of one troglomorphic individual, described as
Selected Characteristics: Body length 1.90-2.18 mm,
scute length 1.21-1.66 mm, leg II length 4.92-7.59 mm,
leg II/scute length 3.81-5.20 mm (N = 16). Color
orange. Body of medium rugosity. Eye mound broadly
conical, eyes well developed. Male (holotype) —
Postopercular process length 0.44; penis: ventral
plate prong with two dorsal, 10 lateral, and three
ventral setae; apical spine curved, apically pointed;
glans: basal knob slender; middle lobe present;
parastylar lobes claw-like; stylus spatulate, basal
fold present. Female (paratopotype) — Ovipositor
cuticle intricately folded; one pair of apical teeth
Intraspecific Variation: Juveniles are white to
yellowish-white (as in most Texella); adults are
orange. The tarsal count (number of tarsomeres) and
the leg-to-body-length ratio (leg II/scute length) may
vary from the south to north part of the species’
range, with the least troglomorphic (cave-adapted)
population being in Cave Y (south
River) and the most troglomorphic in Jester Estates
Cave (north of the
this species is not easily explainable in that it is
distributed on both sides of the
is a major barrier to other terrestrial troglobites.
Troglomorphy in this genus is marked by increased
leg/body ratio, greater number of tarsomeres,
depigmentation, reduction of protuberances, and loss
of retinas followed by loss of corneas.
Distinctiveness: Goodnight and Goodnight (1942)
described Texella mulaiki from
Ezell’s Cave), but in 1967 reported it from Cotterell
and material, they did not note that the distribution
patterns of the two species were incongruously mixed.
Apparently the identifications were based more on leg
length than other characters. Thick and Briggs (1992)
examined more specimens from more caves and epigean
sites and in their revision distinguished T. reddelli
from T. reyesi (below). They described 18 new species
and transferred one species from Sitalcina to Texella.
Sixteen of the 21 Texella species are cavernicoles and
five are troglobites. Fifteen of the species occur
along the Balcones Escarpment in
T. reddelli can be distinguished in the field
from its closest relative, T. reyesi by its shorter
legs, its well developed eyes (versus extremely small
or no eyes in T. reyesi), and its color, which is more
orange. The species is not “without eyes” as noted by
Goodnight and Goodnight but has “eye mound broadly
conical, eyes well developed” (Thick and Briggs 1992).
Such details can be seen with the naked eye or a hand
lens in the field. However, confirmation of the species must be made microscopically by a qualified systematist on a preserved, adult specimen.
In their redescription of the Texella species,
Thick and Briggs (1992) state that Texella reddelli
and Texella reyesi “are clearly very closely related
and, using the standards of genitalia distinctness
applied to other Texella species, may even be considered conspecific.” However, given that the two groups can be distinguished, and are considered separate in the taxonomic description, the USFWS follows Thick and Briggs and considers the two species separately.
Recovery Priority: 2C
SPECIES 4 — Scientific name: Texella reyesi Thick and
Taxonomic Classification: Class Arachnida (arachnids)
Order Opiliones (opilionids, or harvestmen), Suborder
Original Description: Ubick and Briggs (1992). This
paper describes 18 new species of Texella, with a
total of 21 species in three species groups in
species diversity (15 species) is along the Balcones
Type Specimen: Male holotype,
Cave. All specimens are deposited at the
Other Taxonomic Literature: Goodnight and Goodnight
(1942, 1967). The genus Texella was erected by
Goodnight and Goodnight (1942). In 1967 they
described Texella reddelli, which at that time
included some populations of Texella reyesi.
Selected Characteristics: A long-legged, blind, pale
orange harvestman. Body length 1.41-2.67 mm, scute
length 1.26-1.69 mm, leg II length 6.10-11.79 mm, leg
II/scute length 4.30-8.68 mm (N = 85). Body finely
rugose. Few small tubercles on eye mound; eye mound
broadly conical, retina absent, cornea variable (well
developed, reduced, or absent). Penis with ventral
plate prong round apically; two dorsal, 17 lateral,
and four ventral setae; apical spine bent, apically
pointed, length 0.05 mm. Glans with basal knob
narrowly conical; middle lobe long; parastylar lobes
claw-shaped. Stylus long, curved, ventrally carinate,
apically spatulate; basal fold well developed.
Intraspecific Variation: Juveniles are white to
yellowish-white. Adults are pale orange. Elliott
(unpublished data) has observed an adult with a pale
green abdomen in
County, and an adult with a yellowish abdomen in
Distinctiveness: Texella reyesi can be distinguished
from its closest relative T. reddelli by its longer
legs, its lack of retinas (versus well developed eyes
in Texella reddelli), and its color, which is pale
orange. Such differences can be seen with the naked
eye or a hand lens in the field. However, confirmation of the species must be made microscopically by a qualified systematist on a preserved adult.
Listed: Because Texella reyesi was considered to be
Texella reddelli before Ubick and Briggs’
redescription (1992) and five localities (Tooth,
McDonald, Weldon, Bone, and Root caves) of T. reyesi
were included with T. reddelli at the time T. reddelli
was listed as endangered on
36029), T. reyesi is considered to be listed as
endangered under the Endangered Species Act. The
USFWS has reviewed the taxonomic change (Ubick and
Briggs 1992) and other available information on this
species and determined it should remain listed as
endangered (58 FR 43818)
Recovery Priority: 2C
SPECIES 5 — Scientific name: Rhadine persephone Barr
Taxonomic Classification: Class Insecta (insects),
Order Coleoptera (beetles), Suborder Adephaga,
Carabidae (ground beetles), Tribe Agonini (agonines).
Many troglobitic ground beetles have evolved in
and other parts of the world. The genus Rhadine
contains more than 60 eyed and eyeless species in the
mostly in caves of the Balcones Escarpment of Texas
and are members of the subterranea species group, a
monophyletic assemblage. The subterranea group is
closely related to the perlevis group, which contains
eyed, troglophilic members found in caves of the
contains a “robust”, or heavy-bodied, subgroup, which
is generally found south of the
which includes R. persephone north of the river. A
“slender” subgroup, including R. subterranea, is
widely distributed on both sides of the river. At
least three different species pairs coexist in some
caves, consisting of a robust species and a slender
species in each case. In most situations the robust
species is more abundant. These data suggest that the
ranges of the various species may overlap broadly, but
that minimal niche overlap occurs between robust and
slender species, which allows the two species to
coexist in some caves.
Original Description: Barr (1974a)
Type Specimen: Holotype male,
Mitchell, T.C. Barr, Jr., and W.M. Andrews.
Selected Characteristics: A moderately robust and
convex beetle, more so than other species of the
subterranea group. Reddish-brown, head and pronotum
shining. Head half as wide as long, neck about 0.57-
0.59 of greatest head width. Eye rudiment larger than
in other species of subterranea group. Pronotum about
0.7 as wide as long, widest in apical three-eighths,
slightly wider than head. Antenna about 0.85 total
body length, attaining apical third of elytra when
laid back. Aedeagus very large for subterranea group,
1.24-1.31 mm long, elongate, feebly arcuate, basal
bulb slender and set off by slight constriction, keel
prominent, apex attenuate and slightly produced;
internal sac with proximal patch of numerous scales.
Body length 8.0 mm, head 2.17 mm long by 1.08 mm wide,
pronotum 1.80 mm long by 1.18 mm wide, elytra 4.46 mm
long by 2.29 mm wide, antenna 6.8 mm long. Fifty
paratypes and four specimens from
with length 7.2-8.7 mm, mean 7.8.
Intraspecific Variation: Not known.
Distinctiveness: Rhadine persephone is distinguished
from R. subterranea by its more robust build and its
shorter and wider pronotum (the most distinguishing
characteristic) . The two species are about the same
length. Tenerals (young adult beetles that have
recently emerged) of all Rhadine species are pale
yellow but soon darken to reddish brown. Other species that
can be confused with R. Persephone include R. austinica (southern
Recovery Priority: 2C
SPECIES 6 — Scientific name: Texamaurops reddelli
Barr and Steeves
Taxonomic Classification: Class Insecta (insects)
Order Coleoptera (beetles), Suborder Polyphaga,
Pselaphidae (mold beetles), Tribe Batrisini.
Pselaphids, or short-winged mold beetles, are a group
of small beetles found under stones and logs, in
rotting wood, moss, ant and termite nests, and caves.
The European and North American cave faunas include
many species. The genus Texamaurops was erected for
one species, T. reddelli,
Texamaurops remains a monotypic genus found only in a
Original Description: Barr and Steeves (1963)
Type Specimen: Female holotype,
James R. Reddell and David McKenzie. Deposited in the
a rock in the second room of the cave, about 10 m from
Other Taxonomic Literature: The first pselaphid
described from a
schneiderensis Park (1960), based on a single female
(1974b) classified a male pselaphid from Inner Space
Cavern as Texamaurops reddelli, but the specimen is
now recognized by
Selected Characteristics: A small, long-legged beetle
with short elytra leaving five abdominal tergites
exposed; metathoracic wings absent. Body length 2.72-
3.08 mm. Color reddish-brown, shiny; pubescent hairs
pale, moderately abundant and partially laid back;
general body surface sparsely and weakly dotted with
small pits. Ventral surface of head heavily
pubescent. Eyes absent, but represented by small
knobs with six vestigial eye facets. Antennae 11-
the holotype female from
having only two basal foveae (pits) on each elytron,
whereas the others have three equal foveae. All
others features appear to be similar.
Distinctiveness: Texamaurops reddelli can only be
distinguished from other pselaphid beetles by a
qualified systematist upon microscopic study. The
species is “superficially similar to Batrisodes
texanus by the greatly elongated antennae and legs, as
well as body size” (
definitively separated from Batrisodes texanus by its
ocular knobs and its lack of the pencil of setae on
the form of the aedeagus and antennal characters
Texamaurops is probably best considered a lineage
derived from Batrisodes that has lost the metatibial
pencil of setae.” In life Texamaurops reddelli is a
tiny, long-legged form that can be confused with other
species such as Tachys ferrugineus, which is an eyed,
short-legged, shiny, fast-moving carabid beetle with
full-length elytra; and Batrisodes uncicornis, an eyed
species occurring in many caves in
Other pselaphids, both blind and eyed, occur in caves
outside the range of this species (
Recovery Priority: lC. Indicates a monotypic genus
with a high degree of threats, high potential for
recovery, and in conflict with construction or
development projects or other forms of economic
activity (48 FR 51985)
SPECIES 7 — Scientific name: Batrisodes texanus
Taxonomic Classification: Class Insecta (insects),
Order Coleoptera (beetles), Suborder Polyphaga,
Pselaphidae (mold beetles), Tribe Batrisini. Mold
beetles are generally minute (about 2 or 3 mm long)
rounded beetles with short elytra (wing covers), which
expose the posterior half of the abdomen.
Type Specimen: Male holotype from Inner Space Cavern,
Space Cavern and Off
(deposited in Donald S. Chandler collection) and
first collected on
Other Taxonomic Literature: Barr (1974b) classified
a male pselaphid from Inner Space Cavern as
Texamaurops reddelli, but the specimen is now
Selected Characteristics: A small, long-legged beetle
with short elytra leaving five abdominal tergites
exposed; metathoracic wings absent. Body length 2.60-
2.88 mm. Male with vague groove across the head
anterior to antennal bases. Sides of head smoothly
curved and flat with a few granules present where eyes
Intraspecific Variation: In females, the transverse
impression anterior to the antennal bases is absent,
and the tenth antennal segment is barely wider and
longer than the ninth. In males the tenth is twice as
wide as the ninth. No geographical variation has been
Distinctiveness: Batrisodes texanus can only be
distinguished from other pselaphid beetles by a
qualified systematist upon microscopic study. The
species can be definitively separated from Texamaurops
reddelli by its lack of ocular knobs and the presence
of a pencil of setae on the metatibia. In life the
beetle is a tiny, long-legged form that can be
confused with other species such as Tachys
ferrugineus, which is an eyed, short-legged, shiny,
fast-moving carabid beetle with full-length elytra;
and Batrisodes uncicornis, an eyed species occurring
in many caves in
both blind and eyed, occur in caves outside the range
of this species (
Listed: Because Batrisodes texanus was considered to
be Texamaurops reddelli before
redescription (1992) and one locality (
B. texanus was included with Texamaurops reddelli at
the time Texamaurops reddelli was listed as endangered
considered to be listed as endangered under the
Endangered Species Act. The USFWS has reviewed the
species description (
available information on this species and determined
it should remain listed as endangered (58 FR 43818).
Recovery Priority: 2C
Population estimates: No population estimates are
currently available for any of the species due to their
secretive habits, rarity, and inaccessibility. Generally,
no more than one or two individuals of each species are
seen on a visit to a cave and often none are observed, even
in caves where they are considered relatively abundant.
Some of the species, such as the pseudoscorpion and mold
beetles, are so secretive that finding an individual is a
rare event (Elliott, pers. observation) . Current mark-
recapture methods are of little use with such small
Historic range: Since karst surveys and biospeleological
studies in the
early 1960’s, there is no information on the species’
ranges prior to that time. Further, the status of some of
the caves from which listed species have been collected is
unknown. Some of these caves may have been filled or
destroyed due to land development. For example, attempts to
have been unsuccessful (
Museum, pers. communication)
Current range: The level of interest and effort in
conducting karst and biospeleological surveys greatly
increased with the listing of the invertebrate species in
1988. Regional studies were funded
by the USFWS, the
Parks and Wildlife Department (TPWD), the Texas Department
of Transportation, the
the City of
1989, Reddell 1991, Reddell and Elliott 1991, Veni &
Associates 1988a,b). Additional surveys have been done by
developers, financial institutions, and private landowners.
These studies have assisted in clarifying the range and
taxonomy of each species. Although additional localities
for each species may still be discovered with continuing
survey efforts, the species’ ranges are now fairly well-
defined, particularly for those species that are restricted
to the Jollyville Plateau (Neoleptoneta myopica,
Tartarocreagris texana, and Texamaurops reddelli)
Some specimens collected from certain localities have
been tentatively identified as listed species (Tables 1 and
2). Positive identification of these specimens is
contingent upon identification by a qualified systematist
and/or additional collections including well-preserved,
intact adult specimens. The information in these tables
will be revised and updated as positive identifications are
Figure 1 shows all the caves in Travis and Williamson
counties currently known to contain one or more of the
listed species or from which tentative identifications have
been made. Figure 2 shows the seven karst fauna regions
(corresponding to the karst fauna areas in Figure 19 of
Veni & Associates 1992) that support one or more of the
listed species. The
in the figure even though it is not currently known to have
listed species. It is included in the event that future
surveys locate any listed species in this region. To date,
no listed species have been found in the caves that have
been surveyed in the
local biospeleologists believe that portions of the South
investigation to determine whether there are karst features
inhabited by listed species, particularly along the south
side of Barton Creek. The species most likely to occur in
this region is Texella reddelli, which occurs in the adjacent Rollingwood karst fauna region. Since this
species’ current distribution occurs on both sides of the
Creek, which separates the Rollingwood and South Travis
County karst fauna regions.
Two karst fauna regions from Veni’s 1992 report, the
McNeil and Round Rock regions, have been combined for the
purposes of this plan (hereafter referred to as the
McNeil/Round Rock karst fauna region), since they contain
virtually the same species and present no significant
geologic barriers to troglobitic migration between them
(Veni, in litt., 1993).
The distribution of each species is as follows:
SPECIES 1 - Neoleptoneta myopica: Known to occur
in two caves and tentatively identified from two
additional caves within a 4.5 km stretch in the
Jollyville Plateau karst fauna region, Travis
SPECIES 2 - Tartarocreagris texana: Known to
occur in two caves and tentatively identified
from two additional caves within a 1.3 km radius
in the Jollyville Plateau karst fauna region,
SPECIES 3 - Texella reddelli: Occurs in three
caves (one positive, two tentative
identifications) in the Jollyville Plateau karst
fauna region and four caves (one positive, three
tentative identifications) in the Rollingwood
karst fauna region, Travis County, Texas (Table
1, Figure 5). Previously reported from Tooth,
McDonald, Weldon, and Root caves,
(53 FR 36029), but these populations have been
redescribed as Texella reyesi (Ubick and Briggs
1992) (58 FR 43818). Kretschmarr Double Pit,
The other four caves are located in the
Rollingwood karst fauna region, south of the
collections do not include the male specimens
necessary to confirm the occurrence of this
species. However, the females are similar to the
females collected from
on opposite sides of the
different blocks of limestone may be an
indication that the populations are genetically
SPECIES 4 - Texella reyesi: Occurs in 69 caves
(60 confirmed, 9 tentative identifications) from
northern Travis to northern
distance of 40 km (Tables 1 and 2, Figure 6).
This species occurs in six karst fauna regions
(1967) described Texella reddelli they included
four populations, three of which are now
recognized as Texella reyesi (
(1992) redescription of Texella mulaiki included
four populations, three of which are now
recognized as Texella reyesi (
County (58 FR 43818))
SPECIES 5 - Rhadine persephone: Occurs in ten
caves (8 positive, 2 tentative identifications)
in the Jollyville Plateau karst fauna region
1 tentative identifications) in the
karst fauna region (Travis and Williamson
counties) (Tables 1 and 2, Figure 7), with a
total distance of about 14 km between the
northern and southernmost locations. Sympatric
in at least four caves with a slender species, R.
SPECIES 6 - Texamaurops reddelli: Known to occur
in four caves within a 2 km radius in the
Jollyville Plateau karst fauna region, Travis
FR 36029), but the
been redescribed as Batrisodes texanus
1992) (58 FR 43818)
SPECIES 7 - Batrisodes texanus: Occurs in two
caves in the
region (both positive identifications) and three
caves (two positive, one tentative
identification) in the
9) . All localities occur within a 17 km stretch.
Of the seven listed species, Rhadine persephone and
Texella reyesi are the only two known from more than seven
sites. Rhadine persephone appears to be restricted to
sites within the
fauna regions (Figure 7). Texella reyesi has both the
greatest number of sites and the widest distribution,
occurring in six karst fauna regions (Figure 6). Texella
reddelli is the only species that occurs both north and
south of the
Except for Batrisodes texanus, which occurs only in
ranges include the Jollyville Plateau karst fauna region in
myopica, Tartarocreagris texana, and Texamaurops reddelli)
occur entirely within this region. One cave cluster,
located in the vicinity of the RM 2222 and RM 620
intersection in a proposed residential subdivision, harbors
six of the listed species. This cluster supports one of
the most diverse, terrestrial, cave-adapted faunas in the
cave systems, such as
more diverse faunas.
cluster and contains five of the listed species. Stovepipe
Cave, located to the northeast, also contains five of the
Many of the reconnaissance studies conducted since
1988 have resulted in the discovery of new localities for
the listed species as well as new endemic species. Because
current methods of locating karst features are time
intensive and require on-site inspections, many areas
within each karst fauna region have not yet been surveyed.
As surveying efforts continue, new localities may be
discovered in all karst fauna regions. To date, karst
fauna regions that have received the least amount of study
northwestern part of
study. A large knowledge gap also exists between Round
to the property is limited. The
Society (TSS), a private, non-profit research group,
recorded numerous caves in that area in 1963, but none have
been investigated recently. Many of those caves may still
In addition to continuing surveys for new endangered
species localities, more intensive biospeleological studies
of currently known karst features may also provide
additional information on species distributions. More than
700 karst features have been located in Travis and
Williamson counties (Elliott, pers. communication), of
which about 100 are known or believed (through tentative
identification of collected specimens) to contain
endangered species (tables 1 and 2). Biospeleological
surveys of many of the remaining karst features are either
nonexistent, outdated (e.g. recent surveys have not been
conducted), incomplete, or cursory. Detailed faunal
surveys of those features that have not been adequately
studied but which could support one or more of the listed
species may lead to the discovery of additional endangered
species localities. Although these surveys may increase
the total number of known locations for the karst
invertebrates, most new locations will occur within the
currently defined range of each species. The overall range
of each species is not expected to increase significantly
beyond what is defined in this plan.
C. Habitat, Ecosystem, and Ecology
Little is known about the life history, ecology, and
habitat requirements of the listed species and other karst
fauna in central
emphasis has been on taxonomy, biogeography, and a few
behavioral studies (Barr 1974a,b; Barr and Steeves 1963;
Bull and Mitchell 1972; Christiansen and Culver 1969;
Elliott and Mitchell 1973; Elliott 1976, 1978a,b; Gertsch
1974; Goodnight and Goodnight 1967; Holsinger 1967; Maguire
1960; Mitchell 1968a,b,c, 1970; Mitchell and Reddell 1971;
Muchmore 1969; Reddell 1965, 1966, 1967, 1970a-c), and more
recently on geologic and hydrologic processes of karst
(Veni & Associates 1988a,b, 1992). Elliott (1991a-f,
1992b-e) has begun a long-term, baseline ecology study of
three caves as part of the LakeLine Mall Habitat
Conservation Plan (see discussion in Section E).
Origin of Karst Features: “Karst” is a type of terrain
that is formed by the slow dissolution of calcium carbonate
from limestone bedrock by mildly acidic groundwater. This
process creates numerous subterranean voids (caves,
sinkholes, fractures, interconnections, etc.) so that the
bedrock somewhat resembles a honeycomb. The formation of
these features depends largely on the solubility of the
bedrock and the rate and direction of groundwater movement.
Water enters the subsurface through cracks, crevices, and
other openings, dissolving away soluble beds of rock as it
moves through the ground, until it discharges downhill at
a spring outlet.
Many of the karst features occupied by the listed
species were formed at or below the water table, and thus
were once filled with water. As the groundwater table
lowered through canyon downcutting and regional uplift,
these features dried out and are now air-filled. These
features are referred to as “dry” because they tend to
have small catchment areas, take very little runoff, and
contain little or no perennially flowing water. In some
cases, cave and sinkhole entrances were formed as the
groundwater table lowered, resulting in ceiling collapse of
Some karst features may act as recharge structures to
underground stream systems. For example, Buttercup Creek
overlies an important karst network composed of several
caves such as
sinkholes and caves that may contribute to an underground
infeeder to the system. Available information indicates
that the stream exits either at a spring in Bull Creek to
the south, which contributes to
feeds into the northern pool of the Edwards Aquifer.
Evolution of Troglobites: Troglobites have been referred
to as “relicts” of surface soil and leaf-litter faunas. A
widely accepted explanation for the evolution of
troglobites is that, during the course of climatic changes
in the Pleistocene epoch (two million to ten thousand years
ago), certain creatures retreated into the more stable cave
environments, while their respective surface relatives
either emigrated or became extinct (Barr 1968, Mitchell and
Reddell 1971, Elliott and Reddell 1989). The troglobitic
species survived and adapted to the cave environment and
colonized the caves and other subterranean voids. Through
faulting and canyon downcutting, the karst terrain along
the Balcones Fault Zone became increasingly dissected,
particularly around the Jollyville Plateau, creating
“islands” of karst and barriers to dispersal. This led to
increasing isolation of troglobitic populations from each
other with subsequent speciation. Some groups speciate
very readily, while others appear to speciate more slowly.
Some species are more mobile than others and can achieve
larger ranges. The restricted distribution of troglobitic
species makes many of them highly susceptible to extinction
(Elliott and Reddell 1989).
Habitat Requirements - Moisture and Temperature:
Troglobites require high humidities (nearly l00%), and many
are very susceptible to drying. Generally, areas within
caves that have low humidities are almost entirely devoid
of cave fauna (Elliott and Reddell 1989, Barr 1968). Caves
that are encased with an inner shell of calcite, which can
cut off water and nutrient infiltration, are also nearly
biologically sterile (Elliott, pers. observation).
Water enters the karst ecosystem though groundwater
and surface drainage. Well-developed pathways, such as
cave openings, fractures, and solutionally enlarged bedding
planes, rapidly transport water through karst with little
or no purification. Caves are susceptible to pollution
from contaminated water entering the ground because karst
has little capacity for self-purification. The route that
has the greatest potential to carry water-borne
contaminants into the karst ecosystem is through the
surface and subsurface drainage basin that supplies water
to the ecosystem. Certain activities within this
hydrologically sensitive area, such as application of
pesticides and fertilizers, leakage from sewer lines, and
urban runoff, could contaminate the karst ecosystem. The
potential for contaminants to travel through karst systems
may be increased in some areas relative to others due to
local geologic features.
Most troglobites require stable temperatures. Cold,
dry air entering a cave causes the fauna to retreat to more
humid, warmer recesses (Reddell and Elliott 1991). During
these times, some troglobites may be found in small ceiling
pockets where the conditions are presumably warmer and
damper, rather than on the floor where they are normally
found (Elliott, pers. observation). During hot, dry periods, cave fauna may retreat into the cave soil or interstitial spaces where environmental conditions are more stable (Howarth 1983).
Habitat Requirements - Importance of Surface Communities:
Due to the paucity of light and limited capability for
photosynthesis, karst ecosystems are almost entirely
dependent upon surface plant and animal communities for
nutrient and energy input. Karst ecosystems receive
nutrients from the surface in the form of leaf litter and
other organic debris that have washed or fallen into the
caves, from tree and other vascular plant roots, or through
the feces, eggs, or dead bodies of troglophiles and
trogoxenes (for example, cave crickets, raccoons).
Certain animal species, such as cave crickets, daddy
longlegs, and raccoons appear to use most caves, provided
there is sufficient area on the surface with habitat to
support these species and the cave entrance is not blocked.
A study to determine the foraging range and spatial/temporal distributions of cave crickets and daddy longlegs is currently underway as part of the LakeLine Mall Habitat Conservation Plan (see discussion in Section E). Recent research indicates cave crickets may forage more than 50 meters from cave entrances (W.R. Elliott, pers. comm., 1993).
Cave crickets (Ceuthophilus spp.) are an especially
important component of the cave ecosystem, because many
invertebrates are known to feed on their eggs, feces,
nymphs, and dead body parts. Cave crickets typically roost
and lay eggs in caves during the day, then emerge at night
to feed. They are general predators and scavengers, but
the exact food preferences of Ceuthophilus species in
are still unclear. Daddy longlegs harvestmen (Leiobunum
townsendii), which are abundant in many caves, may
similarly introduce nutrients into the cave ecosystem.
Raccoons are also ecologically important in many cave
communities because their feces provide a rich medium for
the growth of fungi and, subsequently, localized population
blooms of several species of collembolans. Collembolans
are tiny, hopping insects that reproduce rapidly on rich
food sources and may become prey for some predatory
Caves with large bat colonies usually harbor a
community dominated by guano-feeders and related species.
Some of the small caves of Travis and Williamson counties
once harbored small bat colonies, usually cave bats (Myotis
velifer). This species often abandons caves because of
human disturbance or other factors (Elliott, in press).
However, most of the caves inhabited by the listed species
were not significant bat roosts in the past. The exceptions
to this rule follow: 1)
small bat colony at one time, but has not contained bats
for many years (Reddell, pers. communication); 2) Steam
some Myotis velifer individuals, according to numerous
cavers’ reports; 3) On Campus Cave at
apparently a major bat cave at one time, was sealed during
land development, then reopened in 1992 (Mike Warton,
geologist, pers. communication); 4) Beck Bat, Beck Horse,
and Beck Ranch caves have had bat colonies at different
times (Elliott, pers. observation). These data suggest
that although the karst ecosystems containing the listed
species may not depend on bats for nutrient input, some of
the listed species can tolerate conditions around small bat
colonies and may benefit from the increased nutrients.
Surface plant communities around karst features
supporting the listed species range from pasture land to
mature oak-juniper woodland. In general, exotic plants and
animals (particularly fire ants) are believed to be
detrimental and may result in competition with or predation
upon native species and a decreased overall species
In addition to providing nutrients to the karst
ecosystem, the surface plant community also serves to
buffer the karst ecosystem against changes in the
temperature and moisture regimes, pollutants entering from
the surface (Biological Advisory Team 1990, Veni &
Associates 1988a), and other factors such as sedimentation
from soil erosion. Protecting native vegetation may also
help control certain exotics (such as fire ants) that may
compete with and/or prey upon the listed species and other
karst fauna. Fire ants are particularly detrimental to
karst ecosystems, although the full extent of their impact
has not yet been determined. Soil disturbance,
introduction of nursery plants and sod containing fire
ants, garbage (potential food source), and electrical
equipment are some of the factors contributing to fire ant
Habitat Requirements - Use of Interstitial Spaces: The
extent to which the species use small humanly inaccessible
voids, referred to as “interstitial spaces” (such as
fractures, fissures, cracks, etc.), between or around caves
is not fully known. Use of interstitial spaces by
troglobites has been observed in
(Howarth 1983). At the LakeLine Mall site in Williamson
County (see Section B), six boreholes (referred to as
“coreholes” in certain documents) were drilled to determine
the presence of interstitial fauna. The two caves on the
species (Rhadine persephone and Texella reyesi). Four to
five Rhadine persephone beetles and one Rhadine subterranea
beetle were found in one of the four boreholes thatencountered a void (Well Trap #6, Table 2). This void was
located about 600 feet northwest of
five boreholes (Horizon Environmental Services, Inc.
Howarth (1983) refers to these interstitial
communities as “crack fauna” and asserts that “caves are
not isolated but connect with other subterranean habitats
to constitute a single functioning system”. He argues that
troglobites primarily live in interstitial spaces, where
environmental conditions are more stable, but will venture
into larger voids and caves when conditions are suitable.
Some troglobites have a lower metabolic rate and are able
to use energy more efficiently than their surface
relatives, and many have exhibited the ability to withstand
long periods without consuming food. Thus, a steady food
supply for these species may not be as limiting a factor as
the need for high moisture levels and stable temperatures.
This may explain the seasonal distribution of the cave
fauna and the apparent paucity of troglobites during
periods of dryness or temperature extremes (Howarth 1983)
Troglobites occupying interstitial spaces may receive
nutrients through root systems of surface vegetation and
through many small holes and fissures in karst areas where
raccoons, cave crickets, and other surface fauna can enter
the subsurface. Groundwater flow and surface infiltration
are also vehicles for transporting nutrients through
interstitial spaces. Certain strata in the Edwards
Limestone are more prone to developing karstic solutional
openings and thus may be more penetrable by nutrients than
other strata. The extent of nutrient infiltration into the
interstitium appears to be site-specific and is largely
dependent on the nature of the limestone strata and the
juxtaposition of subterranean voids. Thus, some strata may
receive nutrient input over a large area, while others may
receive input only through caves and sinkholes.
The distance that the listed species or other karst
fauna retreat from cave openings is unknown but is probably
dependent upon the presence of contiguous voids large
enough for the fauna to occupy, proximity to nutrient
supplies, and the ecological requirements of the species.
For example, if the “epikarst” (the surface of the karst)
is extremely honeycombed, as in the LakeLine Mall area,
then troglobites may be found where there are continuous
passages or open bedding planes. Furthermore, more mobile
species, such as Rhadine persephone, may range farther from
cave openings, while more sedentary species, such as
Neoleptoneta myopica, may be physically restricted to
Habitat Requirements - Management Considerations: The
karst features inhabited by these species and the
ecosystems on which they depend have evolved slowly over
millions of years and cannot be recreated once they have
been destroyed. Protection of these ecosystems will
require maintaining moist, humid conditions and stable
temperatures in the air-filled voids; maintaining an
adequate nutrient supply; preventing contamination of the
water entering the ecosystem; preventing or controlling
invasion of exotic species, such as fire ants; and other
actions as deemed necessary. Additional research may help
to develop or refine conservation and management practices
necessary to achieve these goals.
In determining appropriate management techniques of
surface communities, the ecological requirements of other
species, such as the federally listed endangered black-
capped vireo (Vireo atricapillus) and golden-cheeked
warbler (Dendroica chrysoparia), whose ranges overlap with
those of the listed invertebrates, will also need to be
considered. Recovery plans for these species have been
prepared (USFWS 1991, 1992)
Ecology: Most of the endangered karst invertebrates are
believed to be predators of microarthropods, such as
collembolans. Many troglobites also feed on well-
decomposed organic matter. Others, such as the ground
beetle, may consume cave cricket eggs or dead cave cricket
parts. The limited data available suggest that most
troglobites are food generalists (Barr 1968), although this
does not preclude the development of food specialization in
some species. Since several predator species coexist in
most caves, one can expect some degree of prey
specialization in these species.
Elliott and Reddell (1989) note that “there is no
direct information on the life cycle of any of these
species. Many surface relatives have a distinct seasonal
life cycle, but collections throughout the year indicate
that all of these species have lost this seasonality...”
The following list summarizes currently available on each
Species 1 - Neoleptoneta myopica: This species preys on
microarthropods and has been described as a “sedentary
aerial spider that hangs from a small tangle or sheet web
on long, thin legs” (Gertsch 1974). Mitchell and Reddell
(1971) observed that “in
spiders are the most important animals filling the ‘small
predator’ niches.” Since a cave can contain several
different species of spiders, such as members of the genera
Neoleptoneta, Cicurina, Nesticus, and Eidmannella, slightly
different small predator niches apparently have developed
in those communities. For example, in
County, there are 11 co-existing, troglobitic, small
predators (6 spiders, a harvestman, 2 pseudoscorpions, and
2 Rhadine beetles) (Elliott and Reddell 1989).
Species 2 - Tartarocreagris texana: Tartarocreagris texana
is usually found under rocks. Finding individuals of this
species is so rare that little else is known of its habits
(Elliott and Reddell 1989). All known pseudoscorpions are
predators of microarthropods.
Species 3 - Texella reddelli: This species is usually
found under rocks in darkness or in dim twilight. All
phalangodids have large, raptorial pedipalps designed to
seize and hold prey. Elliott (1978b) observed that
Banksula melones and Banksula grahami, members of the same
(psocopterans) and collembolans placed in small containers,
but preferred the collembolans, which were smaller.
Texella and other small harvestmen tend to walk rather
slowly and deliberately, unlike spiders, which tend to move
faster. See further remarks on Texella reyesi.
Species 4 - Texella reyesi: This species is especially
sensitive to drying and requires very moist, humid
conditions (Elliott 1991a-f and unpublished data). Most
individuals are found under large rocks, but are
occasionally seen walking on moist floors. In
the entrance in total darkness, where humidity is high;
they seldom occur farther in the cave where there is less
water and food. In the hottest part of the summer when
many of the small caves warm up and become drier,
individuals may retreat into the interstitium or may be
found only in the coolest, dampest spots in the caves.
This species feeds on microarthropods. One individual in
Species 5 - Rhadine persephone: Rhadine persephone is the
largest, most visible, and most active of the species and
is sometimes visible in strong light from a distance of 5
to 10 m. Rhadine persephone is usually found under rocks,
although some individuals have been observed walking on
damp rocks and silt. The beetle runs rapidly and patrols
the floor area in search of prey, as does R. subterranea,
a closely related and sympatric species.
While feeding behavior has not been observed in R.
persephone, Mitchell (1968a, b) observed R. subterranea
feeding on cave cricket eggs and dead cave cricket parts in
communication, in Mitchell 1968b) reported one observation
of a R. subterranea beetle carrying a collembolan. Rhadine
subterranea appears to be restricted to areas of deep,
uncompacted silt, where it digs holes to remove and feed on
eggs deposited into the silt by cave crickets. Mitchell
also found R. subterranea larvae in the silt, but he felt
the food supply was the limiting factor in the beetle’s
distribution. Rhadine subterranea is not believed to feed
on organic material, fungi, raccoon feces, cricket
droppings, or live cave cricket nymphs, as are some other
invertebrates. Fungi may harbor parasites that result in
beetle mortality. Predation on cave cricket eggs has
apparently evolved in at least four different genera of
troglobitic carabid beetles in
in 1965, R. persephone are more abundant than R.
subterranea. The high population levels of R. subterranea
in the Round Rock and
with its rarity at the southern margin of its range (for
further range extension may be checked by interspecific
competition. Competition due to broad niche overlap
between R. persephone and R. subterranea may limit the
latter in Tooth and Kretschmarr caves (Barr 1974a)
On one occasion Elliott (1992b) observed Rhadine
This may indicate a residual nocturnal behavior, similar to
that seen in fully-eyed species of Rhadine beetles observed
in caves on the
Species 6 - Texamaurops reddelli: Texamaurops reddelli is
found in total darkness under and among rocks and buried in
silt (Barr and Steeves 1963, Reddell 1966). All members of
the family are believed to be predators. Both Texamaurops
reddelli and Batrisodes texanus (below) have well-developed
mouth parts and are also believed to be predators (Donald
Hampshire, in litt., 1993). Pselaphids are found in soil,
moldy wood, moss, under stones and logs, in caves, or in
termite nests. The term “mold beetle” refers to an old
definition of “mold” as rotting plant material.
Species 7 - Batrisodes texanus: Batrisodes texanus is
found in total darkness under rocks. In Off
it was found on the underside of a rock lightly buried in
silty clay in total darkness (
Space Cavern in August 1968, Elliott (unpublished data)
collected a female as it ran from under a moldy match box
in the Mud Room. It is believed to be a predator (see
Texamaurops reddelli, above).
D. Reasons for Listing and Current Threats
One of the main threats to the listed species is loss
of habitat due to urban development activities (53 FR
36029). The species occur in an area that is undergoing
continued urban expansion at a rapid rate and few caves are
adequately protected. Most of the species’ localities
occur adjacent to or near developed areas (residential
subdivisions, schools, golf courses, roads, commercial and
industrial facilities, etc.) or in areas that are proposed
for development. Unless proper protective measures can be
devised, urban development may lead to the filling in or
collapse of caves, alteration of drainage patterns,
alteration of surface plant and animal communities, as well
as increased contamination and human visitation.
One cave cluster in the Jollyville Plateau karst fauna
region occurs in an area that presently supports some
residential and industrial development and where additional
development has been proposed. Another cave to the north
of this cave cluster occurs in an area that is undergoing
expansion of a residential community. These two areas
support six of the listed species and include the entire
ranges of Tartarocreagris texana and Texamaurops reddelli.
Filling in and Collapsing of Caves: Some caves have been
filled, collapsed, or otherwise altered during road
construction and building site preparation (53 FR 36029).
Various construction and development activities over caves
or sinkholes may also result in the collapse of cave
ceilings. There are limited data available on the number
of caves that have been filled to date. Elliott and
Reddell (1989) estimate that at least 10% of the caves in
will only accelerate with increasing urban expansion. To
date, two caves containing Texella reyesi are known to have
been filled (Fossil and Sore-ped caves).
filled in 1991 by the owner but was reopened after
negotiations with the USFWS.
1980 and has not been reopened.
Trap #6 will be destroyed as part of the LakeLine Mall
Section 10 (a) (1) (B) permit (see discussion in Section E)
Other caves (such as
texanus) may already have been filled due to recent
development. Attempts to relocate
unsuccessful (53 FR 36029)
Ranching activities may also lead to the filling of
cave entrances. The earliest published reference to local
ranchers routinely filling cave entrances was by Vinther
and Jackson (1948), who stated that entrances were closed
‘varmints’— predatory animals.” Ranchers sometimes fill
entrances or cover cave entrances by placing “cedar”
(juniper) limbs across entrances to prevent cattle and
goats from falling in (Elliott, pers. observations).
Alteration of Drainage Patterns: Because karst ecosystems
depend on air-filled voids with some water infiltration,
diverting water away from a cave could lead to drying and
subsequent mortality of karst fauna, while increasing water
infiltration could lead to flooding and loss of air-breathing species. Altering the quantity of water inflow
could also result in changes in the nutrient regime.
Development activities that result in the alteration
of natural drainage patterns include altering the
topography, increasing impervious cover, installing water
collecting devices, spray-irrigation systems, and other
activities. Opening too many or too large entrances into
a cave system during cave exploration may also result in
drying. The extent to which these activities are impacting
the listed species’ localities needs to be determined.
Alteration of Surface Plant and Animal Communities: Land
development and other human activities (such as
agriculture) can lead to the loss of surface plant and
animal communities on which karst ecosystems depend for
nutrient supplies. With urbanization, native vegetation
may be removed and replaced with impervious cover, nursery
plants, and/or exotic plants. Subsequent changes in the
animal community include the introduction of exotics, such
as fire ants; loss or reduction of certain animals due to
habitat loss, competition, predation, or other factors; and
overall declines in species diversity. Many of these
plants and animals (for example, cave crickets and daddy
longlegs) may be critical to the nutrient regime of the
karst ecosystem, and loss of these species could lead to
nutrient reduction or depletion within the karst ecosystem.
Removal of the native surface vegetation may lead to
increases in temperature fluctuations, changes in the
moisture regime, increased potential for contamination, and
increases in sedimentation in the caves from soil erosion
on the surface.
The impacts that altering surface plant and animal
communities have on karst ecosystems are not fully
understood and warrant further research. Important
contributors to the karst ecosystem’s nutrient regime need
to be identified, as well as the surface area and other
ecological requirements necessary to sustain these nutrient
sources. Some of this information will be gathered as part
of the LakeLine Mall Habitat Conservation Plan’s studies
(see discussion in Section E)
Contamination: Because karst is highly susceptible to
groundwater contamination, urbanization (including
industrial, residential, road, and commercial development)
may result in the contamination of karst ecosystems. Types
of contaminants associated with urbanization may include
chemical, sewage, and oil pollution. These pollutants are
derived from urban runoff; broadcasting, spraying, and
fogging pesticides and fertilizers; hazardous materials
spills; pipeline and storage tank leaks; power transformer
and industrial accidents; leakage from septic systems,
landfills, and sewer lines; and other sources.
Primary routes of contaminant entry into karst
ecosystems include the surface and subsurface drainage
basin of a karst ecosystem; air (for air-borne
contaminants); and dumping of household garbage,
construction debris, motor oil, alkaline batteries (which
contain mercury), pesticides and other materials directly
into cave entrances. Many caves are currently subject to
disposal of refuse, urban runoff, and contamination from
pesticides and fertilizers. Several chemical facilities
are located along RM 2222 in the Jollyville Plateau karst
fauna region near caves known to support six of the listed
species. A cave containing Texella reyesi is directly
under an oil pipeline. Provisions for protecting karst
ecosystems from contamination need to be developed.
Human Visitation, Vandalism, and Dumping: Urban
development near cave entrances is likely to increase human
visitation to these caves. Possible impacts from human
entry into a cave include habitat disturbance or loss due
to soil compaction or changes in atmospheric conditions,
abandonment of the cave by bats or other trogloxenes, and
direct mortality (e.g., from stepping on karst fauna).
These impacts may be reduced or avoided, depending on the
caving skills and caution of the person(s) entering the
cave. Vandalism may also result in the destruction or
deterioration of the karst ecosystem. Dumping of toxic
trash (such as alkaline batteries) can lead to
contamination of the karst ecosystem. Disposal of
household and other wastes may also attract fire ants.
Cave gates and fences are often installed to deter
unauthorized human visitation and dumping; however, these
devices may inadvertently alter the air flow, moisture, and
nutrient regimes of the karst ecosystem. Installation of
a cave gate may also destroy the aesthetics of the cave
opening. Furthermore, the soil disturbance generated
during the installation of cave gates and fences may
encourage fire ant infestations in these areas.
Nonetheless, carefully constructed and monitored cave gates
and fences are appropriate in some situations and should be
considered as an option at heavily visited or vandalized
caves. Caves gates are further discussed in Tasks 4.3 and
Fire ants: Fire ant activity in central
have increased dramatically since 1989 (Elliott 1992a).
The fire ant is an aggressive predator, and current
evidence shows that it has a devastating and long-lasting
impact on native ant populations and other arthropod
communities (Vinson and Sorenson 1986; Porter and Savignano
1990). Fire ants have been observed building nests both
within and near cave entrances as well as foraging in
caves, especially during the summer.
The relative accessibility of the shallow caves
inhabited by the listed invertebrates makes them especially
vulnerable to invasion by fire ants and other exotic
species. Fire ants can enter karst ecosystems through the
cave entrance or through small holes from the surface and
attack karst fauna in areas that humans cannot observe.
Fire ants have been found in more than 50 percent of the
caves that contain listed karst invertebrates and have been
observed attacking and preying on several troglobitic
species, as well as scorpions, cave crickets, and other
karst dwellers (
litt., 1993). Karst fauna that are most vulnerable to fire
ant predation are the slower-moving adults, nymphs, and
eggs. (Reddell, pers. communication). Even in the unlikely
event that fire ants do not prey directly upon the listed
invertebrates, their presence in and around karst areas
could have a drastic detrimental effect on the karst
ecosystem through loss of both surface and subsurface
species that are critical links in the food chain.
Fire ant colonies occur in two forms: single-queen and
multiple-queen colonies. Multiple-queen fire ant colonies
occur in very dense concentrations (about 750-5000 mounds
per acre) and successfully dominate areas previously
occupied by the less dense (100-200 mounds/acre) single-
queen form (Porter et al. 1991). The multiple-queen form
is three times more abundant in
of its range and recent surveys indicate it is spreading.
This form invaded the
1980’s (Porter et al. 1991).
Fire ant studies conducted by Porter et al. (1988) in
In the first phase, fire ant queens invade an area through
long-distance dispersal of winged queens or are introduced
through imported products such as nursery stock or soil
containing small fire ant colonies. Their invasion is
aided by “any disturbance that clears a site of heavy
vegetation and disrupts the native ant community.” Several
native ants are known to attack and kill founding fire ant
queens. These native ants are especially important in
eliminating founding fire ant queens and their colonies
from non-infested areas. Once the fire ant becomes
established, they enter the second phase during which the
native ant communities are gradually eliminated and show
little resurgence as the fire ant slowly expands and
increases in number. This phase takes many years to
complete (Porter et al. 1988) . These factors should be
considered when determining short and long-term methods of
fire ant control.
Mining, quarrying, or blasting above/in caves: There are
several limestone quarries in the
contain suitable habitat for one or more of the listed
species. Vinther and Jackson (1948) reported three caves
and Finch (1963) reported two other caves in this area that
were destroyed in 1960 and 1963 by quarry activities and at
least 22 other caves and sinks on ranches that are now part
of or adjacent to that quarry. Both Batrisodes texanus and
Texella reyesi occur in caves to the north of this quarry.
Other quarry properties in the area may still contain
E. Conservation Measures
This section summarizes the regional karst and
biospeleological surveys, research, and other conservation
measures that have been conducted to date.
Regional karst and biospeleological surveys: Since the
listing of the endangered species, numerous surveys have
been conducted to better define the distribution and
taxonomy of karst fauna in Travis and Williamson counties.
Many of the studies are proprietary reconnaissance studies
conducted by environmental consultants, geologists,
engineers, cavers, and biospeleologists to locate caves and
sinkholes on properties proposed for development. These
studies have been funded primarily by private landowners,
financial institutions, school districts, and governmental
agencies and have resulted in the discovery of new
endangered species localities.
In early 1989, the Texas Department of Transportation
(formerly known as the Texas Department of Highways and
Public Transportation) sponsored a karst feature survey and
biospeleological study of karst features along the
right-of-way of the proposed
Highway 45) from Comanche Trail to
That same year, Elliott and Reddell (1989) completed a
major study of several caves in Travis and Williamson
counties to further define the status and range of the
listed species. Elliott and Reddell’s surveys were funded
by TPWD and TNC in preparation for a regional endangered
species conservation effort involving local and state
government and several conservation organizations. The
report also discussed cave ecology, scientific and economic
values of cave faunas, destruction rates of
caves, and threats to cave fauna. Acquisition, scientific,
and management recommendations were also given, including
long-term ecological studies, stewardship programs,
cooperative agreements, and greenbelts. Through an
Endangered Species Act Section 6 cooperative agreement with
TPWD, USFWS funded continued karst and biospeleological
studies by Reddell and his associates (1991). These
studies helped further clarify the range of the listed
species and determine areas that warranted additional
From 1990 to 1991,
the City of
extensive study of 21 caves and 19 other karst features in
Elliott 1991). As a result of the study, Temples of Thor
and Red Crevice caves were discovered and later sold to
Melvin Simon & Associates, Inc. to become part of the
LakeLine Mall Habitat Conservation Plan. Known cave
locations from the Texas Speleological Society files were
mapped onto the City of
Through an Endangered Species Act Section 6
cooperative agreement with TPWD, the USFWS funded a study
(Veni & Associates 1992) of geologic controls on cave
development and the distribution of karst fauna in the
vicinity of Travis and Williamson counties. This study
significantly improved the ability to predict where
endangered species’ localities might occur in Travis and
Williamson counties. Veni divided Travis, Williamson,
Hays, and Burnet counties into 11 areas (referred to as
“karst fauna regions” in this recovery plan) based on
geologic continuity, hydrology, and the distribution of 38
rare troglobites. By correlating distribution data for the
38 troglobites to the 11 karst fauna regions, Veni observed
that the Jollyville Plateau,
Ridge regions have more endemic species than McNeil, Round
McNeil and Round Rock karst fauna regions have been
combined, and areas where listed species do not occur have
been omitted from Figure 2, with the exception of South
Veni and Associates (1992) mapped four zones in Travis
and Williamson Counties indicating areas with different
likelihoods of having extensive cave development and listed
species. The boundaries are matched to known outcrops of
cavernous limestone garnered from numerous geologic maps
and studies and to hydrologic boundaries extrapolated from
the elevations of cave passages compared to surface water
divides. Zone 1 includes areas in the Edwards Group
limestones that are known to contain listed species. Zone
2 comprises areas that may contain listed species or other
endemic fauna. Zone 3 probably does not contain listed
species or their habitat, and Zone 4 consists of
noncavernous rock and thus does not contain caves or other
karst features. Together, Zones 1 and 2 comprise about
55,000 acres in
Fire ant control study: In 1991, USFWS funded, through a
Section 6 cooperative agreement with TPWD, a fire ant
control study in and around 12 caves containing listed
species in Travis and Williamson counties (Elliott 1992a).
Three types of treatments were used including hot (nearly
boiling) water, and the chemicals Amdro® and Logic®.
Additional research is needed to determine the
effectiveness of the treatments against fire ants and
effects on the listed species.
Both Logic® and Amdro® are harmful to arthropods. Use
of Amdro or Logic may result in the mortality of the
endangered species through consumption of the chemical(s)
or contaminated prey which have ingested the bait. Adverse
impacts to the species may be avoided through strict
control of chemical applications. For example, applying
chemical baits away from the cave entrance and outside of
areas used by cave crickets may prevent introduction of the
active ingredients into the food chain. By applying
chemicals in the morning under dry, warm conditions, the
ants may consume most or all of the chemicals before cave
crickets exit the cave at sundown to forage.
Despite effective initial treatments, some areas may
be rapidly re-infested with fire ants from surrounding
areas, as happened at
more than one treatment each year. The level and type of
fire ant control necessary for each area will likely be
site-specific, depending on adjacent land use and severity
of the fire ant infestation.
LakeLine Mall Habitat Conservation Plan (HCP): On February
13, 1992, the USFWS issued a Section 10(a) (1) (B) permit
under the Endangered Species Act to Melvin Simon and
Associates, Inc., to allow the “taking” of some Rhadine
persephone and Texella reyesi individuals as a result of
the proposed LakeLine Mall development. The Endangered
Species Act authorizes the USFWS to permit the taking of
federally listed species if such taking is “incidental to,
and not the purpose of, the carrying out of an otherwise
lawful activity” (16 U.S.C. Section 1539). Two caves
(LakeLine and Underline) and one bore-hole (Well Trap #6)
were found to contain listed species.
contains T. reyesi, and Well Trap #6 contains R.
during mall construction. The initial two to three-acre
fenced preserve around
less than 0.5 acre about two years after completion of the
mall, which may result in loss or degradation of the cave
As part of mitigation for the taking as outlined in
their Habitat Conservation Plan, Melvin Simon and
Associates, Inc., acquired a total of 232 acres of preserve
land in three separate areas known to support four caves
containing Rhadine persephone (Rolling Rock and Testudo
Tube caves) and Texella reyesi (Red Crevice and
Thor caves). Three of the caves occur in Williamson
Parks and Wildlife Department is the management authority
for the LakeLine HCP.
Other mitigation measures in the LakeLine HCP include
a 10-year monitoring program of certain environmental
conditions (such as temperature, humidity, air movements,
and rainfall) and karst fauna (including species,
abundance, activity and location within the cave) for
years before and 5 years after mall completion, as well as
during construction. The purpose is to determine the
impacts of mall development on the cave ecosystem and the
listed species. Commensurate five-year studies of
environmental conditions and karst fauna will be done in
Testudo Tube and Temples of Thor Caves to serve as control
sites to the
food preferences, foraging range, and distribution of cave
crickets and daddy longlegs harvestmen at the above three
caves and fire ant control at all five sites. A karst
ecosystem exhibit for public education will be displayed
within the LakeLine Mall development project (Horizon
Environmental Services, Inc., 1991b).
1992c-e) initiated the
studies in May 1991 and began investigations of Testudo
Tube and Temples of Thor caves in May 1992. Monthly
ecological monitoring visits to these caves provide
information on temperature, humidity, air movements,
nutrient inputs, fire ants, and the distribution of
numerous species in the cave, but may not provide much data
on life histories and other aspects of the listed species’
biology. The cave cricket/daddy longlegs study is
providing data on the foraging behavior and
spatial/temporal distributions of these species, which feed
above ground at night. The cave cricket study will help
determine the surface area around the caves needed to
sustain these species. A major goal of this research is to
determine whether the karst invertebrate community in
the shopping mall and to assist in making preserve
recommendations for other caves.
In addition to the mitigation outlined above and prior
to the development of the HCP, Melvin Simon and
Associates, Inc. funded research designed to help determine
the extent to which karst fauna occur in the interstitial
spaces at the LakeLine Mall site. Six bore-holes were
drilled into the bedrock near a cluster of surface karst
features. Five-foot sections of 4-inch PVC pipe were
installed in each borehole. To prevent surface material
from entering the boreholes, approximately 2 feet of pipe
protruded above the surface, and the edges around each pipe
were sealed with rocks and dirt. Each pipe was then sealed
to prevent moisture loss.
Pitfall traps containing a variety of baits, including
moldy blue cheese, banana, peanut butter, and yeast were
placed inside each borehole to attract karst fauna. This
method was successful in trapping Rhadine persephone in one
borehole. No troglobites were found in the other five.
The baits do not attract many species, particularly more
sedentary predatory species such as Neoleptoneta myopica
and the Texella species. Baits may attract fire ants, as
may the surface disturbance generated during the drilling
Regional Habitat Conservation Plan (HCP): The City of
although specific preserve boundaries for the karst
features have not been determined at this time. Individual
applications for 10(a) (1) (b) permits and associated HCP’s
should contribute to achieving recovery plan goals,
particularly in setting aside cave preserves.
Security measures: To control access to caves where
unauthorized human visitation and vandalism present a
serious threat to the karst ecosystems and possible injury
to humans, cave gates have been installed at some cave
entrances. Caves where gates have been installed to date
include Tooth, Gallifer, Kretschmarr, Kretschmarr
Salamander, LakeLine, and Sore-ped caves. Most of these
cave gates consist of a locked door fashioned from an open
steel grid to prevent unauthorized entry. Cave gates
should be designed to permit normal air flow, water
infiltration, and nutrient input. Since some cave gates
have been known to filter out important nutrient sources,
particularly larger animals such as raccoons, they should
be closely monitored and rectified should such problems
One alternative to gating that may pose less
interference with the nutrient regime and other
environmental factors (such as air and water movement) is
the installation of a high fence around a cave preserve.
Chain-link fences have been installed around Kretschmarr
are subject to vandalism, they may require frequent
surveillance. The effectiveness of gating and fencing and
their effects on the karst ecosystems should be closely
monitored. Other alternatives to protecting caves from
human visitation and vandalism, such as public education
and routine site patrols, should also be explored.
Other conservation measures: In late 1988, the USFWS, in
conjunction with two groups of developers, sponsored a
hydrogeologic study of a cave cluster located to the
northwest of the RM 2222 and RM 620 intersection to aid in
determining measures to protect this cluster, which
supports six of the listed species. The project, conducted
by Veni & Associates (1988a), provided guidelines for
protecting the caves based largely on hydrogeologic
factors, but did not involve biological investigations.
The study was used by a group of experts assembled by USFWS
to prepare guidelines for the protection of the cave
cluster. The group’s guidelines were used in discussions
between USFWS and the developers about protecting the caves
and cave fauna.
Local caving organizations have been instrumental in
locating and monitoring karst features and maintaining a
database of their findings. Several of these organizations
have published reports of their findings and made
conservation and management recommendations that are useful
to the USFWS. Other contributions made by local cavers
include the removal of trash from cave openings and the
detection of contaminant spills.
The entrances to
been under the stewardship of the Texas System of Natural
Laboratories (TSNL) on behalf of the owners since about
1970. This resulted in the discovery of several more caves
containing troglobites. A small area (about 0.6 acres)
around Tooth Cave and a total of about six acres
Jollyville Plateau were deeded by the owner to the TSNL in
1990. However, the preserves around these caves are not
sufficient to counter nutrient depletion and prevent
pollution should the surrounding areas be developed. The
entire area is now infested with fire ants. Furthermore,
some of these caves are under temporary deed to TSNL and
may be sold at the owners’ discretion.
F. Recovery Strategy
This recovery plan is designed to outline steps for
long-term protection of the listed invertebrate species,
including restoration and enhancement of the habitat where
necessary. The recovery criteria state that each species
will be considered for downlisting from endangered to
threatened when three karst fauna areas (if at least three
exist) within each karst fauna region in each species’
range are protected in perpetuity (see Section II.A for a
more detailed delineation of the criteria).
The “karst fauna regions” depicted in Figure 2 of this
plan are adapted from the karst fauna areas delineated in
Veni & Associates’ 1992 report (see discussion in Section
I.B) . These regions are delineated based on geologic
continuity, hydrology, and the distribution of 38 rare
troglobitic species. Each karst fauna region can be
further subdivided into karst fauna areas. For the
purposes of this plan, a “karst fauna area” is an area
known to support one or more locations of a listed species
and is distinct in that it acts as a system that is
separated from other karst fauna areas by geologic and
hydrologic features and/or processes that create barriers
to the movement of water, contaminants, and troglobitic
fauna. Karst fauna areas should be far enough apart so
that if a catastrophic event (for example, contamination of
the water supply, flooding, disease) were to destroy one of
the areas and/or the species in it, that event would not
likely destroy any other area occupied by that species.
As troglobitic populations become increasingly
isolated due to hydrogeologic processes, subsequent
speciation among the isolated populations may occur. The
recovery criteria are designed to allow these natural
evolutionary processes to continue for each species. The
recovery criteria aim at protecting populations and
preserving genetic diversity across each species’ range.
Full implementation of the recovery criteria should
protect against catastrophic loss of the listed species.
Because karst ecosystems can never be recreated once they
are destroyed, an adequate number of karst fauna areas per
karst fauna region should be protected in perpetuity to
ensure the continued survival and conservation of each
species. Ideally, at least three karst fauna areas per
karst fauna region should be protected to provide a margin
of safety against extinction if one or more protected areas
are lost due to an unanticipated catastrophic event. This
is particularly important for karst species since their
habitat can not be recreated. If a given species only
occurs in two karst fauna areas, that species would still
be considered for downlisting provided both areas were
adequately protected. Species whose entire range consists
of only one karst fauna area (should one area be destroyed)
will not be considered for downlisting. If a species
occupies several karst fauna regions (such as Texella
reyesi), but one or more of those karst fauna regions
contains less than three karst fauna areas, then all karst
fauna areas within that region must be protected in order
to meet the recovery objective.
The first step in recovering these species is to
identify the karst fauna areas targeted for recovery.
According to the recovery criteria, all localities
inhabited by four of the listed species (Neoleptoneta
myopica, Tartarocreagris texana, Texamaurops reddelli, and
Batrisodes texanus) should be provided long-term protection
prior to consideration for downlisting. Three of the
listed species, Texella reddelli, Texella reyesi, and
Rhadine persephone, occupy karst fauna regions that contain
more than three karst fauna areas. Table 3 identifies the
karst fauna regions in which each species occurs, the
approximate number of karst fauna areas inhabited by each
species, and the number of karst fauna areas that should be
protected, based on the recovery criteria for downlisting
and current knowledge of the species’ distributions
(figures 3-9). Continuing surveys for caves and karst
invertebrates may result in an increase in the number of
karst fauna areas occupied by some species.
In selecting karst fauna areas to be targeted for
recovery, priority should be given to those areas that
exhibit high species diversity and contain other rare or
listed species. This ecosystem-based approach to choosing
karst fauna areas for preservation should consider both the
listed species and other endemic species and may prevent
the need for listing additional species in the future.
Numerous rare species inhabit the same karst terrains in
Travis and Williamson counties. For example,
contains at least 32 rare karst species, 25 of which are
not federally-listed and some of which are undescribed
(Elliott 1992a). Many of those rare species were
taxonomically described in 1992 and some may become
candidates for the endangered species list, especially
those found in urbanizing areas. Therefore, judicious
selection of karst areas for preservation will aid in the
recovery of the listed species, help protect other
important elements of the karst ecosystem in Travis and
Williamson counties, and possibly prevent the need to list
other species in the future.
Within each karst fauna region, karst fauna areas that
are targeted for recovery should be located as far apart as
possible, to protect against catastrophic loss and to
preserve genetic diversity within each species. Other
factors to consider when selecting karst fauna areas
include ability to ensure long-term protection, current
level of habitat disturbance, past and present land use,
presence of other rare or candidate species, ease of
protection (landowner cooperation), and, where applicable,
importance to the regional groundwater system.
Where the listed species’ ranges overlap, particularly
on the Jollyville Plateau, more than one of the species may
occur in a given karst fauna area. For example, six of the
seven species occur in the Jollyville Plateau karst fauna
region, and three of the species’ entire ranges are in the
vicinity of the RM 2222/RM 620 intersection.
Two areas within the Jollyville Plateau karst fauna
region that are already known to be very important to the
survival and recovery of several of the listed species
represent two distinct karst fauna areas and should be
targeted for protection. One of these areas, the Tooth
Cave karst fauna area, harbors six of the seven listed
species and one of the most diverse cave biotas in the
Cave karst fauna area, contains five of the listed species.
Preservation of these two karst fauna areas would protect
100% of the range of two of the listed invertebrates
(Texamaurops reddelli and Tartarocreagris texana) and 67%
of the range of Neoleptoneta myopica. A suggested karst
fauna area for the
The second major step in recovery is to determine the
appropriate size and configuration of each of the karst
fauna areas targeted for recovery. To be considered
“protected”, a karst fauna area should contain a large
enough expanse of contiguous karst and surface area to
maintain the integrity of the karst ecosystem on which each
species depends. The size and configuration of each karst
fauna area should be adequate to maintain moist, humid
conditions, air flow, and stable temperatures in the air-
filled voids; maintain an adequate nutrient supply; prevent
contamination of surface and groundwater entering the
ecosystem; prevent or control the invasion of exotic
species, such as fire ants; and allow for movement of the
karst fauna and nutrients through the interstitium between
Several factors should be considered in determining
the size and configuration of karst fauna areas, including
the pattern and direction of groundwater movement,
direction and area of surface and subsurface drainage,
preservation of the surface community above and surrounding
the cave, and the presence of other caves or karst
features. In general, land bounded by the contour interval
at the cave floor is the area within which contaminants
moving over the surface or through the karst could move
toward the cave. Outside this contour, contaminants would
move away from the cave. A hydrogeologic investigation may
be useful in determining the surface and subsurface
drainage basin of the karst ecosystem, local recharge
areas, and direction of groundwater movement. This
information would be used to determine the area necessary
to protect the karst fauna area’s water supply. The amount
of surface area necessary to maintain the ecological
processes of the karst ecosystem should also be considered
and may be larger than the surface drainage area of the
cave. Other nearby karst features, which may affect the
moisture, air flow, temperature, and nutrient regimes and
allow movement of karst fauna through the interstitium,
should be included in each karst fauna area. Major sources
of nutrient input and areas necessary to sustain these
sources should be considered. Recent research as part of
the LakeLine Mall HCP may provide some information on the
importance of the surface area surrounding karst features
in providing nutrients to the cave ecosystem. Wherever
possible, karst fauna areas should connect to larger
undeveloped lands that are not slated for future
development, in order to ensure adequate nutrient flow into
the karst ecosystem and to help combat the fire ant threat.
Setting aside large preserves may help to control fire
ants. Porter et al. (1991) state that control of fire ants
in large areas (>5 hectares) (12 acres) may be more
effective than in smaller areas since multiple queen fire
ant colonies reproduce primarily by “budding” (whereby
queens and workers branch off from the main colony and form
new sister colonies) . Budding is a relatively slow
process, and fire ants may not as quickly reinvade areas
where they have, been eliminated with this method. Native
ant communities may also require large, undisturbed areas
to help them combat the fire ant threat.
Research in some areas, including the fire ant’s
native range, indicates that fire ants are associated with
open habitats disturbed as a result of human activity (such
as old fields, lawns, roadsides, ponds, and other open,
sunny habitats) but are absent or rare in late succession
or climax communities such as mature forest (Tschinkel
1986) . Although this association is not apparent in all
areas, especially in central
1991), maintaining native vegetation communities may help
sustain native ant populations and further deter fire ant
infestations. Chemical control methods have some
effectiveness in controlling fire ants, but the effect of
these agents on non-target species (including the listed
invertebrates) is unclear and, if used indiscriminately,
may also eliminate native ant populations. Ideally,
intensive fire ant control should be implemented along
disturbed areas on the periphery of large preserves. This
type of fire ant control, combined with safer but more
labor intensive methods (such as hot water applied mound-
by-mound) in the vicinity of cave entrances, should help
sustain the native ant fauna and reduce the need to
implement intensive control within the preserve.
Due to the multiplicity of factors to consider when
determining the size and configuration of the karst fauna
areas, the design of each karst fauna area will be site-
specific. Although many factors (such as the species’
ecological requirements, distribution in the interstitium,
and the amount of surface area necessary to sustain
nutrient flow) are unknown, the amount of time and
financial expense to acquire this knowledge would preclude
achieving the recovery objective if karst fauna area
protection were delayed pending additional research in
these areas. To compensate for this lack of knowledge,
delineation of the karst fauna areas should be based on
protecting the integrity of the karst terrain supporting
the listed species and a conservative interpretation of the
available biological and hydrogeological information.
Another step needed to accomplish recovery is to
provide long-term protection for the targeted karst fauna
areas. Methods could include land acquisition,
conservation easements, and cooperative agreements with
private landowners and public entities.
Implementation of appropriate conservation and
management measures for each targeted karst fauna area is
also needed for recovery. This may include control of fire
ants and other threats; management of surface plant and
animal communities; maintaining surface and groundwater
quality and quantity; preventing vandalism, dumping, and
unauthorized human visitation; and other actions deemed
necessary. Additional studies will be necessary to monitor
the effects of each management program, refine management
techniques as appropriate, and determine any other steps
necessary to fully recover the species.
Regardless of whether a listed species occurs in a
karst ecosystem that is in or outside of a karst fauna area
targeted for protection, the listed species are still
protected under the Endangered Species Act (Act) unless
authorization for incidental “take” has been obtained under
Section 7 or Section 10 of the Act.
A. OBJECTIVE AND CRITERIA <snip>
B. RECOVERY OUTLINE <snip>
C. NARRATIVE OUTLINE FOR RECOVERY ACTIONS <snip>
D.D. REFERENCES CITED
Barr, T.C., Jr. 1968. Cave ecology and the evolution of
troglobites. Evolutionary Biol., 2: 35-102.
Barr, T.C., Jr. 1974a. Revision of Rhadine LeConte
(Coleoptera, Carabidae). I. The subterranean group.
Amer. Mus. Novitates, No. 2539. 30 pp.
Barr, T.C., Jr. 1974b. The eyeless beetles of the genus
Arianops Brendel (Coleoptera, Pselaphidae) . Bull.
Amer. Mus. Nat. Hist., 154: 1-52.
Barr, T.C., Jr. and H.R. Steeves, Jr. 1963. Texamaurops,
a new genus of pselaphids from caves in
(Coleoptera: Pselaphidae). Coleopterists’ Bull., 17:
Biological Advisory Team (BAT) 1990. Comprehensive
report of the Biological Advisory Team.
Brignoli, P.M. 1972. Some cavernicolous spiders from
Sci. Cult., 171(1): 129-155.
Bull, E., and R.W. Mitchell. 1972. Temperature and
relative humidity responses of two
millipedes, Cambala speobia (Cambalida: Cambalidae)
and Speodesmus bicornourus (Polydesmida:
Vanhoeffeniidae). Southwestern Nat., 4: 365-393.
(Coleoptera). Speleol. Monogr., 3.
Christiansen, K., and D. Culver. 1969. Geographical
variation and evolution in Pseudosinella violenta
(Folsum) . Evolution, 23(4): 602-621.
Curcic, B.P.M. 1984. A revision of some North American
species of Microcreagris Balzan, 1982. (Arachnida:
Pseudoscorpiones: Neobisiidae). Bull. British
Arachnol. Soc. 6: 149-166.
Curcic, B.P.M. 1989. Further revision of some North
American false scorpions originally assigned to
Microcreagris Balzan (Pseudoscorpiones, Neobisiidae).
J. Arachnol. 17: 351-362.
Elliott, W.R. 1976. Morphometrics and evolution of
Polydesmida). Ph.D. dissertation, Texas Tech Univ.
W.R. 1978a. The cave fauna of
in Fieseler, R.G., J. Jasek, and M. Jasek (eds.), An
introduction to the caves of
Soc. Convention Guidebook, 19 pp.
Elliott, W.R. 1978b. The New Melones cave harvestman
transplant. Report to
Elliott, W.R. 1991a. Preliminary ecological monitoring at
Elliott, W.R. 1991b. Ecological monitoring at LakeLine
Elliott, W.R. 1991c. Ecological monitoring at LakeLine
Elliott, W.R. 1991d. Ecological monitoring at LakeLine
Elliott, W.R. 1991e. Ecological monitoring at LakeLine
Cave and Testudo Tube,
Melvin Simon & Associates,
Elliott, W.R. 1991f. Ecological monitoring at LakeLine
Cave, 30 October &
Melvin Simon & Associates,
Elliott, W.R. 1992a. Fire ants and endangered cave
invertebrates: A control and ecological study. Draft
Elliott, W.R. 1992b. Ecological studies of three caves in
Elliott, W.R. 1992c. Ecological studies of three caves in
Elliott, W.R. 1992d. Ecological studies of three caves in
Elliott, W.R. 1992e. Ecological studies of three caves in
fauna conservation in
Elliott, W.R., and R.W. Mitchell. 1973. Temperature
preference responses of some aquatic, cave-adapted
Elliott, W.R., and J.R. Reddell. 1989. The status and
range of five endangered arthropods from caves in the
Habitat Conservation Plan. 100 pp.
Gertsch, W.J. 1974. The spider family Leptonetidae in
Goodnight, C.J., and M.L. Goodnight. 1942. New
Phalangodidae (Phalangida) from the
Amer. Mus. Novitates, 1188: 1-18.
Goodnight, C.J., and M.L. Goodnight. 1967. Opilionida
Mus. Novitates, No. 2301. 8 pp.
Holsinger, J.R. 1967. Systematics, speciation, and
distribution of the subterranean amphipod genus
Stygonectes (Gammaridae). Bull.
259. 176 pp.
Horizon Environmental Services, Inc. 1991a. Karst
invertebrate survey of the LakeLine Mall site,
& Associates, Inc.
Horizon Environmental Services, Inc. 1991b. Habitat
Conservation Plan for LakeLine Mall, Williamson
Howarth, F.G. 1983. Ecology of cave arthropods. Ann.
Rev. Entomol., 28: 365-389.
Maguire, B., Jr. 1960. Monodella texana n.sp., an
extension of the crustacean order Thermosbaenacea to
May, R.M. 1992. How many species inhabit the Earth? Sci.
American, 267: 42-48.
Mitchell, R.W. 1968a. Distribution and dispersion of the
troglobitic carabid beetle Rhadine subterranea. Intl.
J. Speleol., 3: 271-288.
Mitchell, R.W. 1968b. Food and feeding habits of the
troglobitic carabid beetle Rhadine subterranea. Intl.
J. Speleol., 3: 249-270.
Mitchell, R.W. 1968c. Preference responses and tolerances
of the troglobitic carabid beetle, Rhadine
subterranea. Intl. J. Speleol., 3: 289-304.
Mitchell, R.W., and J.R. Reddell. 1971. The invertebrate
Jr., and B.H. Slaughter, (eds.) Natural History of
Muchmore, W.B. 1969. New species and records of
cavernicolous pseudoscorpions of the genus
Microcreagris (Arachnida, Chelonethida, Neobisiidae,
Ideobisiinae). Amer. Mus. Novitates, No. 2932. 21
Muchmore, W.B. 1992. Cavernicolous pseudoscorpions from
Speleol. Monogr., 3.
Park, O. 1960. Cavernicolous pselaphid beetles of the
Platnick, N.I. 1986. On the tibial and patellar glands,
relationships, and American genera of the spider
family Leptonetidae (Arachnida, Araneae). Amer. Mus.
Novit., 2855. 16 pp.
Porter, S.D., B. Van Eimeren, and L.E. Gilbert. 1988.
Invasion of red imported fire ants (Hymenoptera:
Formicidae): Microgeography of competitive
replacement. Ann. Ent. Soc of
Porter, S.D., A. Bhatkar, R. Mulder, S.B. Vinson, and D.J.
Clair. 1991. Distribution and density of polygyne
fire ants (Hymenoptera: Formicidae) in
Econom. Entomol. (84)3: 866-874.
Porter, S.D. and D.A. Savignano. 1990. Invasion of
polygyne fire ants decimates native ants and disrupts
arthropod community. Ecology 71(6): 2095-2106.
Reddell, J.R. 1965. A checklist of the cave fauna of
Reddell, J.R. 1966. A checklist of the cave fauna of
Reddell, J.R. 1967. A checklist of the cave fauna of
Reddell, J.R. 1970a. A checklist of the cave fauna of
(exclusive of Insecta).
Reddell, J.R. 1970b. A checklist of the cave fauna of
Sci., 22: 47-65.
Reddell, J.R. 1970c. A checklist of the cave fauna of
J. Sci., 21: 139-158.
45, Segments 3 and 4, Environmental Impact on Cave
Fauna. Report prepared for Texas Department of
Highways and Public Transportation.
Reddell, J.R. 1991. Further study of the status and range
of endangered arthropods from caves in
Wildlife Service. iv + 178 pp.
Reddell, J.R., and W.R. Elliott. 1991. Distribution of
endangered karst invertebrates in the Georgetown Area,
Reddell, J.R., and R. Finch. 1963. The caves of
Ubick, D., and T.S. Briggs. 1992. The harvestman family
Phalangodidae. 3. Revision of Texella Goodnight and
Goodnight (Opiliones Laniatores). Speleol. Monogr.,
(Vireo atricapillus) Recovery Plan.
pp. vi + 74.
Warbler (Dendroica chrysoparia) Recovery Plan.
threatened wildlife and plants:
beetle (Batrisodes texanus) and the
harvestman (Texella reyesi) determined to be
endangered. FR 58 43818-43820.
threatened wildlife and plants; 90-day finding on a
petition to delist seven
Veni & Associates. 1988a. Hydrogeologic investigation of
the Jollyville Plateau karst, Travis County, Texas.
Report prepared for Parke Investors Ltd., 620
Investors Ltd., and
Veni & Associates. 1988b. Hydrogeologic and biologic
Report prepared for Murfee Engineering Co., Austin,
Veni & Associates. 1992. Geologic controls on cave
development and the distribution of cave fauna in the
Wildlife Service. v + 77 pp.
E.C., and A.T. Jackson. 1948.
pp. 62-64 in The Caves
Vinson, S.B. and A.A. Sorensen. 1986. Imported fire ants:
Life history and impact. Texas Department of
III. RECOVERY PLAN IMPLEMENTATION SCHEDULE <snip>
Appendix A. Glossary
Aedeagus - In male insects, the mating organ which is
everted from the posterior.
Apical - At the tip of a structure (see proximal).
Apophysis - In arthropods, a chitinous ingrowth of the
exoskeleton for muscle insertion.
Attenuated — Elongated, especially appendages, antennae,
Biospeleology — The study of cave life and its relations to
the surface and subsurface environment.
Book lungs — Primitive breathing organs found in lower
arachnids such as scorpions and some spiders.
Borehole - In this work, a vertical hole drilled in bedrock
for sampling karst fauna. Referred to as “corehole” in
Carabid - Ground beetle, including Rhadine Persephone.
Carapace — The upper exoskeleton of the thorax of an
Carinate — Having a carina, or keel, running lengthwise
along an appendage.
Cavernicole — A species occurring only in caves, not
necessarily eyeless and depigmented.
Chelae — The pincerlike claw of a scorpion’s or
pseudoscorpion’ s pedipalp.
Chelicerae — The first pair of appendages in an arachnid in
front of the mouth, adapted for grasping and cutting up
food; usually claw-like.
Collembolans (springtails) - Minute insects that have a
forked structure on the abdomen that enables them to jump.
Usually common and abundant. Feed on plant material, fungi,
bacteria, arthropod feces, pollen, algae, and/or other food
Dark zone — The permanently dark zone of the deep cave
environment where no light penetrates, as opposed to
DNA (Deoxyribonucleic acid) - the substance that carries
the cell’s genetic code in the nucleus.
Elytra — In beetles, the hardened front wings which serve
as covers to protect the delicate hind wings when the
insect is not flying.
Endemism, endemic — Indigenous or native to a restricted
Epigean — Living on the surface, as opposed to living below
the surface (hypogean).
Eye mound — In harvestmen, the conical projection on the
dorsum (upper side) of the body bearing the two eyes.
Facet — An individual visual organ in the compound eye of
Feebly arcuate - slightly arched.
Femur — The third joint of an arachnid appendage.
Foveae - Small pits on the surface of the arthropod body.
Genital operculum - In harvestmen, a flap covering the
Holotype — The primary type specimen selected as
representative of a species by a taxonomist who describes
the species. A holotype must be housed in a scientific
collection that is available for study by qualified
Hydrogeology — The study of water dynamics in relation to
geology, especially groundwater.
Infragroup - A collection of species within a subgroup (see
below) that share similar physical and/or genetic traits.
The smallest division in a hierarchical system of grouping
species based on degrees of relatedness.
Karst — A terrain characterized by landforms and subsurface
features, such as sinkholes and caves, that are produced by
solution of bedrock (usually limestone or gypsum) . Karst
areas commonly have few surface streams; most water moves
through cavernous openings underground.
Metathoracic wings — The hind wings of an insect.
Metatibial pencil of setae — A small brush of setae (hairs)
found on the tibia of the third leg.
Microarthropod — A tiny arthropod, such as a springtail,
Monophyletic assemblage — A group of species that has
descended from a common ancestor.
Niche - The role a species plays within its community or
Obsolescent eyes — Eyes that are nearly absent; only a
small remnant may remain.
Ocular knobs - Eye remnants (bumps) that would normally
bear a compound eye.
Ovipositor cuticle — The surface of the female ovipositor
(an organ for laying eggs in the soil).
Palpal — Pertaining to the pedipalps.
Parastylar - On either side of the stylus, part of the
Paratopotype — A type specimen selected by a taxonomist as
a representative example of a species and which comes from
the original type locality which he/she designates.
Paratype — A secondary type specimen selected by a
taxonomist to represent a species being described; not
necessarily of the same sex as the holotype or from the
Pedipalps — The second pair of appendages in arachnids, the
bases of which provide a jaw-like function; the pedipalps
provide a grasping or pinching function for handling food.
Phalangodid - Daddy longlegs harvestman, including Texella
reddelli and Texella reyesi.
Polymorphic — Exhibiting much physical variation among
Postopercular process — In some harvestmen, a projection
posterior to the genital operculum.
Pronotum — In insects, the dorsal (upper) side of the
anterior (front) part of the thorax. In Rhadine beetles,
the pronotum is elongated like a neck.
Protuberance - A knob or prominence.
Proximal — At the base of a structure (see apical)
Pselaphid - Short winged mold beetle, including Texamaurops
reddelli and Batrisodes texanus
Psocid - Small, soft-bodied insect, usually less than 6 mm
Punctulate - Pitted.
Retrolateral — On the backside of an appendage.
Robust - Relatively thick-bodied, compared to others in the
same group (opposite of slender, below)
Rugosity — A rough or scaly quality to the exoskeleton.
Scute — An exoskeletal plate on the dorsal (upper) side of
a harvestman’s body.
Setae - Hairs.
Slender - Relatively thin-bodied, compared to others in the
same group (opposite of robust, above)
Spatulate — Flattened like a spatula.
Species group - A collection of species that share similar
physical and/or genetic traits. The highest division in a
hierarchical system of grouping species based on degrees of
Spermathecae — Sacs used for the storage of sperm in female
pseudoscorpions and other invertebrates.
Stylus — The long, thin part of a harvestman’s penis.
Subcontiguous — Not quite touching.
Subgroup - A collection of species within a species group
(see above) that share similar physical and/or genetic
traits. An intermediate division in a hierarchical system
of grouping species based on degrees of relatedness.
Speleology— The scientific study and exploration of caves.
Sympatric — Two species within the same genus occurring in
the same place.
Tarsomeres - The segments at the end of an arthropod leg.
Taxonomy — The classification and nomenclature of living
things, also referred to as “systematics”. A taxonomist
publishes species descriptions and/or revisions in
scientific journals, based on studies of the anatomy,
biology, or genetics of a certain taxon (group).
Tergal chaetotaxy — The pattern of setae (hair-like
structures) on the dorsal (upper) plates of an arthropod.
Tergite — The dorsal (upper) plate of an arthropod’s
Tibia — The fourth joint of an arthropod leg.
Transverse impression - A crease that runs from side to
Trochanter - In arthropods, the second joint of the leg.
Troglobite — An animal that completes its lifecycle and
spends its entire life in openings underground (such as
caves) usually with small or absent eyes, attenuated
appendages, and other adaptations to the subsurface
Troglomorphy, troglomorphism, troglomophic — The physical
characteristics of a troglobite, typified by eyelessness,
attenuated appendages, depigmentation, delicate integument
or exoskeleton, and greater development of some sensory
Troglophile — An animal that spends most of its life in
openings underground, but may also be found above ground;
not usually eyeless or depigmented.
Trogloxene — A cave-dwelling animal that leaves the cave on
a regular basis to feed, such as bats and cave crickets.
Tubercle - A small, rounded nodule or mound.
Twilight zone — The cave zone in which light from the
entrance is still visible.
Vestigial — Having only a vestige, or a remnant, of a
Appendix B. Individuals and Agencies Providing Comments on
the Draft Recovery Plan for Endangered Karst Invertebrates
in Travis and
Appendix C. Simmary of Comments Received on the Draft
Recovery Plan for Endangered Karst Invertebrates in Travis