Transcript Amphibians and Reptiles: An Introduction to Herpetofauna

Amphibians and Reptiles:
An Introduction to
Herpetofauna
Compiled by the Davidson College
Herpetology Laboratory
Edited for Virginia by Mike Clifford, Virginia Herpetological Society
Eastern Hognose Snake
Green Treefrog
Amphibians and Reptiles
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Ectothermic
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Use outside energy
sources to maintain body
temperature for
metabolism and
regulatory functions
Fence
Lizard
River Cooters
Timber Rattlesnake
Northern
Watersnake
Cryptic
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Very difficult to detect
even though they can be
highly abundant
Timber Rattlesnake
Queen Snake
Tetrapods
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Snakes have evolutionarily
lost their legs
Humans evolved from
one of the same ancestors
of extant reptiles
Non-Tetrapod
Vertebrates
Frogs
Salamanders
Caecilians
Reptiles
Birds
Mammals
Rainbow Snake
Adapted from the WhoZoo
Amphibians and Reptiles
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Very important to the ecosystem
Prey and Predator
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Prey item for animals including
raccoons, opossums, and birds
Prey upon insects, mice, and rats
Bio-indicator
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Green Salamander
An animal that can indicate the
health of an environment by its
population structure and abundance
Ringneck Snake
Spring Salamander
Eastern Spadefood Toad
Eastern Spiny Softshell Turtle
Amphibians
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78 Species in Virginia
(51 salamanders & 27 frogs & toads)
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SE U.S. - greatest salamander
diversity in the world!
Huge Biomass
Biomass: Total weight of all
amphibians in an area
 One isolated wetland
produced 3 tons of
amphibians
Spotted Salamander
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Three-Lined Salamander
Southern Leopard Frog
Amphibian Characteristics
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Permeable skin
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Good olfaction
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Permeable: Allows the transfer of
oxygen and carbon dioxide to allow
respiration
Can allow the uptake of chemicals
in the environment
Green Frog
Olfaction: Sense of smell
Prey upon:
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Insects, other amphibians, anything
small enough to fit into their
mouths, even mice
Spring Salamander
Frogs
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Tadpoles lose tails and grow legs as they
metamorphose
True Frogs
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Rana
Tree Frogs
Hyla
 Toe pads
Southern Leopard Frog
Bull Frog
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Spring Peeper
Upland Chorus Frog
Green Tree Frog
Grey Tree Frog
Toads
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Similar to frogs
Tadpoles lose tail and grow legs
as they metamorphose into adults
Less dependent upon water than
frogs
Have warty skin
Paratoid Glands:
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American Toad
Glands behind the eye that secrete
toxin
Fowler’s Toad
Salamanders
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Plethodontids: No lungs
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Spring Salamander
Ambystomatids: Lungs
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Obligate, aerobic respiration through the
skin
Facultative, aerobic respiration through
the skin
Hellbenders
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Grow to 2 feet in the USA, but up to 5
feet in Japan
Hidden gills
Marbled Salamander
Photo by Kristen Cecala
Hellbender
Amphibian Breeding Locations
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Streams
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Wetlands
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Adults utilize upland habitat for feeding
Use stream for breeding, larval period, and
occasional foraging
Spring Salamander Larva
Adults live and feed in upland habitat
Return to wetlands to breed and undergo larval
periods
Terrestrial
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Adults never require water for reproduction
No larval stage
Utilize moisture under logs and leaf litter
Redback Salamander
Caecilians
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Live in the tropics
Leg-less and blind
Look very similar to a worm
Caecilians
Amphibian Life Cycle
Upland Chorus Frog
Frog eggs
Pine Woods Tree Frog Tadpole
Spring Peeper calling
Cricket Frog
Spring Peeper
Tadpole/Metamorph
Amphibian Defense Mechanisms
American Toad
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Toxin in skin
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Toads and Newts
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Producing large numbers of
offspring
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Producing noisy squawks
when attacked
Red-Spotted Newt
Green Frog Tadpole
Reptiles
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62 species in Virginia from 3 groups
(30 snakes, 10 lizards including one introduced, 22 turtles)
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Antarctica the only continent without reptiles
Snakes have no legs, but still tetrapods
Evolutionary loss of legs
 Boas still maintain a pelvic girdle
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Broadhead Skink
Eastern Painted Turtle
Copperhead
Reptiles
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First vertebrates to become independent of
water for reproduction
Some reptiles have reverted to aquatic lifestyles,
but still reproduce without water
Sea Snakes
 Snapping Turtle
 Sea Turtles
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Snapping Turtle
Reptiles
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Ectothermic
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Maintain a constant
temperature range
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Maintained by
basking, movement,
and shivering
Brummation =
hibernation
Yellow-bellied Slider
Crocodilians
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American Alligator – not native to Virginia but
is found just to the south in North Carolina
American Alligators
Turtles
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Temperature sex determination
Vertebrae integrated into shell
No teeth: Beak similar to a bird
Omnivorous
3 habitats
Marine
 Freshwater
 Terrestrial
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Eastern Painted Turtle
Loggerhead Sea Turtle
Box Turtle
Snapping Turtle
Squamata
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Snakes and lizards
Jacobson’s organ
Olfactory organ
 Tongue flicks out of the mouth and moves
chemicals in the air to the organ
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Northern Copperhead
Extremely movable jaw
Rough Green Snake
Scarlet Kingsnake
Six-line Racerunner
Lizards
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Extremely variable and diverse
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Many endemic species
Leg-less Lizards
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Five-lined Skink
Glass Lizards or Jointed Snakes
Lizards have eyelids and ear
holes that snakes do not
Slender Glass Lizard
Fence Lizard
Ground Skink
Snakes
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30 species in Virginia
3 venomous species
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Copperhead, Cottonmouth,
Timber Rattlesnake.
Scarlet Kingsnake –
non-venomous
Most species are nonvenomous
Ringneck Snake – non-venomous
Copperhead - venomous
Black Rat Snake – non-venomous
Snakes
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All lack legs
Lack ear openings
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Hear vibrations through the
ground
Eastern Hognose
Snake
Shed their skin to grow
Either lay eggs or give birth to
live young
Black Racer
Redbelly Watersnake
Ringneck Snake
Rainbow Snake
Snake Feeding
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Entirely carnivorous
Swallow prey whole
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Can eat prey much larger than
themselves
Some use venom to immobilize prey
Some constrict their prey
Some actively forage for prey
Some sit and wait for prey to
approach them
Eastern Cottonmouth eating a mouse
Northern Watersnake eating a fish
Snake Defense Mechanisms
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Crypsis: Staying camouflaged
When detected:
Flee, musk, gape, rattle
 When these do not work, snakes may
strike
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This occurs only when a snake feels
threatened and has no other option to
protect itself
Brown Watersnake
Cottonmouth
Northern Copperhead
Eastern Hognose Snake
Conservation
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Many amphibians are in
decline
32% of amphibians
endangered versus 12% of
birds or 23% of mammals
43% of amphibian
populations are declining
Few populations are known
to be increasing
Grey Tree Frog
Red Salamander
Bog Turtle
Eastern Kingsnake
Causes of Decline
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Habitat destruction
Disease
Pollution
Over-exploitation
Climate change
Invasive species
How many are human caused?
What can you do?
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Enjoy finding and observing
amphibians and reptiles
Don’t keep wild amphibians and
reptiles as pets
Don’t kill snakes
Make sure you know a venomous
species looks like before handling
snakes, and NEVER touch or
threaten a venomous snake
Don’t release any amphibian or
reptile pet into the wild
Questions?
Corn Snake