Nature Net’s Pre- and Post-Field Trip Materials
Subject: Reptiles and Amphibians
Level: Middle School
Introduction
Reptiles and Amphibians (a.k.a. ‘Herps’) are often grouped together because they look similar to one another. However, even though they’re often grouped together, they’re really quite different! While amphibians (usually) go through metamorphosis to reach the adult stage, reptiles’ young hatch as tiny versions of the adults. In Wisconsin, the most common reptiles and amphibians are frogs, toads, turtles, snakes, and salamanders.
Vocabulary:
Cold-blooded: Not being able to internally maintain a constant body temperature. Amphibians and reptiles (along with fish and all invertebrate animals) are cold-blooded animals raise their body temperature by warming themselves in the sun. As their body temperature rises, they gain energy and become more active.
Metamorphosis: A process that many amphibians go through as they change from juveniles to adults. For instance, frogs grow from eggs to tadpoles, but they don’t stop there! They then develop from tadpoles to adult frogs.
Reptile: Reptiles have scaly skin and no hair. They’re always cold-blooded, and usually lay eggs on land. Reptiles do not go through metamorphosis. Like humans, their young hatch as tiny versions of the adults. Lizards, snakes, and turtles are examples of reptiles. Reptiles have special ways of living in many different places on earth (adaptations).
Amphibian: Amphibians usually have smooth skin, and they lay jelly-coated eggs in water. Most amphibians go through metamorphosis. Most amphibians live part of their life in the water and part on land. Frogs and salamanders are good examples of amphibians.
Concepts
Though reptiles and amphibians are called "cold-blooded," that doesn’t mean their blood is cold! It just means they can’t maintain their temperature internally (thermoregulation). That’s why you see frogs and lizards sunning themselves during the day- they’re soaking in the heat! The blood inside of cold-blooded animals ‘takes on’ the temperature of its surroundings.
Most herps (reptiles and amphibians) shed their skin - usually several times in one year. Snakes are an example of a herp that sheds its skin often.
And, get this! Some herps use their tongues to smell their surroundings. Inside its mouth, some herps have a Jacobson’s organ, which flicks out and collects molecules from the air. When the molecules touch the tip of the Jacobson’s organ, the herp collects the information.
Scientists have traced herps back to the Devonian Period- about 360 million years ago! Amphibians, then, were some of the first vertebrates to "colonize" the land.
Pre-Trip Activities
Have each student choose a different reptile or amphibian and research as much as possible about it—its physical characteristics, habitat, range, speed, size, prey, predators, behavior, biology, and any associated legends or stories. When their research is complete, have each student create a page for a "field guide to herps." Their pages should include a drawing of their herp as well as a description of everything they uncovered in their research. In addition, each student should measure out a length of adding machine tape or string that corresponds to the average length of the snake he or she has researched. The students can then attach their "bookmark" to the bottom of their illustrated description.
Field Trip Activities
While you’re outside learning about herps, bring along your "field guide" and see how many of them you can find.
Post-Trip Activities
A herpetologist is a person who studies reptiles and amphibians for a living—they know almost everything there is to know about herps. Divide your students into small groups and send each group on a fact-finding mission. Assign each group a different "basic herpetology concept." These may include, among others, the latest first aid for snake bites, the uses of snake venom, reptiles of North America, reptile or amphibian (a specific one!) reproduction, and snake biology. Ask each group to investigate their herpetology concept and prepare a presentation for the rest of the class. Alternately, you can ask the groups to prepare an illustrated written report, which can then be combined with the materials developed in the "Herpatology Field Guide" activity above.
Have a herp count on your school grounds or at a nearby pond. The Audubon Society http://www.audubon.org/
may be able to help your classroom locate a great, near-by wetland to visit.Great Resources for More Information:
Ranger Rick’s Nature Scope, Let’s Hear it for Herps!, National Wildlife Federation, 1987.
Discovering Frogs and Toads, Linley, Mike. Bookwright, 1986.