Content uploaded by Jesus Rivas
Author content
All content in this area was uploaded by Jesus Rivas on Jun 29, 2016
Content may be subject to copyright.
consumption as this might be an important way for hatchling C.
acutus
to behaviorally osmoregulate in saline environments
(Thorbjarnarson 1989.
In P. M. Hall [ed.], Crocodiles: Their
Ecology, Management, and Conservation, pp. 228-258. IUCN,
Gland, Switzerland).
Fischer et al. (1991. J. Herpetol. 25:253-256) contend that
hatchling
Alligator mississippiensis
cannot effectively capture
small prey owing to a long snout in relation to body size (Mean
HL/SVL ratio = 0.31; S.E. = ± 0.001; N = 288), and instead rely
on metabolizing residual yolk as an energy source. However, no
significant difference exists between the HL/SVL ratio of C.
acutus
and A.
mississippiensis
hatchlings (ANOVA;
F1
,
312 =
0.002;
P >
0.05), and the prevalence of prey remains among stomach contents
indicates C.
acutus
neonates are adept predators, which begin
feeding within 7 days of hatching. Therefore, failure of
A.
mississippiensis
hatchlings to capture small prey might not be
because of morphological constraints.
Submitted by
STEVEN G. PLATT,
Wildlife Conservation
Society, 2300 Southern Boulevard, Bronx, New York 10460-1099,
USA (e-mail• splatt225@aol.com
),
THOMAS R. RAINWATER,
The Institute of Environmental and Human Health, Department
of Environmental Toxicology, Texas Tech University Box 41163,
Lubbock, Texas 79409-1163, USA (e-mail:
thomas.rainwater@tiehh.ttu.edu
), and
JOHN B.
THORBJARNARSON, Wildlife Conservation Society, 2300
Southern Boulevard, Bronx, New York 10460-1099, USA
(Jthorbjarnarson@wcs.org
).
CROCODYLUS INTERMEDIUS
(Orinoco Crocodile).
AGE AT
FIRST REPRODUCTION.
Hunting pressure has extirpated or
nearly extirpated many crocodilian populations. As a consequence,
conservation efforts in many countries have focused on both
protecting land and head-starting wild-caught or farmed neonates
which are then reintroduced to protected areas. Orinoco crocodiles,
Crocodylus intermedius,
were nearly extirpated in the Venezuelan
llanos prior to a ban on their commercial harvest during the 1970s
(Munoz and Thorbjarnarson 2000. J. Herpetol. 34:397-403;
Thorbjarnarson 1992. Crocodiles: An Action Plan for their
Conservation, IUCN/SSC. 136 pp.). Since 1990, conservation
efforts have resulted in the release of > 1300 juveniles in protected
private and public lands (C. Chavez, pers. comm.). To date, only
modest efforts have been devoted to assessing success of
reintroduced individuals. Available data show that animals survive
and remain in protected areas (Munoz and Thorbjarnarson,
op.
cit.),
but whether re-introduced individuals were reproducing was
uncertain. Here, we document the successful nesting of
reintroduced crocodiles in two large cattle ranches located in
Distrito Munoz, State of Apure, Venezuela (7°30'N, 69°18W).
Both ranches, Hatos El Frio (80,000 ha) and El Cedral (54,000
ha), are located in the flooded savannas of the Venezuelan Ilanos
that previously harbored
C. intermedius,
where hunting pressure
had locally extirpated the species (Arteaga and Hernandez 1996.
Proceedings of the 13th Working Meeting of the Crocodile
Specialist Group, pp. 207-222, IUCN). In 1990, an initial group
of 31 juveniles 1-4 years of age was released in Hato el Frio. In
1994, five juveniles were released in Hato El Cedral; four of these
were born in 1993 (sizes ranging roughly from 60 to 80 cm in
total length) and the remaining juvenile was between 3 and 5 years
old. These reintroduced juveniles were regularly observed, but lack
of appropriate nesting habitat in the near vicinity limited
opportunities for reproduction. As a result, from 1996 to 2001
management built artificial nesting sites. These artificial sites
consisted of —1 m
3
holes excavated in the edges of the water bodies
that were filled with river sand from beaches where C.
intermedius
had nested historically.
In March 1998, we found the first two nests (52 and 56 eggs)
with fertile eggs. The females that laid these clutches were not
captured, so their age is uncertain; however, this site had animals
up to 12 years old. In March 2001, at least two of the females
released in El Cedral laid eggs. Clutch fertility (30+ eggs in one
case; predators destroyed the other nest) could not be assessed
because ranch workers mistakenly removed the eggs and they were
not incubated for any length of time.
Females that laid the eggs at El Cedral were not caught, but the
only
C. intermedius
present were from the 1994 release. Thus,
minimum reproductive age for females is no greater than 8 years
because only one older
C. intermedius
was known to be present
and two clutches were laid. Two of the released females caught in
January 2001 were 322 and 342 cm total length, and weighed 145
and 175+ kg, respectively.
Some release sites selected for
C. intermedius
have been on
public lands protected only on paper (Arteaga and Hernandez,
op.
cit.;
Munoz and Thorbjamarson,
op. cit.).
Fishing and poaching
have resulted, at best, in limited success for such public land re-
introductions. Our data show that re-introductions on private lands
where systematic protection is enforced can be successful, at least
over a few years. Continued investigation of this promising pattern
is needed to determine whether it will continue.
Estacion Cientifica Amigos de Doiiana, Available Light, The
National Geographic Society, and Association for Conservation
Research and Education provided funding and logistic support;
COVEGAN allowed us to work on their ranch; and Mauricio
Urcera, Jose Ayarzaguena, Tulio Aguilera, Carlos Chavez, Pedro
Azuaje, and John Thorbjarnarson helped in data collection .
Submitted by
JESUS A. RIVAS,
National Geographic
Television, 1145 17th Street NW, Washington, D.C. 20036, USA
(e-mail: anaconda@prodigy.net),
and
RENEE Y. OWENS,
1152
Sloan Canyon Road, Jamul, California 91935, USA.
LACERTILIA
ANOLIS QUERCORUM
(Gray Mole).
GENERAL ECOLOGY.
An unfortunate consequence of the huge diversity in the genus
Anolis (>
300 spp.; Guyer and Savage 1986. Syst. Zool. 35:509-
631) is that ecology of many species is unknown. Sparse knowledge
for anoles is marked in Mexico, where few taxa have been studied
(e.g., Ramirez-Bautista and Vitt 1997. Herpetologica 53:423-431).
Here, we address this gap through provision of a few data on the
infrequently observed anole
Anolis quercorum,
a species for which
no data have become available since its description from
Nochixtlan, Oaxaca, Mexico (Fitch 1978. Contrib. Biol. Geol.,
Milwaukee Pub. Mus. 20:1-15).
Over 4 days (14 May, 12 July, and 2 and 22 September 1998),
we collected six A.
quercorum
(four females [field numbers: JLE
3004-5, 3024; and LOL 014] and two males [JLE 2551 and LOL
Herpetological Review 33(3), 2002
203
