A Bear’s Menu
OverviewWorking in small groups, students examine the feeding habits of bears and draw pictures to show what bears do in spring, summer, fall, and winter. Students use a small pattern of a grizzly bear and increase its scale to construct a full-size silhouette in order to appreciate the bear’s size.
Objective(s)The student will:
- Describe the seasonal cycle of a bear's life by examining its eating habits.
- Recognize the shape and size of an adult grizzly bear and compare it to his/her own body size.
BackgroundYellowstone provides habitat for both black and grizzly bears. Although they are different species and each has unique physical and behavioral characteristics, they share similar diet requirements. Their feeding habits determine the locations bears inhabit during the year as food availability changes with the seasons.
Grizzly bears were listed as a “threatened” species in 1975 under the Endangered Species Act. Because of the animal’s great size and need for large unpopulated, tracts of land, Yellowstone has identified specific areas of the park as essential bear habitat, where human use is limited and bears pursue natural behavioral patterns. This management of the land is essential for the protection and recovery of this threatened species. The status of grizzly bears in regards to the Endangered Species Act continues to change as scientists further study the specific requirements of these bears for survival.
MaterialsYellowstone Bears handout, Bear Food Chart handout, Bear Characteristics handout, large circular pieces of paper, markers, crayons, pencils, Grizzly Bear Pattern handout, rulers, drawing paper (total of 8 pieces, each 24" x 36")
For Activity #1 – Seasons of the Bear
The teacher will:
- Divide students into small groups and distribute the Yellowstone Bears handout. Allow time for students to read it aloud in their small groups and complete the charts.
- Discuss the differences in physical characteristics and behavior between black bears and the grizzly bears. Compare the diets of black bears and grizzly bears.
- Distribute the Bear Food Chart to small groups. Discuss how to read the chart and be sure all students understand how to interpret its information. Pass out large circular sheets of paper. Instruct students to divide the circles into fourths and label them spring, summer, fall, and winter. Have students draw bears during each of the seasons, illustrating what the bears eat at that time of year. Students may wish to use the Bear Characteristics handout for accuracy in their drawings.
- Collect and display drawings. Discuss the bears' yearly feeding patterns. Why is this called a cycle?
- Ask students where bears are at this time of year.
- Read aloud and discuss the following Yellowstone National Park press release dated October 3, 1994.
This year has been a very poor food year for bears in the Yellowstone Ecosystem. Because of the mild winter, very few winter-killed ungulate carcasses were available for bears to scavenge on this spring. Winter-killed carcasses are an important high-quality food source for bears in the early spring before most vegetal foods are available. Cutthroat trout spawning numbers in Yellowstone Lake tributaries were lower than average this summer; spawning cutthroat trout, available to bears during the spring and early summer, rank as one of the highest sources of energy for bears in the Yellowstone Ecosystem. This summer was also drier than average, and as a result most vegetation dried out early. Army cutworm moths, an important late summer food, appeared less abundant than in recent years. In addition, whitebark pine trees within the Yellowstone Ecosystem produced almost no cones this year. Whitebark pine seeds are especially important because of their high fat content and their potential abundance as a prehibernation food source. The combination of all these factors has left bears with very few foraging opportunities, especially during the late summer/fall seasons when bears begin searching intensively for high-energy foods prior to denning.As a result of these factors, areas outside of Yellowstone National Park have been experiencing a much higher than average number of bear-human conflict situations at private homes, lodges, and campgrounds. In an effort to reduce bear-human conflicts and promote the conservation of grizzly bears in the Yellowstone Ecosystem, Yellowstone National Park has accepted grizzly bears involved in bear-human conflicts from the states of Wyoming and Montana for translocation into the park. This year eleven different grizzly bears were translocated twelve times from areas outside of the park to areas within the park. The park accepted these bears for relocation into the park to allow personnel from the Wyoming Game and Fish Department and the Montana Department of Fish, Wildlife, and Parks to work with private landowners to bear-proof facilities so that bears would not be attracted to private landowners' property.Yellowstone National Park officials remind all people living in Bear County that garbage and other attractants should be kept secured so as not to attract these large and potentially dangerous animals into residential areas.
7. Pose the question: Could this happen again? Some biologists warn that bears' traditional food sources are declining all across the Yellowstone region. Bison herds are smaller, thereby reducing the amount of winter-killed carcasses available, cutthroat trout are being eaten by lake trout in Yellowstone Lake, and a fungus is killing the whitebark pine trees that supply the nuts that many bears fatten up on in the fall. What do you think could happen if these trends continue? What can be done, if anything, to protect these important food sources?
Suggested Procedure for Activity 2—Graph a Grizzly
The teacher will:
- Divide the students into eight groups. Explain that the class will be making a life-size cutout of a grizzly bear. Distribute the grizzly pattern to each group and assign one piece to each group. Also distribute a piece of drawing paper to each group. Have students create a grid of 4" squares on their drawing paper (at least five squares by four squares) in pencil.
- Explain to students that they will be increasing the size of the drawing on the pattern four times. Discuss ratio if this is part of your mathematics curriculum. Ask students to transfer each pattern piece, enlarging the scale of the lines drawn on the pattern.
- Have students cut out their enlarged pieces, fit them together, and tape them.
- Display the grizzly bear low on the wall where students can get down on all fours and compare their size to that of the grizzly bear.
- Have students review the information on the Yellowstone Bears: Grizzly Bears handout they completed in the previous activity.
- Discuss differences between grizzly bears and students, especially size. Are there any similarities in diet? Discuss importance of habitat for an animal as large as a grizzly bear. Discuss Yellowstone's role in protecting grizzly bears.
Park ConnectionsStudents learn about grizzly and black bears both of which live in Yellowstone National Park.
ExtensionsLook up the current status of grizzly bears in regards to the Endangered Species Act. Discuss what factors were used to determine the current status of grizzly bears.
Additional ResourcesThe Bears of Yellowstone Electronic Field Trip. This field trip is currently unavailable.
Dolson, Sylvia (2009). Bear-ology: Fascinating bear facts, tales, & trivia. Masonville, CO: PixyJack Press, LLC.
Shapira, Amy, Douglas H.Chadwick (2011). Growing Up Grizzly: The true story of Baylee and her cubs. Helena, MT: Falcon Guide.
Wondrak Biel, Alice (2006). Do (Not) Feed the Bars: The fitful history of wildlife and tourists in Yellowstone. Lawrence, KS: University Press of Kansas.