SHOW 303: The Channel Island Fox
A small fox on Santa Catalina Island off the coast of California provides a living clue to Native American people who lived and traded on these islands about 2,000 years ago. Evidence found in island graves shows that some of the people who lived here worshipped the fox. As a tribute to that tradition, one of the last descendants of the island peoples honors the fox with a ritual dance that links past and present. In an ongoing project, archaeologists work together to unearth a picture of the past, while biologists join forces to preserve remaining foxes from encroaching civilization.
Activity: Scientific Sampling
Notes & Discussion
Across the Curriculum
Report From the Field: Dave Garcelon, Field Biologist, Institute of Wildlife Studies
ACTIVITY: SCIENTIFIC SAMPLING
As you've seen on FRONTIERS, archaeologists and other scientists use different clues to piece together a picture of the past. Biologists like Dave Garcelon and Gary Roemer, who study the Channel Island fox, rely on both simple (notebook and pen) and complex (DNA analysis) techniques to understand more about threatened and endangered species. These activities allow you to conduct three types of scientific research.
A. A MODEL GEOLOGY
- remoldable clay
- foil pie pans
- food coloring
- map of ocean floor
Because of their geological formation (the oceanic volcanic peaks that form the archipelago), the Galapagos Islands are famous for their unique diversity of life. The Channel Islands, too, experienced a similar diversification of plant and animal species. In this activity, you will build a model to compare the geography and geology of both island groups.
Consult a topographic map of the ocean floor and then, using remoldable clay and two tin foil pans, mold the Galapagos Islands onto the bottom of one pan and the Channel Islands onto the bottom of the second pan. (Make sure the clay covers the entire bottom of the foil pans.) In each model, include part of the coastline of the continent associated with the group of islands. Create an "ocean" out of food coloring and water. (This is particularly spectacular if you create the models in clear plastic storage boxes, and use blue-green liquid and terra cotta-colored clay.) When you pour the water off, observe how the islands are part of a continuous landform that connects to the mainland.
B. FURRY COMPARISONS
- various lengths and types of fibers (yarn, wool, synthetics, orlon, etc.)
- spray mister
- talcum powder, flour or cornstarch
The Chumash people on the northern Channel Islands probably traded fox pelts. In this activity, you will compare the characteristics of various types of fibers in an attempt to find out which is more desirable. (Note: wool fiber most closely approximates fox fur.)
- Cut 10 strands of the same material into 10 cm lengths. Tie together with string at one end.
- Cut 20 strands of the same material into 10 cm lengths (this bunch represents thicker fur).
- Cut 10 strands of the same material into 20 cm lengths (longer fur).
- Cut 20 strands of the same material into 20 cm lengths (longer, denser fur).
- Spray mist each fiber "mane" with water.
- Observe how the fiber sheds water.
- Experiment by combining materials for better water shedding.
- What repels water better -- thicker, shorter fur or longer, denser fur? Are combinations of materials better at repelling water?
- Hypothesize about what would protect the body more effectively from the wind -- thicker or longer fur?
You can set up a systematic method for testing the fur swatches with a square of cardboard to which you attach your sets of knotted fibers, one at a time. You can vary the numbers and lengths of the fibers. Before attaching the fibers, dust the cardboard lightly with talcum power, flour or cornstarch. Test the thinnest samples first with the spray mist. Record how well the fiber sample protects the dusted board. Don't forget to redust after each trial! You can use math symbols or design your own ratings. For example: more than adequate > A; adequate A; less than adequate < A.
C. OBSERVING ANIMALS IN THE FIELD
You can do the work of a naturalist by using a pencil and a notebook. You might wish to observe one backyard animal (such as a chipmunk, squirrel or bird) or use your own or a friend's pet. Observe the animal over a selected period of time, perhaps the same time for a series of days, noting eating, sleeping, playing and other activities. Keep careful notes. Do you observe patterns? You might want to try this experiment in two different seasons of the year; does the animal behave differently? If it's a pet, when does it shed its fur? This exercise will require patience!
- These three activities can be performed individually or in small groups, "A Model Geology" demonstrates the continuity between an island and the continental shelf; the model should be created as a continuous clay mass. The activity can also be used to launch a comparative study of the geology and geography of the Galapagos and Channel Islands. (Both groups of islands are noted for their striking diversity of flora and fauna that evolved over the millennia.) In "Furry Comparisons," students demonstrate the water-repelling characteristics of various fibers. "Observing Animals in the Field" enables students to try some of the field skills used by naturalists.
NOTES & DISCUSSION
- About 2,000 years ago, the Chumash and Gabrielino tribal groups were among the Native Americans who called the Channel Islands home. Now virtually extinct, these early inhabitants left behind a few clues to their culture in the form of artifacts, which archaeologists interpret to form a portrait of these early Americans.
- Archaeologists on Santa Catalina have been digging in a midden, or garbage dump, for clues that will tell them more about the Gabrielino people who once inhabited the site, What else do the researchers learn from their finds on the island? By at least one estimate, every American throws out 3 1/2 pounds of trash every day. What will today's landfills tell future archaeologists about our culture?
- The scientific name for the Channel Island fox is Urocyon littoralis -- similar in appearance but smaller than the mainland gray fox. Using DNA analysis, biologists have determined that all the subspecies of foxes on the islands probably descended from a mainland fox that somehow made its way to one of the islands thousands of years ago when ocean levels were lower and the coast much closer. Archaeologists surmise that the Chumash and Gabrielino people traded back and forth between islands, probably bringing the fox either for trade or to give away as a pet.
ACROSS THE CURRICULUM
- Geography: Locate the Channel Islands, a chain that extends along the Southern California coast from Point Conception to San Diego. Identify the individual islands.
- History: What cultures were thriving in other parts of the world at the time that the Chumash people are believed to have inhabited the islands? What happened to the Native American cultures after the arrival of the Europeans? (in the 18th and 19th centuries, life on the Channel Islands was permanently disrupted when the Native Americans were removed to missions)
- Geology: Describe the formation of the islands. (they're exposed tops of a mountain range that pushed up from the ocean floor about three million years ago)
- Social studies: Why do you think the native cultures venerated the fox? What might life have been like on the Channel Islands during the centuries before European contact? (consider climate, food and other resources, social organization)
REPORT FROM THE FIELD: DAVE GARCELON, FIELD BIOLOGIST, INSTITUTE OF WILDLIFE STUDIES
Wildlife biologists like Dave Garcelon play an important role in getting a species recognized as endangered or threatened by state or federal governments. "Biologists in the field are doing the groundwork by trying to discover the exact status of the species," says Garcelon. "A threatened species is considered likely to become endangered within the foreseeable future, while an endangered species is actually in danger of extinction."
What criteria indicate that the Channel Island foxes might be endangered? "If I find by the daily trapping that the number of foxes is declining, it would be the first sign to alarm me," Garcelon replies. Other potential dangers include disease, even from a domestic dog (the foxes have not developed immunities), and habitat destruction caused by the large numbers of sheep and goats that have no natural predators on the islands.
When he was in grammar school, Garcelon realized he wanted to work with natural resources. At first he envisioned being a park ranger, later a mammologist. As he learned more, he decided he wanted to study a variety of species and their habitats, so he pursued wildlife biology. About five years ago while on another project, Garcelon began working with the Channel Island foxes. He was immediately fascinated and hopes to continue studying them for a long time. "When you're trying to learn about a species that has a five- to seven-year life span, it takes a long time to find out all the details," he observes. "It takes years to learn how an animal interacts with the environment and what has to be done to conserve the species.
Garcelon considers wildlife work a very rewarding career. "You feel satisfied that you've done something good for the species, and therefore the planet."
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