Herpetology

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Herpetology

  1. 1. Herpetology What is it?
  2. 2. Herpetology is the study of reptiles and amphibians
  3. 3. Why study herpetology?Important implications for conservation,research and education o Amphibians are excellent bio-indicators for environmental quality and change. o Snake venom is proving to be very useful to the medical field (dissolving blood clots in heart attack and stroke victims).
  4. 4. Types of Amphibians• Frogs• Toads• Salamanders• Caecilians
  5. 5. Amphibians as Bio-indicators•Because amphibians absorb waterthrough their skin, they are often thefirst to suffer the effects of water orenvironmental pollution.•Nearly 1/3 (32%) of amphibiansworldwide are threatened•Nearly 168 species are believed tohave gone extinct•43% of species are in decline
  6. 6. Major reasons for decline:•Habitat destruction•Chytridiomycosis (a fungal disease)Other factors:•Introduction of non-native species•Over-exploitation (pet trade)•Climate change; amphibians are very sensitive tosmall temperature changes, which can affect theirbreeding habits, reproduction and immune response•UV-B radiation (due to decreases in stratosphericozone layer)•Chemical contaminants (pesticides, heavy metals,acidification and nitrogen based fertilizers)
  7. 7. Amphibians: Means “double life”• Have gills and lungs• Are cold-blooded• Most lay soft, gel-covered eggs (exceptions include the Fire Salamander, some African Toads and most species of Caecilians)• Are vertebrates• Many have toxic secretions as defense
  8. 8. Common Salamanders ofShenandoah River State Park
  9. 9. Spotted Salamander
  10. 10. Jefferson Salamander
  11. 11. Dusky Salamander
  12. 12. Red-backed Salamander
  13. 13. Marbled Salamander
  14. 14. Valley and Ridge Salamander
  15. 15. Slimy Salamander
  16. 16. Four-toed Salamander
  17. 17. Newts:• All newts are salamanders, but not all salamanders are newts.• Newts have three distinct life stages – Aquatic larvae (tadpole) – Terrestrial adult (eft): 1 to 3 years – Aquatic adult (newt)
  18. 18. Red-spotted Newt (adult)
  19. 19. Eft(juvenile Red-Spotted Newt)
  20. 20. Salamander Life Cycle Egg LarvaeAdult Juvenile
  21. 21. Salamander Biodiversity:• Salamanders can be aquatic, terrestrial, or a mixture of both. Living in diverse habitats cause different species to use different types of respiration.Types of Respiration:• External gills• Lungs• Skin/cutaneous respiration (all salamanders can do this)
  22. 22. Aquatic Habitat:• Larvae are born in water using external gills• Juveniles and adults breathe through external gills if retained, skin if not• Breathing through skin requires constant moisture, easy if aquatic (example: Mudpuppy)
  23. 23. Terrestrial Habitat:• Most terrestrial salamanders lay eggs in the water that hatch into aquatic larvae that later crawl out on land.• A few species lay eggs on land that hatch into juveniles.• Juveniles and Adults breathe through skin and lungs if present• If lungs are lacking the salamander must live in a moist area to breathe through its skin (ex.: Spotted Salamander)
  24. 24. Semi-Aquatic:•Larvae are born in water and breath throughexternal gills• Juveniles crawl out on land and breathe usinglungs.•Adults return to the water using skin to breathe,and occasionally venture on land using lungs.(example: Eastern Red Spotted Newt)
  25. 25. What they Eat: Mostly insects, however, any animal they can fit intheir mouth is fair game (including smaller salamanders!) Aquatic salamanders use chemical signals to track preyTerrestrial salamanders use vision to detect movementWhat Eats Them: Birds and snakes on land Fish and turtles in the water
  26. 26. Salamander eggs have a firm, outer jelly coating that encases the eggs.These are Spotted salamander eggs.
  27. 27. Common Frogs and Toads ofShenandoah River State Park
  28. 28. American Bullfrog
  29. 29. Green Frog
  30. 30. How to tell the difference…
  31. 31. Pickerel Frog
  32. 32. Southern Leopard Frog
  33. 33. Differences between the twoPickerels have a double row Southern Leopards have irregular spots of spots on their backs and a white spot on the eardrum
  34. 34. American Toad
  35. 35. Fowler’s Toad
  36. 36. Easy way to tell the difference…
  37. 37. Wood Frog
  38. 38. Spring Peeper
  39. 39. Northern Cricket Frog
  40. 40. Gray Treefrog
  41. 41. Upland Chorus Frog
  42. 42. Life cycle of Frogs and Toads
  43. 43. On frog eggs, you can easily see the contour of each individual egg on the outside of the mass. This is a Pickerel Frog egg mass.
  44. 44. Toad eggs
  45. 45. Reptiles
  46. 46. • Reptiles are vertebrates.• Reptiles are covered in scales or have scutes.• Reptiles breathe with lungs.• Most reptiles lay hard-shelled eggs. Some reptiles, like pit vipers, give birth to live young.• Almost all reptiles are cold-blooded. (One exception is the leatherback sea turtle, which can regulate its body temperature to some degree.)
  47. 47. Snake Characteristics• Snakes have clear scales over their eyes so they do not have eyelids forblinking or closing their eyes.•Snakes do not have ears so they do not hear as we do. They feelvibrations.•Snakes use their tongues for smelling using the Jacobson’s organ•The pits on venomous snakes detect thermal infrared radiation. Thepits respond to subtle thermal fluctuations in the environment andallows for an accurate measurement of the distance of a heat source.•Non-venomous snakes do not have fangs, but have rows of pointedbackward-curved teeth•A snake’s jaws can come apart so that they can eat large prey.•Snakes will shed their skin several times a year as they grow.
  48. 48. Venomous Snakes in Virginia
  49. 49. Northern Copperhead
  50. 50. Timber Rattlesnake
  51. 51. Water SnakesNorthern Water Snake Queen Snake
  52. 52. Black Racer Eastern Ratsnake
  53. 53. Eastern Hognose Snake
  54. 54. Northern Ring-necked Snake
  55. 55. Rough Green Snake
  56. 56. Eastern Worm Snake
  57. 57. Milk Snake
  58. 58. Eastern Garter Snake
  59. 59. Common Ribbon Snake
  60. 60. Northern Red-bellied Snake
  61. 61. Eastern Smooth Earth Snake
  62. 62. Northern Brown Snake
  63. 63. Red Corn Snake
  64. 64. Turtle Characteristics• Do not have teeth• Usually omnivores• Lay eggs and leave them. Many eggs are eaten by predators, such as raccoons, skunks, coyotes, dogs, crows and snakes.• Box turtle populations are in decline due to habitat loss, road mortality and collection by humans.
  65. 65. Aquatic Turtles Eastern Snapping Turtle
  66. 66. Eastern Painted Turtle
  67. 67. Eastern Musk Turtle
  68. 68. Wood Turtle (endangered)
  69. 69. Red-bellied Cooter
  70. 70. Spotted Turtle(High conservation need)
  71. 71. Box Turtle(terrestrial)
  72. 72. Lizards of the Park Common Five-lined Skink
  73. 73. Broad-headed Skink Skinks differ from other lizards in that they have shorter limbs and do not have a defined neck.
  74. 74. Eastern Fence Lizard

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