The Craighead Twins (Series: People Worth Remembering) • (4-9-2023) Tidbits of Coachella Valley

• Grizzly bears once roamed across the entire U.S., but over the millennia they have gradually been eliminated from 98% of their once-free ranges. There was once an estimated 100,000 such bears inhabiting the lower 48 states, while only about 1,000 remain. Yellowstone National Park holds one of the densest populations of grizzlies.

• Because bears are such a popular attractions for tourists, concessionaires in Yellowstone once drew them in to populated areas by baiting them with garbage at locations near lodges. Handfeeding bears along the roadside also became popular as photo ops for visitors. Between 1931 and 1941, a yearly average of 59 tourists were injured in these situations by bears, some seriously.

Yellowstone Park visitors, up close to grizzly bears.

• Park officials knew they needed to get things under control. In 1959, National Geographic hired two naturalists to study the grizzlies of Yellowstone and offer recommendations. John and Frank Craighead were twins with a long history in biological sciences.

The Craigheads fit a sedated grizzly bear with a radio collar, to track its movements and habits.

• The Craigheads pioneered the use of radio telemetry, improving radio collars so much that they vastly increased knowledge of grizzly movement and behavior. They found that 90% of grizzlies in Yellowstone wandered outside of the park. Of those, 45% were killed by landowners.

• Although grizzlies normally live up to 30 years, the average Yellowstone grizzly died by age six, which was problematic since females don’t mate until they turn five. Only one of the grizzlies died of old age. Females mate once every three years, giving birth to between one and three cubs, and 40% of bear cubs die in their first year of life. Only the musk ox has a slower reproduction rate.

• They discovered that a male grizzly will roam a territory equal in size to the state of Rhode Island; that females will babysit and sometimes adopt cubs that don’t belong to them; that males will kill a cub that isn’t theirs. They discovered that bears build a new den every year and never re-use any bear’s old den.

• What was supposed to be a two-year study lasted 12 years. The Craighead brothers and their assistants performed 9,000 person-days of research, hiked over 162,000 miles, and captured, marked, and studied 256 grizzlies.

The Craighead twins observing grizzlies from a distance, in Yellowstone Park.

• Then, in 1967, two young women were killed on the same night by grizzlies in nearby Glacier National Park. As a result, officials in Yellowstone wanted to immediately close all the dumps where bears fed.

A grizzly waits for a load of trash to be unloaded at Yellowstone's dump.

• The Craigheads objected to this plan. The bears depended on the dumps as one of their main sources of food; closing them all at once would have catastrophic results, forcing the bears into campgrounds in search of food, sending them after livestock, increasing interactions with humans, and leading to starvation among bears unable to find another food source on short notice. They advocated for closing the dumps gradually, allowing the bears enough time to readjust their feeding habits.

• Yellowstone officials disagreed. For their efforts, the Craigheads were banned from the park. Their laboratory was bulldozed. And all of their predictions came true: the grizzly population of Yellowstone dropped catastrophically, until grizzlies were ultimately placed on the Endangered Species list in 1975. Frank and John Craighead wrote a book about their discoveries, “The Grizzlies of Yellowstone” and went on to enjoy long careers as naturalists and researchers.

• By the time Frank died in 2001 and John died at the age of 100 in 2016, agencies throughout the Yellowstone region had adopted all of the recommendations they had advocated. This included having all agencies work together; eliminating sport hunting and imposing stiff penalties for poaching; instituting public education; placing strict rules for food storage on public lands, and canceling livestock allotments near park boundaries.

Yellowstone Parks grizzly population is rebounding.

• The grizzly population soon doubled, all thanks to the tireless research accomplished by the Craighead twins. □