(DRAFT) - Taxonomy
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
TAXONOMY
NAME - LIZARD, NIGHT, ISLAND
OTHER COMMON NAMES - LIZARD, NIGHT, ISLAND; LIZARD, SPECTACLED, ISLAND; LIZARD and NIGHT
ELEMENT CODE -
CATEGORY - Reptiles
PHYLUM AND SUBPHYLUM - CHORDATA,
CLASS AND SUBCLASS - REPTILIA,
ORDER AND SUBORDER - SQUAMATA,
FAMILY AND SUBFAMILY - XANTUSIIDAE,
GENUS AND SUBGENUS - XANTUSIA,
SPECIES AND SSP - RIVERSIANA,
SCIENTIFIC NAME - XANTUSIA RIVERSIANA
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Island Night Lizard
Xantusia riversiana Cope, 1883
KINGDOM: Animal GROUP: Reptile
PHYLUM: Chordata CLASS: Reptilia
ORDER: Squamata FAMILY: Xantusiidae
The island night lizard, Xantusia riversiana, Cope (01), is the
largest member of the genus, Xantusia; adult body size is 6.5-10.9 cm
snout-vent length (02). It can be distinguished from other species of
Xantusia by the presence of two rows of supraocular scales, 16
longitudinal rows of ventral scales, and the lack of pretemporal
scales. Other Xantusia species have a single row of supraoculars,
12-14 rows of ventrals, and pretemporals (03,04). There is
considerable variation in color pattern among island night lizards.
Individuals may be a uniform tan color, or spotted with dark brown on
light brown or grey background. Spotting can range from fine grained
to coarse reticulations, and some individuals have light dorsolateral
stripes (04,05). Photographs illustrating pattern variation in
X. riversiana can be found in reference 05. Males have slightly
larger femoral pores (04) and larger lateral post-anal scales (34),
however these characters are intergrading, and it is often difficult
Taxonomy - 1 (DRAFT) - Taxonomy
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
to reliably make sex determination from external characters.
Questions about the taxonomic status of X. riversiana have
concerned whether the species is sufficiently distinct from other
members of the genus, Xantusia, to warrent placing it in a unique
genus. Savage (03, 06) erected the monotypic genus, Klauberina, for
the island night lizard based largely on differences in scutellation
and osteology. Bezy (07) returned the species to the genus, Xantusia,
arguing from chromosomal, morphological, and biogeographic evidence
that the island night lizard and other species of Xantusia are more
similar to each other than to any other of the Xantusiidae.
Reference collections of Xantusia riversiana are deposited in the
Los Angeles County Museum of Natural History and in the San Diego
Museum of Natural History.
This lizard is also known as the island spectacled lizard, or
simply the night lizard.
Taxonomy - 2 (DRAFT) - Status
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
STATUS
Coded Status
T: Federal Threatened
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The island night lizard (Xantusia riversiana) has been
designated a Threatened species pursuant to the Endangered Species
Act of 1973 (50 CFR 17.11; P.L. 93-205, 87 Stat. 884; 16 U.S.C.
1531-1540), as amended. The species has this status wherever found
including the State of California. The present known range includes
Santa Barbara, San Nicholas, and San Clemente Islands, California.
This species is protected by the Lacey Act (P.L. 97-79, as
amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to import,
export, transport, sell, receive, acquire, or purchase any wild
animal (alive or dead including parts, products, eggs, or offspring):
(1) in interstate or foreign commerce if taken, possessed,
transported or sold in violation of any State law or
regulation; or
(2) if taken or possessed in violation of any U.S. law,
treaty, or regulation or in violation of Indian tribal law.
It is also unlawful to possess any wild animal (alive or dead
including parts, products, eggs, and offspring) within the U.S.
territorial or special maritime jurisdiction (as defined in
18 U.S.C. 7) that is taken, possessed, transported, or sold in
violation of any State law or regulation, foreign law, or Indian
tribal law.
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
DOD -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public land under their control. Also responsible for
management/recovery on Department of Defense lands.
NPS -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for conservation (Nat. Park System Organic Act - 16
U.S.C. 1, 2-3)/management/recovery on National Park
Service lands. Taking, possessing, or disturbing of
Federally listed species is prohibited on NPS lands
(36 CFR 2.1, 2.2, and 2.3).
All Federal agencies have responsibility to ensure that any
action authorized, funded, or carried out by that agency is not likely
Status - 1 (DRAFT) - Status
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
to jeopardize the continued existence of the species or result in the
destruction or adverse modification of Critical Habitat (50 CFR 402),
and to utilize their authorities to carry out programs for the
conservation of the species.
STATE STATUSES AND LAWS:
STATE: California
DESIGNATED STATUS: Protected
ADMINISTRATIVE AGENCY: Department of Fish and Game
STATE STATUTE: Fish and Game Code (FGC) Subsection 2000, 2002;
FGC Section 2013.
The California Environmental Quality Act (PRC 2100 et seq.)
recognizes Federally listed Threatened and Endangered species as among
those species requiring that environmental impact assessments be made
for actions that may detrimentally affect them. See: Guidlines for
Implementation of the California Environmental Quality Act, California
Administrative Code, Chapter 3, Section 15380.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
The island night lizard is listed in the IUCN Red Data Book.
ECONOMIC STATUSES:
None.
76/06/01:41 FR 22073/22075 - Proposed rule, listing
77/08/11:42 FR 40682/40685 - Final rule, listed as Threatened
82/09/27:47 FR 42387/42388 - Five year review
87/07/07:52 FR 25523/25528 - Notice of review
Status - 2 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
LAND USE -
Mixed Urban or Built-up Land
Herbaceous Rangeland
Shrub and Brush Rangeland
Mixed Rangeland
Bare Exposed Rock
Transitional Areas
COMMENTS ON HABITAT ASSOCIATIONS -
Like other members of the lizard family, Xantusiidae, the island
night lizard is intensely secretive and requires dense shelter. This
may include a wide variety of cover ranging from rock crevices and
stones on the ground to dense patches of vegetation. Wooden boards
and other large pieces of debris also provide good retreats. Dense
cover is important in protecting the lizards from predation and
allowing them to regulate body temperature. Lizards control their
body temperatures by moving through microhabitats and seeking sites
with compatible environmental temperatures. X. riversiana
thermoregulates over a lower range of temperatures than most lizards
and will not tolerate temperatures above 40 degrees C (08,14). Thus
the lizards must be able to retreat from extreme ground surface
temperatures on hot days. The best cover for effective temperature
regulation is thick vegetation which intercepts solar radiation and
buffers the ground surface from temperature extremes. Alternatively
effective shelter is provided by massive rocks whose recesses will not
overheat on hot days. The most favorable habitat conditions for X.
riversiana appear to be a thick, low-lying vegetation structure
growing on rocky soil. Under these conditions shafts of sunlight
penetrate to the ground surface produce a mosaic of thermal
microenvironments (08). The lizards can move about to select a proper
thermal environment and find food with minimal risk of exposing
themselves to predators.
X. riversiana can be found in all habitats of the islands which
have suitable shelter. These include maritime desert scrub, cactus
(Opuntia littoralis) scrub, and grasslands. The only habitat which
appears to be unsuitable is sand dunes. X. riversiana can be found in
greatest abundance in a near shore maritime desert scrub consisting of
low dense thickets of shrubs (Lycium californicum and Atriplex
semibaccata) and cacti (Opuntia littoralis and Bergerocactus emoryi)
with scattered rock outcrops. On San Clemente Island there are
extensive regions of favorable habitat, and the lizards are locally
abundant. In contrast, several observers have noted that X.
riversiana is relatively difficult to find on San Nicholas and Santa
Barbara Islands (09,36,34). San Nicholas Island is extensively eroded
and the native vegetation has been severely disturbed by earlier sheep
and goat ranching. Favorable habitat for X. riversiana appears to be
confined to limited stands of Opuntia cactus near the airfield, refuse
dumps, and piles of driftwood blown inland among desert scrub
vegetation along the shore (09,15). The situation on Santa Barbara
Island is sensitive because the island is small (2.6 square km), and
vegetation is sparse. Lycium californicum and Opuntia habitats have
been estimated to cover only 7% of the island (15). However, the
vegetative habitat appears to be stable in the recent past, and
lizard's populations do not appear to be declining (35).
Human use of San Clemente and San Nicholas Islands is associated
Habitat Associations - 1 with military operations (i.e., air fields, roads, buildings, missile
launch sites, and troop manuevers).
Habitat Associations - 2 (DRAFT) - Food Habits
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
FOOD HABITS
TROPHIC LEVEL -
OMNIVORE
LIFESTAGE FOOD FOOD PART
General Forb Leaves/Stems
General Forb Flowers/Fruit/Seed
General Evergreen Shrubs-Leaves/Twigs
General Evergreen Shrubs-Flowers/Fruit/Seed
General Crustaceans
General Cactus-Flowers/Fruit/Seed
General Arthropods
Food Habits - 1 (DRAFT) - Environment Associations
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Coastal Features: Rocky offshore islands
G Coastal Features: Vegetated offshore islands
G Terrestrial Features: Rock outcrops
G Terrestrial Features: Downed logs
Environment Associations - 1 (DRAFT) - Life History
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
LIFE HISTORY
FOOD HABITS:
Xantusia riversiana is a generalist in its food habits. Lizards
feed on both plants and arthropods, the former composing about 30% of
the diet. Arthropods consumed are beetles, crickets, moths,
caterpillars, ants, flies, spiders, silverfish, Collembola, wasps,
Hemiptera, Homoptera, Neuroptera, isopods, scorpions, and centipedes.
Plant material includes stems, flowers, seeds, and terminal leaves of
a variety of species, including Mesembryanthemum, and fruit of the
Cactus Opuntia littoralis. References for the diet of X. riversiana
are 04, 16, 17, 18, and 34.
HOME RANGE/TERRITORY:
The island night lizard is probably territorial, although little
direct information is available due to the secretive habits of this
lizard. Individuals are aggressive toward one another in captivity
and will inflict head bites on each other if confined closely
together. There is no published information on home range of this
species, however a current mark-recapture study (in progress) reveals
most recaptures are at the same shelter or within a few meters of the
original capture point. Sampling intervals in this study are 6 months
to 1 year; thus lizards appear to have very small home ranges (37).
PERIODICITY:
Xantusia riversiana are active and feed during all times of the
year, however, episodes of summer drought may curtail activity (34).
Daily activity patterns in Xantusid lizards are difficult to
determine. Because they are so secretive, these lizards are commonly
referred to as "night lizards", but maximum activity is, for the most
part, during the day (19,20,21,22,23,24,25,08,14). Xantusia henshawi
and X. vigilis have been observed abroad at night during the spring
and summer months (14,23,24,26); night time activity in this family of
lizards may be related to breeding biology, and daytime activity may
be necessary for thermoregulation and foraging (23). X. riversiana
probably behaves similarly although its activity patterns have not
been studied in the field.
MIGRATION PATTERNS:
Non-migratory. Marked individuals are typically recaptured
within a few meters or at the original point of capture at any given
time of year (34).
COVER/SHELTER REQUIREMENTS:
Shelter is one of the most important aspects of the biology of
X. riversiana as it is for all of the Xantusiidae. The lizards are
intensely secretive and require some form of dense cover. Retreats
for X. riversiana include loose stones on the ground (not firmly
embedded in soil), rock crevices, matlike thickets of vegetation
(especially Lycium, Mesembryanthemum, Atriplex, and clusters of the
cacti Opuntia and Bergerocactus which have accumulations of ground
level stem litter and prostrate living stems), and crevices in the
soil (04,08,34). Wooden boards and other large pieces of debris also
Life History - 1 (DRAFT) - Life History
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
provide good shelter. Clearly a wide variety of retreats are
acceptable to these lizards. Xantusia riversiana can be found in
greatest numbers where the abundance and diversity of shelter is
greatest, and lizards are most likely limited by the numbers of
available retreats. The best habitats are thickets of low-lying
maritime desert scrub vegetation including Lycium, Atriplex,
Bergerocactus, and Opuntia with scattered rock outcrops and loose
boulders on the ground. When living underneath the discrete
dimensions of a stone on the ground, adult X. riversiana typically
select a boulder at least 30 cm in diameter (34).
REPRODUCTIVE SITE REQUIREMENTS:
There are no particular requirements for breeding sites known for
Xantusia riversiana. Because the lizards are sedentary and bear their
young alive it is likely that the requirements for breeding sites are
fulfilled by the general habitat requirements for other aspects of
their biology. In addition to providing cover for thermoregulation
and predator avoidance, the areas under loose stones, vegetation, and
vegetation debris probably are abundant sources of soft-bodied
invertebrates, likely an important food item for new-born night
lizards.
REPRODUCTIVE CHARACTERISTICS:
Studies of the breeding biology of Xantusia riversiana include
12, 13, 05, and 02, the latter being the most comprehensive
investigation. Island night lizards are viviparous and bear from 2-9
young (mean 4.4) in a single annual breeding season during
September-October. Ovulation occurs in May and June and the gestation
period is about 14 weeks. The slow growth rate of X. riversiana makes
it difficult to recognize distinct age classes and accurately
determine age at sexual maturity, but the best estimate of maturation
time is 3-4 years (02). Only about half of the population of female
lizards are gravid in a given year, and the reproductive cycle may be
biennial or irregular (02). The combination of slow growth, late
maturation, and single annual broods by only half the female
population means that this species has an extraordinary low
reproductive potential compared to other lizards of similar size.
PARENTAL CARE:
Parental care is effectively absent. In other species of
Xantusia, females giving birth have been observed to bite and pull at
the amnion sacs, thus assisting the young in freeing themselves of
their embryonic membranes (27,28), but no additional parental
assistance to the young is known.
POPULATION BIOLOGY:
Population density has been very difficult to quantify for
Xantusia riversiana because the lizards are so secretive. Abundance
is controlled to a large extent by the availability of retreats, and
population density is sensitive to fine degrees of local variation in
vegetative cover, rocks, and soil crevices. Population census
techniques applied to this secretive and sedentary species are subject
to biases which make the results uncertain (10,15,29). A sample plot,
Life History - 2 (DRAFT) - Life History
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
200 square m on San Clemente Island which offered the best lizard
habitat with densely scattered rocks permitting nearly exhaustive
sampling, gave lizard density estimates of roughly 1000 per hectare
(29). This figure must be considered as a maximum density because
most of the island's terrain is inferior habitat by comparison.
Reproductive statistics are the best known demographic parameters
for X. riversiana. Sex ratio is 1:1, age at sexual maturity is 3.4
years, brood size averages 4.4, and only about half of adult females
breed in a given year (02,05). Thus an estimate of reproductive rate
is 4.4 x 50% = 2.2 young per adult female per year. By comparison to
other lizards this is a very low figure. Moreover, the 3.4 years
required to reach maturity is an extraordinary delay for a lizard of
this size, and with such a low capacity for reproductive output, X.
riversiana cannot support high rates of predation. The species
represents an extreme pattern of lizard life history characteristics
which normally includie slow growth, low reproductive effort, late
maturation, long lifespan, and low predation (02,30). In this
strategy a relatively low reproductive capacity is usually off-set by
secretive behavior (which reduces predation incidence) and a
relatively long life span. This makes the possibility of exotic
predators overwhelming the reproductive capacity of X. riversiana more
likely.
Predation pressure is not known quantitatively. Kestrels are
probably the most important avian predator because they are abundant
and skilled hunters of small mammals, lizards, and insects. The
island fox feeds primarily on vegetation and arthropods and takes
occasional mice and lizards. Feral cats are probably an important
predator because they frequently take X. riversiana (31), they are
exotic, and thus a relatively new source of predation. It may be
significant that there are no snakes on the islands inhabited by the
island night lizard (32). Many species of snakes feed on lizards.
Since X. riversiana lives at ground level among foliage and under
loose rocks it is vulnerable to snake predators which, unlike
carnivorous mammals and birds, could easily penetrate deep recesses
sheltering the lizards.
Xantusia riversiana does not appear to be limited by any special
food requirements; the species is a generalist omnivore. The lizards
have no significant competitors. It is the only lizard species on San
Nicholas and Santa Barbara Islands, and it shares San Clemente Island
only with the side blotched lizard, Uta stansburiana, which is much
smaller and insectivorous.
SPECIES INTERRELATIONSHIPS:
A variety of mammals and birds actually or potentially prey on
X. riversiana. Native predators include ravens (Corvus corax),
kestrels (Falco sparverius), burrowing owls (Speotyto cuniculavia),
shrikes (Lanius ludovicianus), the Channel Islands fox (Urocyon
littoralis), and perhaps other raptorial birds (31,33). Exotic
predators are feral cats and possibly rats.
OTHER LIFE HISTORY DESCRIPTORS:
The Channel Islands provide a special set of ecological
circumstances for Xantusia riversiana. Natural predators and
Life History - 3 (DRAFT) - Life History
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
competitors are few, and the maritime climatic conditions are
relatively stable. These factors have all been emphasized as
contributing to the survival of X. riversiana on the Channel Islands
and to the extinction of mainland forms from which it was derived (05,
07,08,32). Under these circumstances, X. riversiana persists with a
life history strategy emphasizing low reproductive potential and long
lifespan. This demographic pattern is sensitive to disturbance by
habitat destruction and introduction of exotic species, and these are
the two greatest threats to X. riversiana.
Life History - 4 (DRAFT) - Management Practices
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Suppressing wildfire
Beneficial Prescribed/controlled burning of habitat
Beneficial Restricting/regulating human disturbance of populations
Beneficial Restricting/regulating human use of habitats
Beneficial Land Acquisition
Beneficial Reforestation
Beneficial Controlling/Removing Nonnative Vegetation
Beneficial Controlling/Removing Exotic Vertebrates
Beneficial Controlling/Removing Feral Animals
Adverse Inherent Reproductive Characteristics
Existing Inherent Reproductive Characteristics
Adverse Predation
Existing Predation
Adverse Soil compaction by heavy equipment in mine areas
Existing Soil compaction by heavy equipment in mine areas
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Erosion
Existing Erosion
Adverse Grazing
Existing Grazing
Adverse Vegetation Composition Changes
Existing Vegetation Composition Changes
COMMENTS ON MANAGEMENT PRACTICES -
Xantusia riversiana is regarded as a threatened species because
it has an extremely restricted distribution comprising only 3 of the
California Channel Islands and because the lizard's unique biological
characteristics make it potentially vulnerable to habitat destruction
or to the introduction of exotic predator or competitor species. The
island night lizard, like all xantusiids, is intensely secretive and
confines its activities to dense shelter such as thick, low-lying, and
matted vegetation, loose boulders, crevices in rocks and soil, and
refuse. These characteristics have not made it possible to accurately
assess population status on the islands. Based on the ease of
locating individuals and on habitat appearance, San Clemente Islands
supports the most robust populations followed by San Nicholas and
Santa Barbara Islands (09,10,15,34).
Xantusia riversiana is regarded as a "sensitive" species because
of its unusual life history. For a lizard of its body size, it
represents an extreme because of a slow growth rate, late maturation,
low reproductive potential, long lifespan, and low predation rates
(02,05,12,13).
Any activity which degrades the dense sheltering habitat the
lizards require potentially threatens their populations. Such
possible threats include destruction of the vegetation by feral
herbivorous mammals and grading operations by humans. San Nicholas
Island is extensively eroded and the native vegetation has been
Management Practices - 1 (DRAFT) - Management Practices
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
severely disturbed by earlier sheep and goat ranching. Feral goats,
pigs, and deer are present on San Clemente Island. Feral cats on San
Clemente and San Nicholas Islands currently prey on these lizards.
Santa Barbara Island is managed by the National Park Service, and
conservation practices have been implemented. The successful removal
of feral rabbits and cats from the island in 1981 should contribute to
the stability of X. riversiana populations on Santa Barbara Island.
The impact of military activities on San Clemente and San Nicholas
Islands is generally minor considering the relatively extensive
habitat available; however, large scale activities involving extensive
grading or destruction of vegetation in favorable habitats would have
an adverse effect. Management of these islands by the U.S. Navy
includes programs for conservation and removal of feral animals.
There is no information on the magnitude of the effect of exotic
species on X. riversiana. Precipitous declines in lizard populations
have not been observed over a 10 year period, however, feral goats
have been the source of slow degredation of the island's flora, and
long-term trends are not readily observable in X. riversiana
populations (34).
Additional introductions of exotic animals could affect X.
riversiana. Snakes are not found on any of the islands inhabited by
these lizards (11) and X. riversiana may be vulnerable to snake
predators. Introduction of lizard species could pose a competitive
threat as other species of lizards are absent from Santa Barbara and
San Nicholas Islands, and San Clemente Island is shared by only one
other lizard, Uta stansburiana (11,05). Any future introductions of
grazing mammals in ranch operations could adversely affect the lizards
through the destructive effects these animals have on the island's
vegetation.
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1984. Recovery Plan for the
Endangered and Threatened Species of the California Channel Islands.
U.S. Fish and Wildlife Service, Portland, OR. 165 pp.
Actions recommended for recovery of the island night lizard
include:
1) Habitat restoration, which consists of revegetation to provide
additional habitat, erosion control (check-dam construction), and
removal of exotic plants (e.g., the ice plant), and may include
both controlled burns in grassland and chaparral communities and
natural fire breaks in maritime desert shrub communities.
2) Remove exotic and/or feral animals from the islands.
3) Implementation of management regimes, including modifying the
management plan for Santa Barbara Island.
4) Habitat protection, consisting of promulgation and enforcement of
Navy regulations pertaining to resource management (e.g., setting
aside "standard operating areas", etc.) on the three islands,
preventing the introduction of exotic organisms, and fencing off
critical areas. The Navy and National Park Service should
promulgate and implement regulations to limit habitat
Management Practices - 2 (DRAFT) - Management Practices
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
disturbance, alteration or loss. Restriction of recreational use
of Santa Barbara Island to established trails should be continued
to minimize human disturbance. Ecological Reserves should be
established on San Nicholas and San Clemente Islands.
5) Determining species requirements for essential habitat, habitat
preference, population size and distribution, and effects of
exotic plants.
Cooperative agreements are being developed between the Navy and
Fish and Wildlife Service for resource management; and research and
surveys are being conducted.
Management Practices - 3 (DRAFT) - References
Species LIZARD, NIGHT, ISLAND
Species Id ESIS151002
Date 14 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Cope, E.D. 1883. Notes on the geographical distribution of
Batrachia and Reptilia in western North America. Proc. Acad. Nat.
Sci. Philadelphia. 1883:10-35.
02 Goldberg, S.R. and R.L. Bezy. 1974. Reproduction in the island
night lizard, Xantusia riversiana. Herpetologica 30:350-360.
03 Savage, J.M. 1957. Studies on the lizard family Xantusiidae. III.
A new genus for Xantusia riversiana Cope, 1883. Zoologica
42:83-86.
04 Stebbins, R.C. 1954. Amphibians and Reptiles of western North
America. McGraw-Hill Inc., New York. Pages 267-268.
05 Bezy, R.L., G.C. Gorman, G.A. Adest, and Y.J. Kim. 1980.
Divergence in the island night lizard, Zantusia riversiana (Sauria:
Xantusiidae). Pages 565-583. IN: The California Islands:
Proceedings of a multi-disciplinary symposium. Santa Barbara
Museum of Natural History. D.M. Power (ed.). Santa Barbara, CA.
06 Savage, J.M. 1963. Studies of the lizard family Xantusiidae. IV.
The genera. Los Angeles Co. Mus. Contrib. Sci. 71:1-38.
07 Bezy, R.L. 1972. Karyotypic variation and evolution of the
lizards in the family Xantusiidae. Contrib. Sci. Nat. Hist. Mus.
Los Angeles Co. 227:1-29.
08 Regal, P.J. 1968. An analysis of heat seeking in a lizard. Ph.D.
diss., University of California, Los Angeles.
09 Regal, P.J. 1974. Klauberina riversiana, the island night lizard:
an endangered species. Unpublished report available from: U.S.
Fish and Wildlife Service. 3 pp.
10 Wilson, R.L. 1976. The status of the island night lizard
(Klauberina riversiana). IN: The status of the proposed
endangered species on San Clemente Island. J.K. Larson (ed.).
Unpublished report by U.S. Dept. of the Navy. 10 pp. (Available
from: U.S. Fish and Wildlife Service.)
11 Savage, J.M. 1967. Evolution of the insular herpetofaunas.
Pages 219-227. IN: Proceedings of the symposium on the biology of
the California Islands. R.N. Philbrick (ed.). Santa Barbara
Botanic Garden. Santa Barbara, CA.
12 Amrein, Y.U. and M.B. Amrein. 1951. The number of young found in
the island night lizard. Copeia 1951:180.
13 Brattstrom, B.H. 1951. The number of young in Xantusia.
Herpetologica 7:143-144.
14 Mautz, M.J. 1979. Thermoregulation, metabolism, water loss, and
microhabitat selection in xantusiid lizards. Ph.D. diss., Cornell
University.
15 Wilson, R.L. 1978. A biological assessment of the island night
lizard. Unpublished report available at: California Dept. Fish and
Game. 24 pp and appendices.
16 Schwenkmeyer, R.C. 1949. Food habits of the island night lizard,
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17 Brattstrom, B.H. 1952. The food of the night lizards, genus
Xantusia. Copeia 1952:168-172.
References - 1 (DRAFT) - References
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Species Id ESIS151002
Date 14 MAR 96
18 Knowlton, G.F. 1949. The food of the island night lizard.
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19 Glasier, R. 1958. Increase in locomotor activity following
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20 LaPointe, J.L. 1967. Function of the parietal eye in relation to
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21 Regal, P.J. 1967. Voluntary hypothermia in reptiles. Science
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22 Mautz, W.J. and T.J. Case. 1974. A diurnal activity cycle in the
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23 Lee, J.L. 1974. The diel activity cycle of the lizard, Xantusia
henshawi. Copeia 1974:934-939.
24 Lee, J.L. 1975. The autecology of Xantusia henshawi henshawi
(Sauria:Xantusiidae). Trans. San Diego Soc. Nat. Hist. 17:259-278.
25 Mautz, W.J. 1979. The metabolism of reclusive lizards, the
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26 Slevin, J.R. 1949. Range extension of Xantusia vigilis.
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27 Shaw, C.E. 1949. Notes on broods of two xantusiids.
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28 Cowles, R.B. 1944. Parturition in the yucca night lizard. Copeia
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29 Mautz, W.J. 1982. The status of the island night lizard, Xantusia
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30 Tinkle, D.W. 1969. The concept of reproductive effort and its
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31 U.S. Fish and Wildlife Service. 1981. Recovery Plan for the
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32 Savage, J.M. 1967. Evolution of the insular herpetofaunas. Pages
219-227. IN: Proceedings of the symposium on the biology of the
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33 von Bloeker, K.C. 1967. Land mammals of the southern California
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34 Mauntz, W.J. 1985. Personal communication. Department of
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35 Fellers, G. 1985. Personal communication. Point Reyes National
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36 Bezy, R.L. 1985. Personal communication. Los Angeles County
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37 Mauntz, W.J. 1985. Unpublished data. Department of Community &
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Date 14 MAR 96
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Bezy, R.L. 1972. Karyotypic variation and evolution of the
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