Transcript High School
Amphibians and Reptiles: An Introduction to Herpetofauna Compiled by the Davidson College Herpetology Laboratory Eastern Hognose Snake Green Treefrog Amphibians and Reptiles Ectothermic Use outside energy sources to maintain body temperature for metabolism and regulatory functions Fence Lizard River Cooters Timber Rattlesnake Northern Watersnake Cryptic Very difficult to detect even though they can be highly abundant Timber Rattlesnake Eastern Diamondback Rattlesnake Tetrapods 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 Eastern Diamondback Rattlesnake Adapted from the WhoZoo Amphibians and Reptiles Very important to the ecosystem Prey and Predator Prey item for animals including raccoons, opossums, and birds Prey upon insects, mice, and rats Bio-indicator 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 Green Anole Amphibians 88 Species in North Carolina Highest 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 Three-Lined Salamander Southern Leopard Frog Amphibian Characteristics Permeable skin Good olfaction 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: Insects, other amphibians, anything small enough to fit into their mouths, even mice Spring Salamander Frogs Tadpoles lose tails and grow legs as they metamorphose True Frogs Rana Tree Frogs Hyla Toe pads Southern Leopard Frog Bull Frog Spring Peeper Upland Chorus Frog Green Tree Frog Grey Tree Frog Toads 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: American Toad Glands behind the eye that secrete toxin Fowler’s Toad Salamanders Plethodontids: No lungs Spring Salamander Ambystomatids: Lungs Obligate, aerobic respiration through the skin Facultative, aerobic respiration through the skin Hellbenders 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 Streams Wetlands 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 Adults never require water for reproduction No larval stage Utilize moisture under logs and leaf litter Redback Salamander Caecilians 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 Toxin in skin Toads and Newts Producing large numbers of offspring Producing noisy squawks when attacked Red-Spotted Newt Green Frog Tadpole Reptiles 70 species in North Carolina from 4 groups Antarctica the only continent without reptiles Snakes have no legs, but still tetrapods Evolutionary loss of legs Boas still maintain a pelvic girdle Copperhead American Alligator Broadhead Skink Eastern Painted Turtle Reptiles First vertebrates to become independent of water for reproduction Some reptiles have reverted to aquatic lifestyles, but still reproduce without water Sea Snakes Swamp Snake Snapping Turtle Sea Turtles Black Swamp Snake Snapping Turtle Reptiles Ectothermic Maintain a constant temperature range Maintained by basking, movement, and shivering Brummation = hibernation Yellowbelly Slider Crocodilians American Alligator Osteoderms Temperature Sex Determination Sex of offspring determined by the temperature at which eggs are incubated American Alligators Turtles Temperature sex determination Vertebrae integrated into shell No teeth: Beak similar to a bird Omnivorous 3 habitats Marine Freshwater Terrestrial Eastern Painted Turtle Loggerhead Sea Turtle Box Turtle Snapping Turtle Squamata Snakes and lizards Jacobson’s organ Olfactory organ Tongue flicks out of the mouth and moves chemicals in the air to the organ Extremely movable jaw Green Anole Rough Green Snake Scarlet Kingsnake Eastern Diamondback Rattlesnake Lizards Extremely variable and diverse Many endemic species Leg-less Lizards 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 37 species in North Carolina 6 venomous species Eastern Diamondback Rattlesnake - venomous Scarlet Kingsnake – non-venomous Copperhead, Cottonmouth, Coral Snake, Timber Rattlesnake, Eastern Diamondback Rattlesnake, and Pigmy Rattlesnake Most species are nonvenomous Ringneck Snake – non-venomous Black Rat Snake – non-venomous Snakes All lack legs Lack ear openings 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 Coachwhip Snake Feeding Entirely carnivorous Swallow prey whole 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 Diamondback Rattlesnake eating a Cottontail Rabbit Scarlet Kingsnake eating a Green Anole Snake Defense Mechanisms Crypsis: Staying camouflaged When detected: Flee, musk, gape, rattle When these do not work, snakes may strike This occurs only when a snake feels threatened and has no other option to protect itself Cottonmouth Eastern Diamondback Rattlesnake Eastern Hognose Snake Brown Watersnake Conservation 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 Habitat destruction Disease Pollution Over-exploitation Climate change Invasive species How many are human caused? What can you do? 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 poisonous species looks like before handling snakes, and NEVER touch or threaten a poisonous snake Don’t release any amphibian or reptile pet into the wild Questions? Corn Snake