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Introduction
Approximately 460 species of amphibians and reptiles
are known to occur in the continental United States.
Amphibians and reptiles are vertebrates, along with
fish, birds, and mammals. Worldwide, there are approximately
4,600 known amphibian species, similar
to the number of known mammal species (approximately
4,000). There are about 6,000 known reptile
species worldwide. The term herps refers to amphibians
and reptiles as a group. Most herps lay eggs; although,
some give birth to live young. The body temperatures
of nearly all amphibians and reptiles are
primarily determined by external sources of heat such
as the sun, water, or ground. This limits their distribution
and activity time, but allows them to live on
about one-tenth of the energy that similar-sized mammals
and birds require. Herps control their body temperatures
by moving to cooler or warmer areas as
necessary.
Reptiles have dry skin and scales, shields, or plates to
help keep their skin from losing moisture. Most reptiles
with feet have claws on their toes. Reptiles lay
shelled eggs or bear live young. Young reptiles have
the same body forms as their parents, though they
may differ in color or pattern. Reptiles living in North
America include turtles and tortoises, crocodiles and
alligators, lizards, and snakes.
Many amphibians have moist skin that lacks scales,
feathers, or hair. Most adult amphibians have lungs,
but respiration also occurs through the skin—a process
that can only occur if the skin is moist. Unlike
reptiles, amphibians’ toes are usually clawless, and
their eggs lack shells and are laid in water or a moist
environment to protect them from drying out. In general,
amphibian eggs hatch into aquatic larvae (or tadpoles)
that eventually metamorphose into the adult
form that is more terrestrial. Common amphibians of
North America include salamanders, frogs, and toads.
This leaflet was created to provide landowners with
information about amphibians and reptiles. By reading
this leaflet, landowners will recognize the ecological
value of herps, learn about threats to these animals,
and gain insight on what they can do to help.
The leaflet presents the habitat requirements of amphibians
and reptiles and offers suggestions for increasing
habitat quality and availability.
Ecological significance
Amphibians and reptiles play a major role in ecological
food webs, as both predators and prey. As consumers
of insects, rodents, and other pest species,
herps also provide a significant benefit to agriculture
and recreational activities. When abundant, amphibians
can consume substantial quantities of favored
prey organisms, perhaps serving to limit prey populations.
For example, salamanders appear to play important
roles in organizing many terrestrial and aquatic
communities. The larvae of mole salamanders are
top predators in vernal pond communities and influence
the abundance and diversity of aquatic invertebrates
and other amphibians therein. By serving as
prey, herps provide food for small mammals, birds,
and other herps.
Amphibians and reptiles are particularly sensitive
to habitat disturbance. Because of their close contact
with air, water, and soil, amphibians are considered
to be good indicators of environmental health.
Amphibians have highly permeable skin that rapidU.S.
Fish and Wildlife Service
Tiger salamander (Ambystoma tigrinum)
Amphibians and Reptiles
ly absorbs toxic substances in the air, water, and soil.
Amphibians have complex life cycles and need appropriate
habitat for egg, larval, and adult stages. For
many amphibian and reptile species, seasonal movements
within the landscape are necessary, meaning
that a variety of quality seasonal and transitional
habitats must be available for any given species.
Furthermore, many amphibians and reptiles have
poor dispersal abilities and are often unable to move
to alternate areas when their habitat is disturbed.
Habitat requirements
Amphibians and reptiles can be found in almost all
habitat types, from forests to deserts to grasslands.
Many species use different habitats during different
times of the year. For example, many salamanders
spend most of the year dispersed in the forest,
but they need appropriate wetlands within which to
breed. Some turtles live in water but must travel onto
land to lay their eggs. Many herps hibernate or become
less active during the winter. Hibernation occurs
in hibernacula, which are usually dark, secure,
secluded areas such as rocky outcroppings, crayfish
burrows, mammal burrows, or mud at the bottom of
ponds or wetlands.
Because of their unique life cycles, amphibians often
require both aquatic and terrestrial habitats.
Depending on the species and geographical area, they
may require damp areas (creeks, streams, swamps,
mud puddles, ponds, etc.), moist soil, and/or places to
burrow in order to keep their skin moist. Amphibians
generally breed and lay eggs in wetlands and other
aquatic habitats, some of which exist for only short
periods during the year (after rains or snowmelt),
and then move to terrestrial areas to over winter.
Amphibians use a wide range of terrestrial habitats
adjacent to wetlands and streams, typically consisting
of leaf litter, coarse woody material, boulders, small
mammal burrows, crack in rocks, spring seeps, rocky
pools, and even deserts and desert grasslands.
Some reptiles have very general habitat requirements,
while others have specific ones. Reptiles can live in
terrestrial, aquatic, or riparian habitats. Those that
inhabit riparian habitats are not considered aquatic,
but they are strongly associated with riparian-upland
transitional zones. Some reptiles live and forage
in aquatic habitats most of the year but move to
upland habitats to nest or overwinter. Within grasslands,
woodlands, and wetlands, reptiles require habitats
that provide thermal gradients ranging from cool
shelters to warm basking areas that receive exposure
to full sun. Reptiles also require suitable hibernation
and aestivation habitats to which they can escape during
times of environmental extremes. Thermal, hibernation,
and aestivation habitats may be present in the
form of large woody material, brush piles, rock piles
or outcroppings, animal burrows, or huts. These same
habitats provide nesting habitat for many snakes and
lizards, while nesting habitat for turtles may be found
within areas of loose or sandy soil exposed to full sun
and protected from flooding.
Amphibians and reptiles are a diverse group and their
habitat requirements vary greatly from species to
species. Specific habitat requirements for individual
species are beyond the scope of this leaflet. Table
1 contains general shelter, feeding, and nesting cover
requirements for the major groups of amphibians and
reptiles.
Threats to populations
Some amphibian and reptile populations are on
the decline. For example, populations of western
toads have declined or disappeared from the Rocky
Mountains, Sierra Nevada Mountains, and Cascade
Mountains. Populations of red-legged frogs have
disappeared from parts of California and Oregon.
Populations of Blanchard’s cricket frogs have declined
or disappeared from the Midwest. In addition
to the declines, frogs with multiple, missing, or malformed
legs have been sighted in high numbers in
Canada and the United States. These declines and deformities
are happening around the world. Some of
the documented causes of amphibian and reptile population
declines and deformities are habitat loss and
fragmentation, the alteration of natural disturbance
regimes, predation by and competition with nonnative
and invasive species, disease, environmental pollution,
severe weather, and UV radiation.
U.S. Fish and Wildlife Service
Red-legged frog (Rana aurora)
Amphibians and Reptiles
Table 1 General habitat requirements of North American reptiles and amphibians
Group Foraging habitat Food Breeding habitat
Reptiles
Crocodiles and
alligators
In and around water (lakes,
ponds, swamps, rivers)
Insects, snails, crustaceans, reptiles, frogs,
fish, birds, mammals
Inground or in heaped
vegetation and soil
Lizards In cracks and crevices, in rock or
brush piles, in tree trunks or foliage,
under rocks and logs, among
leaf litter or vegetation, underground
Leaves, fruit, flowers, insects, snails, scorpions,
crabs, other invertebrates, eggs, small
mice, lizards
In soil, under fallen
leaves, in crevices, in
rotting logs
Snakes On the ground, in crevices or burrows,
in rock or brush piles, in
trees, in water
Insects, spiders, snails, slugs, crayfish, crabs,
fish, salamanders, frogs, lizards, turtles,
birds, eggs, small mammals
Upland, riparian, or
wetland areas, burrows,
rotting logs
Turtles and
tortoises
In salt or fresh water, on land
(forests, deserts, grasslands)
Aquatic plants, grasses, berries, fruit, flowers,
leaves, insects, worms, slugs, snails,
crustaceans, other invertebrates, frogs,
snakes, turtles, fish, jellyfish
Well-drained sandy or
loose soil; sometimes
associated with burrows
Amphibians
Frogs and
toads
Under logs, in leaf litter, in damp
rock crevices, in soft soil or mud,
in shrubs and trees, in water, beneath
the soil surface
Tadpoles – algae, plant detritus, leaves, other
tadpoles
Fresh water or moist
areas
Adults – Insects, worms, other invertebrates,
frogs, snakes, lizards, small turtles, small
birds, mammals
Salamanders Cool, damp, shady places, in
caves or burrows, in trees, under
rocks and logs, on ground, in water;
underground
Larvae – insects and other invertebrates,
small crustaceans, tadpoles, zooplankton,
other salamander larvae
Fresh water or moist
areas
Adults – insects, worms, and other invertebrates,
fish, other salamanders, small mice
Amphibians and Reptiles
Habitat loss and fragmentation is a major factor in
the decline of amphibian and reptile species. Many
habitats are disappearing due to human population
growth and development. Of those habitats that do
remain, many are not large enough to support populations
of a given species. If required habitat components
are isolated from each other by agricultural
fields, roadways, or urban development, the animals
may not be able to reach them. Roads pose barriers
that are of particular concern to amphibian and reptile
movements. Often herps are not physically able to
cross roadways, and those that are run the risk of being
killed by vehicles.
The alteration of natural disturbance regimes, such as
fire and flood regimes, can be detrimental to amphibian
and reptile populations. In many ecosystems, these
disturbances help to maintain various stages of vegetative
succession, providing amphibians and reptiles
with their diverse habitat needs. Humans have altered
natural disturbance regimes by suppressing fire, controlling
flood levels, and other means. In the absence
of fire, flooding, or other natural disturbances, natural
habitats become degraded and are less capable of
supporting amphibian and reptile populations.
The introduction of nonnative species is another major
cause of amphibian and reptile decline. Native
species have not evolved with these new predators
or competitors and are often unable to survive in areas
where nonnative species are introduced. For example,
bullfrogs were introduced west of the Rocky
Mountains in the 1800s for human consumption.
These bullfrogs are efficient predators of local amphibians
and some reptiles. Populations of yellowlegged
frogs and other frogs are declining in areas
where bullfrogs are now abundant. Fire ants, introduced
to the southern United States around 1918,
prey on both the eggs and young of reptiles. Fire ants
are considered to be the primary cause of the extirpation
of the Texas horned lizard from parts of its historic
range. In the Southwest, nonnative crayfish have
been implicated in the decline of some amphibian and
aquatic reptile species.
Some amphibian deformities and population declines
can be attributed to diseases caused by viruses, bacterium,
fungi, or parasites. A parasitic fungus has been
identified as the cause of mass mortality in frogs in
the Americas, Australia, and other areas; this fungus
is now thought to be one of the primary suspects responsible
for amphibian declines around the world.
An upper respiratory tract disease is the potential
cause of population declines in desert tortoises in the
southwestern United States and gopher tortoises in
the southeastern United States. Often, nonnative species
will act as vectors for these diseases. For example,
the water fungus Saprolegnia, common in fish
hatcheries, has recently been associated with declines
of amphibian populations.
Amphibian and reptile populations are negatively affected
by environmental pollutants such as heavy
metals, pesticides, and radioactive waste. These pollutants
are suspected of causing deformities and abnormalities
in frogs. Acid rain raises the acidity of water
above the tolerance levels of many amphibian eggs
and tadpoles. This reduces fertilization and can cause
developmental abnormalities. Even though they have
been banned in the United States since 1979, traces
of polychlorinated biphenyls (PCB)—toxic, persistence
pollutants—can be found in air, soil, water,
and animal tissues. Some PCB compounds are similar
to estrogen and can alter the sexual development
of amphibian and reptile embryos. For example, sex
reversal and abnormal gonads have been found in turtles
exposed to PCBs.
Changes in climate, including higher temperatures,
lower soil moisture, longer dry seasons, and more
variability in rainfall, can influence amphibian and
reptile populations. These climate changes can mean
fewer insects available as prey for some species,
changes in activity patterns, depressed immune systems
due to stress, and shorter breeding seasons because
ponds hold less water for shorter periods.
Warmer temperatures impact crocodiles, alligators,
and some turtles whose sex ratios are determined by
nest temperatures during incubation.
High UV radiation resulting from a thinner ozone layer
can cause a variety of problems in amphibians—
DNA mutations, suppressed immune systems, and developmental
problems or death in embryos.
U.S. Fish and Wildlife Service
Collared lizard (Crotaphytus collaris)
Amphibians and Reptiles
Habitat management considerations
Managing habitat for amphibians and reptiles can
take many forms, depending on the landowner’s geographical
location, land use activities, habitat type,
and the target species. Before beginning, landowners
should compile a list of amphibians and reptiles
that occur on their properties and their locations to
determine the priority areas for habitat management.
Landowners are encouraged to consult with local natural
resource professionals and/or herpetologists to
design the best possible habitat management plan for
amphibians and reptiles in their region. Some actions
that can be taken are:
• Provide logs, rocks, and brush piles around wetland
areas and in upland areas.
• Keep a vegetated buffer (minimum 50 feet)
around wetlands and streams.
• Provide upland habitat adjacent to wetland
areas (500 feet or wider if possible).
• Ensure that vegetation is not too dense for herp
movement by promoting a variety of native sedges,
forbs, and warm- and cool-season grasses.
• Avoid introducing nonnative plants or animals,
and control any that have already been introduced.
• Avoid introducing fish to breeding areas.
• Avoid altering natural water levels in wetlands,
rivers, and streams, particularly from the time
herps migrate to overwintering sites through to
spring emergence.
• Maintain shallow water areas or pools for breeding
amphibians.
• Plan any prescribed burning activity to
avoid times when amphibians and reptiles
are particularly active (breeding migrations,
dispersal from hibernacula).
• Avoid using pesticides within 100 yards of
streams or wetlands.
• Limit pesticide use to brands that rapidly decompose
after application.
• Rotate livestock to prevent excessive grazing.
• Keep livestock out of wetlands and riparian
areas.
• Avoid off-road vehicle use.
• Avoid building roads in sensitive areas.
• Build road crossings to help amphibians and
reptiles cross roads safely.
• Avoid fragmenting habitats.
For more information
Partners in Amphibian and Reptile Conservation
(PARC) is an inclusive partnership dedicated to the
conservation of amphibians and reptiles and their
habitats. PARC’s Web site, www.parcplace.org, is an
excellent resource for information on amphibians and
reptiles, their habitat requirements, and habitat management
considerations. In particular, PARC is developing
Amphibian and Reptile Habitat Management
Guidebooks for five geographical regions across the
United States that can be useful to landowners. These
guidebooks can be downloaded from PARC’s Web
site.
U.S. Fish and Wildlife Service
Eastern box turtle (Terrapene carolina carolina)
Amphibians and Reptiles
References
Online sources
AmphibiaWeb: Information on amphibian biology
and conservation. 2005. Overview of amphibian
diseases. http://elib.cs.berkeley.edu/aw/declines/
diseases.html [Accessed 22 June 2005].
The Center for Reptile and Amphibian Conservation
and Management. n.d. http://Herps.ipfw.edu/
[Accessed 17 January 2005].
Natural Resources Conservation Service, Iowa.
2005. Restoring, managing habitat for reptiles,
amphibians. http://www.ia.nrcs.usda.gov/news/
brochures/ReptilesAmphibians.html [Accessed
11 August 2005].
PARC – Partners in Amphibian and Reptile
Conservation. 2004. http://www.parcplace.org/
index.html [Accessed 20 January 2005].
U.S. Geological Survey. 2003. Farm ponds as critical
habitats for native amphibians. http://www.
umesc.usgs.gov/terrestrial/amphibians/
mknutson_5003869.html [Accessed 17 January
2005].
Printed sources
Capula, M. 1989. Guide to reptiles and amphibians of
the world. Simon & Schuster Inc., New York, NY.
Crump, M. 2002. Amphibians, reptiles, and their conservation.
Linnet Books, North Haven, CT.
Conant, R., and J.T. Collins. 1991. A field guide to reptiles
and amphibians of Eastern and Central
North America. Houghton Mifflin Company,
New York, NY.
Daszak, P., L. Berger, A.A. Cunningham, A.D. Hyatt,
D.E. Green, and R. Speare. 1999. Emerging infectious
diseases and amphibian population
declines. Emerging Infectious Diseases
5:735–748.
Gibbons, J.W., D.E. Scott, T.J. Ryan, K.A. Buhlmann,
T.D. Tuberville, B.S. Metts, J.L. Greene, T.M.
Mills, Y. Leiden, S. Poppy, and C.T. Winne. 2000.
Reptiles in decline: the global decline of reptiles,
déjà vu amphibians. BioScience 50:653–666.
Harding, J.H. 1997. Amphibians and reptiles of the
Great Lakes Region. University of Michigan
Press, Ann Arbor, MI.
Jochimsen, D.M., C.R. Peterson, K.M. Andrews, and J.
W. Gibbons. 2004. A literature review of the effects
of roads on amphibians and reptiles and
the measures used to minimize those effects.
Idaho Fish and Game Department and USDA
Forest Service.
Johnson, T.R. 1987. The amphibians and reptiles of
Missouri. Missouri Department of Conservation,
Jefferson City, MO.
Kenney, L.P., and M.R. Burne. 2000. A field guide to
the animals of vernal pools. Massachusetts
Division of Fisheries and Wildlife, Westborough,
MA, USA and Vernal Pool Association, Reading,
MA.
Kingsbury, B., and J. Gibson. 2002. Habitat management
guidelines for amphibians and reptiles of
the Midwest. Partners in Amphibian and Reptile
Conservation, Midwest Working Group, Fort
Wayne, IN.
Knutson, M.G., W.B. Richardson, D.M. Reineke, B.R.
Gray, J.R. Parmelee, and S.E. Weick. 2004.
Agricultural ponds support amphibian populations.
Ecological Applications 14:669-684.
Lehtinen, R.M., S.M. Galatowitch, and J.R. Tester.
1999. Consequences of habitat loss and fragmentation
for wetland amphibian assemblages.
Wetlands 19:1-12.
Maxell, B.A. 2000. Management of Montana’s amphibians:
a review of factors that may present a risk
to population viability and accounts on the identification,
distribution, taxonomy, habitat use,
natural history, and the status and conservation
of individual species. Report to USFS Region 1,
Order Number 43–0343–0–0224. Wildlife Biology
Program, University of Montana, Missoula, MT.
Petranka, J.W. 1998. Salamanders of the United States
and Canada. Smithsonian Institution Press,
Washington, DC.
Pough, F.H., R.M. Andrews, J.E. Cadle, M.L. Crump,
A.H. Savitzky, K.D. Wells. 2004. Herpetology.
Pearson Prentice Hall, Upper Saddle River, NJ.
Schneider, R.L., M.E. Krasny, S.J. Morreale. 2001.
Hands-on herpetology: exploring ecology
and conservation. National Science Teachers
Association Press, Arlington, VA.
Amphibians and Reptiles
Semlitsch, R.D., and J.R. Bodie. 2003. Biological criteria
for buffer zones around wetlands and
riparian habitats for amphibians and reptiles.
Conservation Biology 17:1219-1228.
Shea, G. 2002. Reptiles & amphibians. Fog City Press,
San Francisco, CA.
Amphibians and Reptiles
Primary authors: Raissa Marks, Wildlife Habitat Council. Drafts reviewed by: Rob Pauline, Wildlife Habitat
Council; Charlie Rewa, Natural Resources Conservation Service; Jennifer Anderson-Cruz, Natural
Resources Conservation Service; Linda Weir, North American Amphibian Monitoring Program; Bob
Herrington, Georgia Southwestern State University; Christopher Jenkins, Idaho State University; Charles
Peterson, Idaho State University; and Randy Babb, Arizona Game and Fish Department.
www.nrcs.usda.gov
Wildlife Habitat Council
8737 Colesville Road, Suite 800
Silver Spring, MD 20910
(301) 588-8994
The mission of the Wildlife Habitat Council
is to increase the amount of quality wildlife
habitat on corporate, private, and public land.
WHC engages corporations, public agencies,
and private, nonprofit organizations on a
voluntary basis as one team for the recovery,
development, and preservation of wildlife
habitat worldwide.
www.wildlifehc.org
© 1988 WHC
WILDLIFE HABITAT COUNCILSM
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