Amphibians & Reptiles
Inventory
and monitoring of amphibians and reptiles are extremely important in
the South Florida / Caribbean Network. Amphibians are widely recognized
as useful as indicators of ecosystem health. Aspects of their life history
and ecology make them particularly vulnerable to perturbations of natural
systems. Therefore, understanding which species are present now and
monitoring the status of these populations will allow us to monitor
for threats to entire ecosystems, like a canary in a mine shaft.
Several populations
and entire species of amphibians and reptiles have disappeared lately.
Three species of frogs are now believed extinct just from the island
of Puerto Rico. Global climate change, disease, and habitat loss are
believed to be the main causes of herpetofaunal extinctions around the
world. Protecting the species in our National Parks requires more than
just protecting the land. Sensitive natural resources like herpetofaunals
need to be monitored so that threats do not go unnoticed until too late.
Big Cypress National Preserve
Project:
Rice, K.G., Waddle, J.H., Crockett, M.E., Jeffrey, B.M., Rice, A.N.,
and Percival, H.F., 2005, Herpetofaunal Inventories of the National
Parks of South Florida and the Caribbean: Volume III. Big Cypress National
Preserve: U.S. Geological Survey Open-File Report 2005-1300. 
Download final report: (1,831 KB)
Objectives:
The goal of this project was to create a geo-referenced inventory of
amphibian species by using a new analytical technique of estimating
the proportion of sites occupied (PAO) by each species by using visual
encounter surveys and anuran vocalization surveys, and to establish
a protocol that could be used for future monitoring efforts within the
Big Cypress National Preserve. This study represents the first thorough
inventory of amphibian species in Big Cypress National Preserve.
Conducted from 2002 through 2003 this study detected 18 amphibian species and 34 reptilian species and encountered nearly 3,000 amphibian and reptile individuals. Opportunistic collections and limited drift fence data were used to augment the visual encounter methods for highly aquatic or cryptic species. The snout-to-vent length of each amphibian was measured (n = 1,904).
Every amphibian species historically
found in Big Cypress National Preserve was detected during this project,
except for the pinewoods treefrog, Hyla femoralis. Although this study
showed no evidence of amphibian decline, some threats were observed
that could eventually lead to a decline, including; recreational use
of off-road vehicles, introduction of non-native species, and human
interference of the South Florida hydrological cycle. Introduced species
are expanding their range in the park, especially the Cuban treefrog
(Osteopilus septentrionalis)
and the giant toad (Bufo marinus),
and are competing with and eating several native frog species. Future
monitoring is highly recommended.
Date:
Starting 06/01 - Ending 10/01
Cooperator:
Dr. Kenneth G. Rice, U.S. Geological Survey
J. Hardin Waddle, and Marquette E. Crockett, Florida Cooperative Fish
and Wildlife Research Unit
Brain M. Jeffery, University of Florida Department of Wildlife Ecology
and Conservation
H. Franklin Percival, Florida Cooperative Fish and Wildlife Research
Unit
Contact Information:
ken_g_rice@usgs.gov
Biscayne National Park
Project:
Rice, K.G., Waddle, J.H., Crockett, M.E., Bugbee, C.D., Jeffery, B.M.,
and Percival, H.F., 2006, Herpetofaunal Inventories of the National
Parks of South Florida and the Caribbean: Volume IV. Biscayne National
Park: U.S. Geological Survey Open-File Report 2006.
Download final report: (3.1
MB)
Objectives:
The goal of this project was to create a geo-referenced inventory of
amphibian species by using a new analytical technique of estimating
the proportion of sites occupied (PAO) by each species by using visual
encounter surveys and anuran vocalization surveys, and to establish
a protocol that could be used for future monitoring efforts within the
Biscayne National Park.
Two hundred thirty six sampling trips to 37 sites established throughout
the park encountered a total of 9 amphibian species (6 native, 3 non-native)
and 14 reptile species during this survey. PAO estimates were generated
for six of the more common amphibians. The 3 non-native species were
the Cuban treefrog (Osteopilus septentrionalis),
the marine or cane toad (Bufo marinus)
and the greenhouse frog (Eleutherodactylus
planirostris planirostris) were detected three times as often
as the native species.
Date:
Starting 06/01 - Ending 10/01
Cooperator:
Dr. Kenneth G. Rice, U.S. Geological Survey
J. Hardin Waddle, and Marquette E. Crockett, Florida Cooperative Fish
and Wildlife Research Unit
Brain M. Jeffery, University of Florida Department of Wildlife Ecology
and Conservation
H. Franklin Percival, Florida Cooperative Fish and Wildlife Research
Unit
Contact Information:
ken_g_rice@usgs.gov
Buck Island Reef National Monument
Project Title:
Herpetological Inventory of Buck Island Reef National Monument
Download final report: (1,026 kb).
Date:
Starting 06/01 - Ending 10/01
Cooperator:
Dr. Kenneth G. Rice, U.S. Geological Survey
J. Hardin Waddle, and Marquette E. Crockett, Florida Cooperative Fish
and Wildlife Research Unit
Brain M. Jeffery, University of Florida Department of Wildlife Ecology
and Conservation
H. Franklin Percival, Florida Cooperative Fish and Wildlife Research
Unit
Contact Information:
ken_g_rice@usgs.gov
Discussion:
Although the herpetofauna of BUIS is small, it is important.
Two of the three lizards on the island are endemic to St. Croix and
the surrounding cays. All three of the marine turtles are protected
by international treaty, and the island is a significant breeding site
for the Atlantic Hawksbill. The island may have once had a natural population
of the federally endangered St. Croix ameiva. Now that mongoose and
rat eradication has succeeded it may again serve as suitable habitat
for the St. Croix Ameiva if resource managers decide to attempt anther
introduction.
The
only introduced species detected on Buck Island , the tropical house
gecko, is ubiquitous throughout the West Indies (Schwartz and Henderson
1991). It is easily transported on boats and in building materials,
the likely source of introduction onto Buck Island . This species is
primarily edificarian, and has not been shown to interact negatively
with the native herpetofauna elsewhere (Meshaka 1996). The threat from
this species appears negligible.
The eradication of the mongoose and the black rat from Buck Island has probably been advantageous to the herpetofauna. This has eliminated a significant source of nest predation on marine turtles. It has probably reduced predation on the lizard fauna of Buck Island as well. The current resource management strategy of maintaining rodent eradication should allow the native fauna to thrive. Further study comparing the density of populations of Sphaerodactylus beattyi and Anolis acutus on Buck Island with populations on St. Croix where mammalian predators are present might be interesting. A comparison study could show what effect the mammals have had on the herpetofauna on St. Croix .
The herpetofauna
of St. Croix is relatively small and highly endemic compared to similar
islands in that part of the Caribbean (Philibosian and Yntema 1977).
Of the ten non-marine reptile and amphibian species native to St. Croix,
five (50%) are endemic to the island and its surrounding cays. Two species
of the original native herpetofauna are now extinct on St. Croix , the
endemic St. Croix ground snake (Alsophis sancticrucis) and
the slippery-back skink (Mabuya mabouia). Buck Island appears
to be too dry to support amphibians, but it does protect two of the
three extant endemic reptiles. If Ameiva polops is reintroduced
to the island it will protect all three of the reptiles endemic to St.
Croix .
Everglades National Park
Project Title:
Rice,
K.G., Waddle, J. H., Crockett, M.E., Jeffery, B.M., and Percival, H.F.,
2004, Herpetofaunal Inventories of the National Parks of South Florida
and the Caribbean:Volume I. Everglades National Park: U.S. Geological
Survey Open-File Report 2004-1065.
Download final report: (3,000KB)
Objectives:
The goal of this project was to create a geo-referenced inventory of
amphibian species by using a new analytical technique of estimating
the proportion of sites occupied (PAO) by each species by using visual
encounter surveys and anuran vocalization surveys, and to establish
a protocol that could be used for future monitoring efforts within the
Everglades National Park.
Four hundred thirteen reptiles
and 1,788 amphibians were encountered during visual encounter surveys
and anuran vocalization surveys; an additional 177 amphibians and 142
reptiles were captured in drift fences, funnel traps, and by opportunistic
encounter during the study (2000-2003). Fifteen of the 16 known amphibian
species to live in Everglades National Park were detected during the
study. The Everglades dwarf siren (Pseudobranchus
axanthus belli) was the only amphibian species not found, but
there is no evidence to conclude that it does not still inhabit Everglades
National Park. One amphibian species that was not previously listed
was found: the giant toad (Bufo marinus).
This study found no evidence of amphibian decline within Everglades
National Park. This study did not target reptiles, but the authors still
encountered 37 of the 57 reptiles known to inhabit Everglades National
Park.
Date:
Starting 06/01 - Ending 10/01
Cooperator:
Dr. Kenneth G. Rice, U.S. Geological Survey
J. Hardin Waddle, and Marquette E. Crockett, Florida Cooperative Fish
and Wildlife Research Unit
Brain M. Jeffery, University of Florida Department of Wildlife Ecology
and Conservation
H. Franklin Percival, Florida Cooperative Fish and Wildlife Research
Unit
Contact Information:
ken_g_rice@usgs.gov
Virgin Islands National Park
Project:
Rice, K.G., Waddle J.H., Crockett M.E., Carthy R.R., Percival H.F.,
2005, Herpetofaunal Inventories of the National of South Florida and
the Caribbean: Volume II. Virgin Islands National Park: U.S. Geological
Survey Open-File Report 2005-1301.
Download final report: (3,000KB)
Objectives:
The
goal of this project was to create a geo-referenced inventory of amphibian
species by using a new analytical technique of estimating the proportion
of sites occupied (PAO) by each species by using visual encounter surveys
and anuran vocalization surveys, and to establish a protocol that could
be used for future monitoring efforts within the Virgin Islands National
Park (VIIS).
This study was conducted from 2000 to 2003 at 21 transects which utilized
the existing park trail network. Overall, 216 individual amphibians
and 38 individual reptiles were encountered; an additional 58 amphibians
and 10 reptiles were found in opportunistic encounters. Six of the 8
known amphibian species were found, and an additional species, the Cuban
treefrog (Osteopilus septentrionalis)
was detected. Nine reptile species were documented.
A number of the potential threats to the amphibians were noted. The
Cuban treefrog (Osteopilus septentrionalis)
an invasive species might decrease populations of native amphibian species.
Introduced mammalian predators are a potential threat to both the reptiles
and amphibians, while mammalian grazers might have indirect effects
on both through habitat modification. Loss of habitat to development
outside the park boundary could also harm populations of amphibians
and reptiles within VIIS.
Date:
Starting 06/01 - Ending 10/01
Cooperator:
Dr. Kenneth G. Rice, U.S. Geological Survey
J. Hardin Waddle, and Marquette E. Crockett, Florida Cooperative Fish
and Wildlife Research Unit
Brain M. Jeffery, University of Florida Department of Wildlife Ecology
and Conservation
H. Franklin Percival, Florida Cooperative Fish and Wildlife Research
Unit
Contact Information:
ken_g_rice@usgs.gov