Tropidurus hispidus (NCN). Frog predation

Full text

Herpetological Review 40(2), 2009228
TROPIDURUS HISPIDUS (NCN). FROG PREDATION. As
with most Tropidurus, the diet of T. hispidus is mainly arthropods
(e.g., T. oreadicus and T. spinulosus, Colli et al. 1992. J. Herpetol.
26:66–69; T. torquatus, Fialho et al. 2000. J. Herpetol. 34:325–330;
T. montanus, Van Sluys et al. 2004. J. Herpetol. 38:606–611). Ants,
beetles, insect larvae and termites comprise the numerical majority
of T. hispidus diet in rock outcrops in Brazilian Amazonia (Vitt et
al. 1996. J. Trop. Ecol. 12:81–101). Plant material (e.g., leaves,
fl owers and fruits) is also an important portion of the total volume
ingested in different T. hispidus populations: one from a caatinga
biome (Vitt 1995. Occ. Pap. Oklahoma Mus. Nat. Hist. 1:1–29) and
one from “campos rupestres” (rocky meadow) habitats (Van Sluys
et al., op. cit.). Besides invertebrates and plant material, T. hispidus
occasionally eat small vertebrates, such as frogs (Vitt et al. 1996,
op. cit.) and other lizards (Vitt 1995, op. cit.). Here, we report a frog
previously unreported as prey for T. hispidus in a caatinga biome
at the Estação Ecológica do Seridó (ESEC Seridó), Serra Negra do
Norte municipality, Estado do Rio Grande do Norte, Brazil.
During an ecological study of Tropidurus in rocky habitats at
ESEC Seridó (06.5767°S, 37.2558°W, datum: WGS84; elev. 192
m) a total of 84 stomachs of T. hispidus were analyzed. The stom-
ach contents of an adult female (99 mm SVL) captured on a rock
surface on 14 February 2008, included an adult hylid frog Scinax
x-signatus (30.0 mm in length [SVL], 20.0 mm in width and 6,280
mm3 in volume).
Based on stomach analysis of 74 T. hispidus by Vitt et al. 1996
(op. cit.), 11 frogs were found as prey in 6 lizards. The microhylid
Elachistocleis ovalis was the only anuran identifi ed to species
among these frogs. However, in contrast to our observation, all
the frogs recorded by Vitt et al. 1996 (op. cit.) were juveniles and
comprised a relatively small total volume (1,473 mm3).
The T. hispidus (CHBEZ 1994) was deposited in the herpetologi-
cal collection of Universidade Federal do Rio Grande do Norte,
Natal City. We thank the Programa PELD/CNPq - Caatinga:
Estrutura e Funcionamento for logistic support, U. Caramaschi
for identifi cation of the frog, and M. Hayes for helpful comments
on this note. A grant from the Conselho Nacional de Desenvolvi-
mento Científi co e Tecnológico (CNPq) to L.B. Ribeiro (process
141993/2006-5) supported this study, and IBAMA provided a
permit (Permit 206/2006 and Process 02001.004294/03-15).
Submitted by LEONARDO B. RIBEIRO (e-mail: ri-
beiro.lb@gmail.com) and ELIZA M. X. FREIRE (e-mail:
elizajuju@ufrnet.br), Programa de Pós-Graduação em Psico-
biologia, Universidade Federal do Rio Grande do Norte, Centro
de Biociências, Departamento de Fisiologia, Caixa Postal 1511;
Campus Universitário Lagoa Nova, CEP 59078-970, Natal, Rio
Grande do Norte, Brazil.
TROPIDURUS SEMITAENIATUS (NCN). DRINKING
BEHAVIOR. Many reptiles drink water (Minnich 1982. In
Biology of the Reptilia, pp. 325–395. Academic Press, New York,
New York), and many use behavioral strategies and adaptations
in morphology and physiology associated with living in habitats
with little water (Minnich 1979. In Comparative Physiology
of Osmoregulation in Animals, pp. 391–641. Academic Press,
London, UK). One such behavior, drinking water, has been
recorded relatively infrequently among lizards dwelling in arid
habitats (e.g., Meyer 1966. Copeia 1966:126–128; Fusari 1985.
Copeia 1985:981–986; Sherbrooke 1993. J. Herpetol. 27:270–
275; Sherbrooke 2004. Amphibia-Reptilia 25:29–39). Hence, we
describe drinking behavior in the tropidurid lizard Tropidurus
semitaeniatus for the fi rst time.
Tropidurus semitaeniatus is broadly distributed in the rocky
habitats of the semi-arid caatingas of northeastern Brazil
(Vanzolini et al. 1980. Répteis das Caatingas. Acad. Bras. de
Ciênc., Rio de Janeiro, Brazil. 161 pp.). High temperatures, low
humidities, and low, often-irregular precipitation concentrated
in 2–3 months of each year characterize these caatingas (Nimer
1972. Rev. Bras. Geog. 34:3–51; Reis 1976. Ann. Acad. Bras. de
Ciênc. 48:325–335; Andrade-Lima 1981. Rev. Bras. Bot. 4:149–
153).
Our observations were made at a caatinga at the Estação
Ecológica do Seridó (Ecological Station of the Seridó [ESEC
Seridó]; 6.5767°S, 37.2558°W, datum: WGS84; elev. 192 m),
Serra Negra do Norte municipality, Estado do Rio Grande do
Norte, Brazil.
At 0810 h and 0930 h, respectively, on 7 and 8 October 2007,
LBR observed the drinking behavior in 8 T. semitaeniatus to
which he experimentally offered water in the course of making
focal animal observations of foraging behavior. Water was
offered to lizards by dripping it directly on a rock surface (~1
m2) and on dry leaves at a distance ~1 m from the animals using
a 20-ml syringe. Lizards rapidly demonstrated interest in water
offered as soon as they located it visually or heard the sound of
the drops on dry leaves. During this month of heavy drought, air
temperature and humidity at the time of observations on the fi rst
day was 33.2ºC and 38.6%, whereas at the time of observations
on the second day, air temperature was 32.3ºC and humidity was
36.1%.
To drink the water from warm rock surfaces, each T.
semitaeniatus kept its forelegs fl exed such that its belly did not
contact the substrate. With the head oriented down, their snout
touched the accumulated water in the rock fi ssures of the rock
(Fig. 1) and based on contractions of the throat, they seemed
FIG. 1. Tropidurus semitaeniatus drinking water in the rock fi ssure of
the rock at the Estação Ecológica do Seridó, Brazil.

Herpetological Review 40(2), 2009 229
to swallow it. Where water was in a thin laminar layer on rock
surfaces, the lizards tongue-fl icked rapidly in an apparent attempt
to maximize their intake before the water evaporated from warm
surfaces (> 40°C). Lizards also alternating quickly among fi ssures
holding water also seemed to be an attempt to maximize intake.
Water offered in dry leaves appeared to allow more time to access
than that offered on warm rocks, and water on dry leaves also
seemed to be more easily consumed.
Given the scarce precipitation on caatingas, T. semitaeniatus are
thought to acquire most of their water from animal prey, mainly
termites (Vitt 1995. Occ. Pap. Oklahoma Mus. Nat. Hist. 1:1–29),
because vegetation becomes completely dry during drought. The
drinking behavior we described may be used opportunistically by
T. semitaeniatus as soon as the annual rains appear in northeastern
Brazil.
We thank the Programa PELD/CNPq – Caatinga: Estrutura e
Funcionamento for logistic support, and M. Hayes for suggestions
on the manuscript. This study was supported by a research grant
from the Conselho Nacional de Desenvolvimento Científi co e
Tecnológico (CNPq) to L.B. Ribeiro (process 141993/2006-5), and
the permit for the work was given by IBAMA (Permit 206/2006
and Process 02001.004294/03-15).
Submitted by LEONARDO B. RIBEIRO (e-mail: ri-
beiro.lb@gmail.com); and ELIZA M. X. FREIRE (e-mail:
elizajuju@ufrnet.br), Programa de Pós-Graduação em Psico-
biologia, Universidade Federal do Rio Grande do Norte, Centro
de Biociências, Departamento de Fisiologia, Caixa Postal 1511;
Campus Universitário Lagoa Nova, CEP 59078-970, Natal, Rio
Grande do Norte, Brazil.
UTA STANSBURIANA (Side-Blotched Lizard). NOCTURNAL
ACTIVITY; FORAGING BEHAVIOR. Uta stansburiana is a
small (up to 6.3 cm SVL) sceloporine lizard common throughout
much of the arid western United States (Stebbins 2003. A Field
Guide to Western Reptiles and Amphibians. Houghton Miffl in,
New York, New York. 533 pp.) that is typically associated with
mixed fi ne substrate and rock habitats below elevations of ca.
1,850 m (St. John 2002. Reptiles of the Northwest. Lone Pine,
Auburn, Washington, USA. 256 pp.). Its diel activity pattern is
typically bi-modal, occurring during the morning (beginning at
0900 h) or early evening (1730–1830 h), and centered around
foraging or mate searching behavior (Parker and Pianka 1975.
Copeia 1975:615–632). Reports of crepuscular activity exist for
Sceloporus jarrovi and S. virgatus in southeast Arizona (Duncan
et al. 2003. Southwest. Nat. 48:218–222), but reports of nocturnal
activity among sceloporine lizards are rare. Hence, here I report an
observation of nocturnal behavior in U. stansburiana.
At 0115 h on 18 May 2008, I observed 3 adult U. stansburi-
ana on Huntzinger Road in eastern Kittitas County, Washington
(46.86305°N, 119.97155°W, datum: WGS84; elev. ca. 185 m).
Two individuals appeared to be basking (via thigmothermy) on the
road. Their limbs were splayed out and each had a fl attened appear-
ance. A third animal was observed actively pursuing insects on the
road ca. 3 m away (the road was illuminated via a full moon). Air
temperature at the time of observation was 28°C, and the daytime
high in the area, recorded at 1530 h 1.0 m above the surface in the
shade, approached 43.5°C. Surrounding habitat was shrub-steppe
characteristic of much of central Washington (Daubenmire 1970.
Steppe Vegetation of Washington. Washington Agric. Exp. Station
Tech. Bull. 62, Pullman, Washington. 131 pp.), dominated by big
sagebrush (Artemesia tridentata), rabbitbrush (Chrysothamnus
spp.), various annuals, and in some areas, a few invasive exotics
(Bromus sp. and Centaurea sp.).
I thank M. Hayes for editoral suggestions.
Submitted by ROBERT E. WEAVER, School of Biological
Sciences, Washington State University, Pullman, Washington,
USA; e-mail: weaverr@wsu.edu.
SERPENTES — SNAKES
BOA CONSTRICTOR (Boa Constrictor). DIET. Boa constrictor
is a widely distributed, large-bodied dietary generalist that con-
sumes a wide taxonomic diversity of prey including invertebrates,
fi sh, lizards, birds, and mammals (Quick et al. 2005. J. Herpetol.
39:304–307). Though dietary habits of continental B. constric-
tor are well-documented, less data exist concerning the diet of
populations inhabiting neotropical islands. Iguanas of the genus
Ctenosaura have been documented in the diet of B. constrictor
inhabiting the Bay Islands of Honduras (Gutsche 2005. Herpetol.
Rev. 36:317; Reed et al. 2006. Herpetol. Rev. 37:84) and Green
Iguanas (Iguana iguana) have been reported in the diets of indi-
viduals inhabiting Aruba (Quick et al., op cit.). Here we report an
additional iguana prey item for B. constrictor from the island of
Dominica in the Lesser Antilles, West Indies.
On 13 July 2004, MG observed a dead B. constrictor (ca. 2 m to-
tal length) on the main road passing through Desirade (15.58333°N,
61.31667W°) in Woodford Hill on the northeastern coast of
Dominica. An adult female Iguana delicatissima (Lesser Antil-
lean Iguana; ca. 27 cm SVL) was protruding through a laceration
in the snake’s body. Eggs from the iguana were strewn along the
road and a broken and a rotten branch of a White Cedar (Tabebuia
pallida) was discovered next to the specimen. It is assumed that
the snake captured and ingested the iguana in the White Cedar and
its excessive mass caused the rotten tree limb to break. Another
B. constrictor (ca. 2 m TL) was discovered by CRK and LP on 24
August 2007 in the Batalie Beach area (15.45027°N, 61.44694°W)
located on the west coast of Dominica. The snake was resting on the
ground in a shallow cave along a rock wall 12 m from the ocean.
A single scat (16 × 3 cm) was discovered 1 m from the snake. The
scat contained skeletal elements, crest scales, and six eggs of I.
delicatissima. These observations augment the list of prey items
for B. constrictor and suggest that large-bodied iguanas may be
more common prey than previously documented.
We thank the Center for Conservation and Research for Endan-
gered Species (CRES) of the Zoological Society of San Diego for
support.
Submitted by CHARLES R. KNAPP, Conservation and Re-
search of Endangered Species, Zoological Society of San Diego,
15600 San Pasqual Valley Road, Escondido, California 92027,
USA (e-mail: cknapp@ufl .edu); MCDONALD GREENAWAY
(e-mail: forestry@cwdom.dm), ARLINGTON JAMES (e-mail:
arljames@cwdom.dm), Forestry, Wildlife and Parks Division, Bo-
tanic Gardens, Roseau, Commonwealth of Dominica, West Indies;
and LYNDON PRINCE, Salisbury Village, Commonwealth of
Dominica, West Indies.