Herpetology for Master Naturalists · 2018-04-03 · Herpetology for Master Naturalists (condensed)...

Herpetology for Master Naturalists (condensed)

Henry M. Wilbur

salamander@virginia.edu

Outline of Topics • Taxonomy of reptiles and amphibians

• Key characteristics used to identify reptiles and amphibians

• The natural history and basic biology of reptiles and amphibians

• The diversity and distribution of reptiles and amphibians in Virginia

• Some common reptiles and amphibians occurring in the local ecosystems

• The role of reptiles and amphibians in Virginia ecosystems

Topics (Continued)

• The adaptations of reptiles and amphibians and how these relate to environmental factors

• The basic principles of reptile and amphibian management

• Threats and/or issues relating to reptiles and amphibians in Virginia

• Appropriate techniques and methods for studying reptiles and amphibians

• Rare or special species that indicate habitat qualities

Added Value

• Bibliographic Resources

• Web Resources

• Local Sites

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Number

Taxonomic Diversity of Virginia Herps

Families

Genera

Species

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5

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35

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45

Species

Geographical Species Density

Tidewater

Piedmont

Mountins

Taxonomy • Taxonomy – Nomenclatural system for

classifying evolutionary units.

– Latin binomials

• Class Amphibia

• Order Anura

• Family Hylidae

• Genus Pseudacris

• Species crucifer

–Genus always capitalized, species never

–Common name: Spring Peeper

Systematics • Systematics – The quest to develop a

classification that reflects the evolutionary history of lineages.

• Tools of the systemacist

– Morphology

– Development

– Genetics

– Phylogeny Reconstruction

– The Web http://tolweb.org/tree/

Phylogeny of the Extant Tetrapoda

Mammals Amniota Reptiles and Birds

Amphibia Frogs and Salamanders

Tetrapoda After: http://tolweb.org/Terrestrial_Vertebrates/14952

Evolved in the Devonian from lobe-finned fishes

Phylogeny of Living Amphibians

Salientia (Frogs and Toads)

Caudata (Salamanders and Newts)

Gymnophiona (Caecilians)

© 2005 Teague O'Mara Lissamphibia

Characteristics of Amphibians • Anura – Tailless jumping machine

–Nine or fewer presacral vertebrae

–Postsacral vertebrae fused as urostyle

–Radius and ulna fused as radioulna

– Tibia and fibula fused as tibiofibula

• Caudata

– Tail in larva, juveniles, and adults

– Two pairs of limbs

–Many technical skeletal characters

Frogs Families of Virginia

• Scaphiopidae – Spadefoot Toad

• Bufonidae - American Toad

• Microhylidae – Narrow-mouthed Toad

• Hylidae – Spring Peeper

• “Ranidae” - Bullfrog

The Anuran Life Cycle

Egg

Larva (Tadpole)

Juvenile

Adult

Anuran Larvae • Filter-feeders

• Rasping mouthparts

• Coiled intestine

Role of Anurans in Aquatic Food-webs

Tadpoles

Periphyton Phytoplankton

Fish Salamanders Snakes Insects Birds

Role of Anurans in Terrestrial Foodwebs

• Juvenile and Adult Frogs Eat Insects

–Adult Bullfrogs eat Crayfish and Smaller frogs

• Juvenile and Adult Frogs Are Eaten By Many mesopredators

–Mammals: Raccoons, skunks, mink, etc.

– Snakes: Gartersnakes, watersnakes, etc.

–Birds: Herons, hawks, grebes, etc.

Species of Frogs in Albemarle County

• Toads

–American Toad

–Fowler’s Toad

• Tree Frogs

–Upland Chorus Frog

–Spring Peeper

–Grey Treefrog

True Frogs of Albemarle County

• True Frogs

–Bullfrog

–Green Frog

–Leopard Frog

–Pickerel Frog

–Wood Frog

Optimal Timing of Metamorphosis

The balance between growth opportunities and mortality risk

Grey Tree Frog

Flash Colors

Turbo Tadpoles

Range of Gray Treefrog

Range of Woodfrog

Salamander Families of Virginia

• Sirenidae: Siren

• Cryptobranchidae: Hellbender

• Necturidae: Necturus (mudpuppy)

• Salamandridae: Newts

• Ambystomatidae: Mole salamanders

• Amphiumidae: Amphiuma (Conger eel)

• Plethodontidae: Woodland salamanders

Salamander Life Cycles

• Primitive Condition: Aquatic Egg →

Aquatic Larva → Terrestrial Juvenile → Terrestrial Adult

• Direct Development: Female lays a clutch

of a few large eggs in a terrestrial site where she attends them. The larval stage and metamorphosis are completed within the egg capsule.

Salamanders of Albemarle County

• Salamandridae

–Red-spotted Newt

• Ambystomatidae

–Marbled Salamander

–Spotted Salamander

• Plethodontidae - lungless

Plethodontids of Albemarle County

• Plethodontidae

– Red-backed Salamander

– Slimy Salamander

– Two-lined Salamander

– Northern Dusky Salamander

– Seal Salamander

– Mud Salamander

– Red Salamander

– Spring Salamander

Red-spotted Newt

Egg

Larva Paedo-morph

Eft Adult

Adult

Marbled Salamander Life Cycle

• Adults move to dried pond basins in early fall

• Courtship is on land in September

• Females lay eggs and attend them in fall

• Pond floods with autumnal rains

• Larvae hatch when flooded

• Larvae winter in pond

• Larvae metamorphose and leave pond in June

Spotted Salamander Eggs

Spotted Salamander Life Cycle

• Males move to ponds soon after ice leaves

• Females move to pond early spring rain

• Courtship and egg deposition in water

• Males and females leave following rain

• Eggs hatch late spring

• Larvae metamorphose and leave pond in mid summer

Tiger Salamanders are Endangered in Virginia and other states on the East Coast

Red-backed Salamander

Plethodon cinereus complex

• P. shenandoah – Stony Man, Hawksbill, The Pinnacles of SNP.

• P. hubricti – Peaks of Otter

• P. nettingi – Cheat Mountain, WV

• P. cinereus – widespread in surrounding habitats

Eggs of the Two-lined Salamander

Embryos of the Two-lined Salamander

Amphibian Conservation Biology • Threats

–Habitat Loss (breeding sites, foraging areas)

–Pollution (pesticides)

–Disease (chytrid fungus, ranovirus)

–Predation (fish, feral cats)

• Remediation

–Wetland restoration

–Cover habitats

– Fish removal

Natural Populations

Methods to Study Amphibians:Experimental Populations

Extant Groups of Amniotes

• Birds and Crocodylians

• Turtles and Tortoises

• Squamates (Lizards and Snakes)

• Tuatara

• Mammals

Phylogeny of the Amniotes:The Terrestrial Vertebrates

Synapsida (Mammals)

Anapsida: Testudines (Turtles)

Romeriida: Diapsida Birds, Lizards, Snakes

http://tolweb.org/Amniota/14990

The Amniotic Egg

Turtles of Virginia • Chelydridae

– Snapping Turtle

• Kinosternidae

– Mud Turtle

– Stinkpot

• Emyidae

– Painted Turtle

– Eastern Box Turtle copyright © E. S. Gaffney

Temperature-Dependent Sex Determination

Painted Turtle in Nebraska

The sex of many turtles, lizards, snakes, and alligators is determined by temperature during a critical period of development in the nest.

Conservation Biology of Turtles

• Threats

– Habitat Destruction (wetlands and nesting sites)

– Highways

– Pollution by pesticides

– Climate Change?

• Remediation

– Natural areas

– Education

Phylogeny of the Diapsida

Sauria

Archosauromorpha (Crocodilians and Birds)

Lepidosouromorpha (Lizards, Snakes, Tuatara)

http://tolweb.org/Diapsida/14866

Diapsids have a large suborbital fenestra

Dinosaurs

Lizards of Albemarle County • Teiidae

– Six-lined Racerunner

• Phrynosomatidae

– Eastern Fence Swift

• Scincidae

– Five-lined Skink

– Broad-Headed Skink

Range of Broad-headed Skink

Conservation Biology of Lizards

• Threats

– Habitat Destruction

– Feral Cats

– Pesticides

• Remediation

– Natural Areas

Poisonous Snakes of Albemarle County

• Crotalidae

– Copperhead

– Timber Rattlesnake

Geographic Range of Cottonmouth

Range of Northern Watersnake

First Aid for Snakebite

• Stay calm

• Treat for Shock

• Elevate bitten limb

• Get Patient to a Hospital for Antivenin

Nonpoisonous Snakes of Albemarle • Colubridae

– Black Ratsnake

– Black Racer

– Corn Snake

– Milk Snake

• Dipsadidae

– Wormsnake

– Ring-necked Snake

• Natricidae

– Ribbon Snake

– Garter Snake

– Northern Watersnake

Hog-nosed Snake

Hog-nosed Snake

“Dead” Hog-nosed Snake

Conservation Biology of Snakes

• Threats

– Habitat Destruction

– Human Ignorance

• Remediation

– Natural Areas

– Education

Educational Resources

• Bibliographic

• Web

– Tree of Life Project http://tolweb.org/tree/

– http://www.ucmp.berkeley.edu/taxa/verts/diapsida.php

– http://www.cnah.org/

• Local Experts (UVa Biology)

– Butch Brodie

– Bob Cox

Find More Information www.dgif.state.va.us/

Books worth having

• Atlas of Amphibians and Reptiles in Virginia by Joseph C. Mitchell and Karen K. Reay

• The Reptiles of Virginia by Joseph C. Mitchell

• Peterson’s Field Guide to Reptiles and Amphibians by Robert Powell and Roger Conant 2016.

• Books on each group by Whit Gibbons