Monitoring Amphibian and Reptile Populations on the INL:
Indicators of Environmental Health and Change
Many amphibian and reptile species have characteristics that
make them sensitive environmental indicators. The main research
goal of this project is to provide indicators of environmental
health and change by monitoring the distribution and population
trends of amphibians and reptiles on the INL Site. This
information is important to the DOE for several reasons:
as an indicator of environmental health and change;
for management of speciﬁc populations of sensitive
meeting NEPA requirements regarding the siting of future
avoiding potentially dangerous snake-human interactions;
providing a foundation for future research into the
ecological importance of these species.
The main objective of this project is to monitor amphibian and
reptile distribution on the INL Site. Speciﬁc objectives for
2007 included the following:
Continue monitoring snake
and lizard populations at the three main den complexes
program to include a 170 km driving loop to complement the
den data (Figure 9-1). This has been added because Denim
Jochimsen’s data showed that the proportion of gopher snakes
on the roads is higher than at the main den sites;
Continue to monitor breeding sites
for Great Basin Spadefoot “toads” (Spea intermontana)
Continue entering current
herpetological information into a geographic information
system (GIS) tool database;
Provide herpetological expertise, as
Provide snake safety workshops; and
Provide educational opportunities for
undergraduate and graduate students.
Speciﬁc accomplishments for
2007 include the following:
We continued monitoring
of snake populations at three den complexes (Cinder
Butte, Crater Butte, and Rattlesnake Cave) allowed us to
increase the total number of snakes captured by 481
snakes (Figure 9-2), 332 of which were new marks.
We found 51 snakes during
eight road cruising trips.
We did not conﬁrm
spadefoot toad breeding activity at the Big Lost River
sinks in 2007.
In two man hours of
searching we were not able to conﬁrm the presence of
Long-nosed Leopard Lizards (Gambelia wislizenii)
on the INL Site in 2007.
We conducted three snake
safety talks in May of 2007 at the INL Site.
The number of marked snakes
on the INL Site was increased to 4,400 in 2007, which
includes all snakes PIT-tagged since 1994 and marking data
collected at Cinder Butte from 1989 to 1994.
We found that in 2007, 10
percent of females were gravid at Cinder Butte, 30
percent were gravid at Crater Butte, and 10 percent were
gravid at Rattlesnake Cave.
No observations of a
leopard lizard (Gambelia wislizenii) were made at
Circular Butte in 2007. Western skinks (Eumeces
skiltonianus) were found in funnel traps at
Rattlesnake Cave. Sagebrush lizards (Sceloporus
graciosus) were found across the entire INL Site.
We found 34 gopher
snakes, 16 rattlesnakes, and one unidentiﬁable snake
during our road cruising surveys (Figure 9-3).
Spadefoot toad (Spea
intermontana) breeding was not observed in the Big
Lost River Sinks.
herpetological expertise in the form of snake safety
talks for the INL Site, as well as, at the Idaho Falls
Earth Day celebration and to elementary school children
at different schools and libraries.
Through the continuation
of Scott Cambrin’s masters research he has also started
to look at some of the factors affecting body condition
and pregnancy rates. Using the results from a laboratory
study he has modeled neonate overwinter survival for the
three main den sites (Figure 9-4).
Plans for Continuation
Scott Cambrin will complete a thesis and approximately two
manuscripts will be submitted to peer reviewed scientiﬁc
Investigators and Affiliations
Scott Cambrin, Graduate
Student, Herpetology Laboratory, Department of Biological
Sciences, Idaho State University (ISU), Pocatello, Idaho
Charles R. Peterson,
Professor, Herpetology Laboratory, Department of Biological
Sciences, ISU, Pocatello, Idaho
Idaho State University Graduate Student Research and Scholarship
U.S. Department of Energy Idaho Operations Ofﬁce