Images courtesy of Dr. Stephen Secor and Dr. Scott White

Photos courtesy of Dr. Stephen Secor and Dr. Scott White

GRADE LEVEL: 9-12

TIME ALLOTMENT: Two or three 45-minute class periods

OVERVIEW: Using segments from the PBS series Nature episode, Invasion of the Giant Pythons, students will explore pythons and their impact on other species. In the Introductory Activity, students will learn about python digestion and unscramble photos illustrating a python’s digestion of prey. In the Learning Activity, students will learn how pythons have migrated to new environments and the dangers they pose to other species.  Students will learn how invasive species, such as pythons, can threaten native species. In the Culminating Activity, students will learn about the Key Largo woodrat and ways scientists are trying to protect the species from pythons. Students will then explore a native species in their own region and create a presentation about the species, how it is being threatened, and efforts to protect it.

SUBJECT MATTER: Science

LEARNING OBJECTIVES:

Students will be able to:

• Explain where pythons live and how they have moved from one environment to another.
• List python prey and discuss the process by which pythons capture and digest food.
• Describe dangers pythons pose to native species.
• Discuss efforts to rescue the Key Largo woodrat and the reasons why scientists are launching these efforts.
• Discuss one endangered or threatened local species and efforts being taken to help that species.

STANDARDS:

National Science Education Standards

Grades 9-12:

Content Standard C: Life Science
Fundamental concepts and principles that underlie this standard include:

• The Interdependence of Organisms
  • Organisms both cooperate and compete in ecosystems. The interrelationships and interdependencies of these organisms may generate ecosystems that are stable for hundreds or thousands of years.
  • Living organisms have the capacity to produce populations of infinite size, but environments and resources are finite. This fundamental tension has profound effects on the interactions between organisms.
  • Human beings live within the world’s ecosystems. Increasingly, humans modify ecosystems as a result of population growth, technology, and consumption. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening current global stability, and if not addressed, ecosystems will be irreversibly affected.

MEDIA COMPONENTS

Invasion of the Giant Pythons, selected segments

Clip 1: Dinner Time

An overview of how a python captures and digests its prey.

Clip 2: It’s Raining Pythons

A close look at how pythons have entered new environments

Clip 3: Beware: Pythons

A description of the dangers that pythons pose to other species.

Clip 4: Saving the Rats

A look at efforts to protect the Key Largo woodrat from pythons.

Access the streaming and downloadable video segments for this lesson at the Video Segments Page.

Websites

Invasion of the Giant Pythons/ Photos:

These pages on the Nature website illustrate the process by which a python digests its prey. These images can be used in the Introductory Activity.

• Python digesting an alligator

• Python digesting a rat

US Fish and Wildlife Endangered Species Program

This website includes a variety of information about endangered species. The “Species Search” page, used in the Culminating Activity, features a US map where visitors can locate endangered plant and animal species throughout the country.

Optional (for research in Culminating Activity):

• The Comprehensive Everglades Restoration Plan

This website includes a variety of information about the Everglades, including facts about plants and animals:

• California Department of Fish and Game/ Invasive Species Program

This website contains information about invasive species in California and efforts being taken to reduce their negative effects on native species and environments.

• South Florida Natural Resources Center/ Everglades National Park: Natural Resources Management/ Burmese Pythons

This fact sheet provides detailed information about Burmese pythons and efforts underway to monitor and control the python population.

MATERIALS

For the class:

• Computers with internet access
• Computer, projection screen and speakers (for class viewing of online/downloaded video segments)
• One copy of the “Python Digestion Game” answer key (download here)

For each pair of students

• 1 copy of the “Python Digestion Game” (download here)

PREP FOR TEACHERS

Prior to teaching this lesson, you will need to:

Preview all of the video segments and websites used in the lesson.

Download the video clips used in the lesson to your classroom computer(s) or prepare to watch them using your classroom’s Internet connection.

Bookmark any websites that you plan to use in the lesson on each computer in your classroom. Using a social bookmarking tool such as del.icio.us or diigo (or an online bookmarking utility such as portaportal) will allow you to organize all the links in a central location.

Print out one copy of the “Python Digestion Game” for each pair of students. If desired, cut the cards along the dotted lines prior to the class and paper clip each set of 6 cards together. If you do not pre-cut the cards, provide students with scissors to cut out the cards themselves.

Print out one copy of the “Python Digestion Game” answer key.

NEXT: Proceed to Lesson Activities

Excerpts from the NATURE episode, “The Python Problem”

Dinner Time
(View full post to see video)
It’s Raining Pythons
(View full post to see video)
Beware: Pythons
(View full post to see video)
Saving the Rats
(View full post to see video)

Downloadable QuickTime versions of the video segments:
(Note: To download a video, right click on the video title and click “Save Link As…’ or “Save Target As…”. On a Mac, press the CTRL key and simultaneously click the mouse, then save the link.)

Video Clips
1. Dinner Time
An overview of how a python captures and digests its prey.

2. It’s Raining Pythons
A close look at how pythons have entered new environments.

3. Beware: Pythons
A description of the dangers that pythons pose to other species.

4. Saving the Rats
A look at efforts to protect the Key Largo wood rat from pythons.

Guereza Colobus (Colobus guereza)

• Type: Mammal
• Family: Cercopithecidae
• Habitat: Deciduous and evergreen forests
• Location: Across central Africa
• Diet: Leaves and fruit
• Average lifespan in the wild: 20 years
• Size: Head and body 20.5-27.5 in (52.1-69.9 cm); tail 20.5-39.4 in (52.1-100 cm) 
• Weight: 17.2-20.3 lbs (7.8-9.2 kg) for females; 20.5-29.8 lbs (9.3-13.5 kg) for males

Also known as the eastern black-and-white colobus, or the white-mantled colobus, guereza monkeys have a glossy black coat with beautiful white markings. A mantle of long white hairs adorns their back in a U-shape from their shoulders to the base of their tail. Guerezas have a hairless gray face that is also surrounded by white. Their long tail can be either white or yellowish in color, with a large tuft of white fur at the end. This distinctly marked tail is as long as their head and body combined.

Guerezas have a specialized stomach with two different regions, similar to a cow’s stomach, which helps them digest plant cell walls and fibers from their leafy diet. The upper region of the stomach also contains strains of anaerobic bacteria that aid in digestion. This complex stomach allows guerezas and other colobus monkey species to feed on large quantities of leaves. They also eat fruit. Guerezas live in various habitats across equatorial Africa and as a result their diet can be diverse. Their tough stomachs allow them to digest this variety of food.

Guerezas live in small cohesive groups of 8 to 15 individuals. They spend half their day traveling and feeding. Individual guerezas take turns leading the group to different feeding sites, using quadrupedal motion to travel through the trees. Their hands and feet are adapted especially well for this kind of motion through the forest, grasping and walking on tree limbs. Guerezas also run through tree tops, bounding up and galloping across branches, though they usually make only short leaps across horizontal distances.

Guerezas spend the other half of their day at rest. Between feedings, the group takes breaks to relax and groom each other, and after traveling and feeding during the day, a guereza group will congregate each night before sunset in several adjacent sleeping trees. Most groups consist of one male, several adult females, adolescents, and young. Guereza groups often live close to each other or in overlapping territories, though each group is very territorial. At dawn and dusk, males will “roar” as a way of signaling their territory to other groups.

Did you know: The guereza’s genus name colobus comes from the Greek kolobos, meaning “curtailed” or “mutilated,” appropriate because the animal has only four digits on each hand. Its lack of a thumb may be an adaptation to allow for rapid movement through trees.

Photo by Yoky, Creative Commons license.