Slithering Snakes (GMHDRNC)

Summary:

This hands-on program deals with the snake species in Arkansas and reminds participants why snakes are important to the ecosystem.

Grade Level:

K - 12

Recommended Setting:

Indoor or outdoor classroom

Outdoor Activity:

No

Location:

Governor Mike Huckabee Delta Rivers Nature Center, Pine Bluff

Contact:

Education Program Coordinator, 870-534-0011

 

Duration:

45 minutes - 1 hour

Suggested Number of Participants:

10 - 30

Objectives:

  • Learn the physical and behavioral characteristics of snakes.
  • Understand the similarities and differences of venomous and nonvenomous snakes.
  • Explore habitat requirements for the snakes used in class
  • Understand the importance of snakes to their ecosystems

Key Terms*:

Cold-blooded

Jacobson’s organ

Omnivorous

Oviparous

Ovoviviparous

Scale

Venomous

*See glossary for definations

Materials:

Live animals

Snake skeleton

Snake skins

Background:

There are about 2700 species of snakes worldwide, of these about 600 are venomous.  Snakes are cold-blooded, scale-covered, (mostly) egg-laying animals that spend most of their lives on land. They are a misunderstood group, often killed due to fear rather than reason. In actuality, snakes are interesting and helpful, especially in controlling pests.

Procedure:

  1. Begin by discussing the unique physical characteristics of snakes. Snakes don’t have ears; they use their bodies to feel vibrations of approaching animals. Since they don’t see well, snakes rely on their sense of smell by using their tongues. When a snake flicks its tongue, it actually smells. By touching the forked ends to openings in the top of their mouths, they can determine what sorts of prey are near and information about their surroundings. These holes are called the Jacobson’s organ.
  2. Explain that while most snakes are oviparous or egg layers, some are a little different. Some snakes, such as the diamondback rattlesnake, reproduce ovoviviparously, where the female snake carries the eggs within until they hatch, giving the appearance of live births. 
  3. Of all the snakes in the world, only 10 percent are venomous. Discuss the difference between venom and poison as well as ways to distinguish venomous and nonvenomous snakes.
    • In Arkansas there are 36 kinds of snakes, and only six are venomous. There are no poisonous snakes in Arkansas because poison must be ingested. Venom must be injected. Venom works within the bloodstream, while poison works in the digestive system.
    • Should we bother snakes? Probably not. However, two easy clues can help distinguish venomous from nonvenomous snakes. First, the shape of the head is an easy sign. Snakes whose heads are diamond-shaped are venomous, and those with thumb-shaped heads are generally nonvenomous. Another sign is the shape of the pupil. Nonvenomous snakes have circular pupils, while venomous snakes have slitted pupils, like cat’s eyes. One important exception to these rules is the Texas coral snake. Though highly venomous, it has both circular pupils and a thumb-shaped head.
  4. Ask students to brainstorm ways snakes are beneficial to their ecosystems.
  5. Presentation of the animals is a big part of this program. It can be done throughout the discussion as a visual aid, and if the group is small enough and time allows, participants may touch the animals. 
  6. Discuss the habitat requirements for each of the snakes as they are shown.
  7. Answer any questions.

 

Review:

  • How are snakes helpful to their ecosystems?
  • What characteristics distinguish a venomous snake from a nonvenomous one? Are these methods always dependable?
  • What is a Jacobson’s organ?

Glossary:

Cold-blooded – (ectothermic) – relating to an organism that regulates its body temperature by exchanging heat with its surroundings

 

Jacobson’s Organ – either of a pair of blind, tubular, olfactory sacs in the roof of the mouth, no longer functional in humans but well-developed in many animals, especially reptiles

 

Omnivorous – eating both animal and plant foods indiscriminately

 

Oviparous – birds, fish, reptiles and insects that reproduce by eggs that develop and hatch outside the mother’s body

 

Ovoviviparous – insects, fish and reptiles that reproduce by eggs hatched within the female body (or, in the case of the sea horse, inside the male), so that the young are born alive but without placental attachment

 

Scale – one of the thin, flat, horny plates that cover certain animals such as snakes, lizards and pangolins; or one of the hard, bony plates covering certain other animals such as fishes

 

Venomous – able to inflict a poisoned bite, sting or wound