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INVENTORY OF AMPHIBIANS AND REPTILES
OF GEORGE WASHINGTON BIRTHPLACE
NATIONAL MONUMENT
Technical Report NPS/NER/NRTR-2008/110
Joseph C. Mitchell, Ph. D.
Department of Biology
University of Richmond
Richmond, VA 23173
March 2008
U.S. Department of the Interior
National Park Service
Northeast Region
Philadelphia, Pennsylvania
______________________________
Summary
This inventory
was conducted at George Washington Birthplace National Monument (GEWA)
in 2002 and 2003, to 1) document 90% of the amphibians (frogs, salamanders)
and reptiles (turtles, lizards, snakes) of GEWA, 2) describe their associated
habitats, and 3) provide park staff with conservation and management
recommendations. Survey methods included visual encounter surveys, audio
surveys, and road surveys; dipnets, minnow traps, and turtle traps.
Thirteen species of frogs, 11 salamander species, seven turtle species,
six lizard species, and 15 snake species were expected to occur at GEWA
based on known distribution patterns in published literature. The proportion
of species documented during this inventory, based on the expected species
list, was 62% for frogs, 36% for salamanders, 100% for turtles, 50%
for lizards, and 40% for snakes. Total success was 54% of expected species
for amphibians and 57% for reptiles. These success levels are reasonable
based on similar inventories conducted elsewhere in Virginia, and sampling
limitations caused by the drought conditions that prevailed during the
first two years of the study.
Nine habitat types used by amphibians and reptiles at GEWA were described
from the field notes obtained during this inventory, and include beach,
grassland, marsh, mixed hardwoods and pine, mixed hardwoods, mixed pine,
impoundments, swamp, and stream. All habitats surveyed support multiple
species, and most species use both aquatic and terrestrial habitat types.
Habitats that support relatively unique assemblages include hardwood
forests, tidal marshes, and vernal pools. Only one species is habitat-specific,
the Diamond-backed Terrapin (Malaclemys terrapin< terrapin) in
the estuarine marsh. The combination of habitat types used by amphibians
and reptiles at GEWA should be viewed as a matrix of habitats imbedded
within the landscape rather than as separate habitat types, and should
be protected as such.
Although this study documented less than 90% of the expected number
of species for several groups, there are opportunities to register additional
species. This can be accomplished in two ways by park staff: routine
accumulation of digital photographs of road-kills or live amphibians
and reptiles encountered with appropriate documentation appended to
the digital image, and the use of natural history (animal) sighting
cards filled out by knowledgeable visitors. Verification of new species
records should be confirmed by a herpetologist.
Recommendations for GEWA resource management include: (1) Additional
species inventory for salamanders and snakes. Further work to document
snake species at GEWA should include the use of coverboards as part
of its sampling plan. (2) Elucidate park use by Diamond-backed Terrapins
to provide a better understanding of the abundance, distribution, and
habitat use of this rare species. (3) Areas of the park where there
tend to be high concentrations of Box Turtles should be evaluated before
opening them to recreational activities. (4) The public should not be
allowed to release any animals that have been in captivity, and park
management should educate park visitors on this issue. (5) Specific
habitats that should be monitored on a regular basis at GEWA for the
occurrence and persistence of amphibians and reptiles include tidal
marshes, hardwood forests, and vernal pools. (6) Educational materials
should be developed on the ecology, flora and fauna, and their interactions
with human history at GEWA. (7) Park raccoon populations should be monitored,
and population control measures implemented to protect all amphibians
and reptiles, especially turtles and their nests. (8) Develop a comprehensive
natural habitat management plan to conserve amphibians and reptiles
at GEWA. (9) View long-term habitat management at GEWA within the context
of the landscape matrix in and around the park.
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