Technology helps illuminate Yellowstone bears
It takes a hike over high ridges and numerous toppled lodgepole pine trees to find the small pool of fresh water in Yellowstone National Park.
This is not some out-of-the-way hot springs that adventurous tourists seek out to soak in. Instead, the well-worn trails marked by tracks leading to the site attest to its use as a “bear bathtub.”
The first of these pools was discovered more than a decade ago by Yellowstone bear researchers as they searched for a tracking collar that had fallen off one of the bears they were studying, according to an article in the recently released issue of the journal Yellowstone Science. The signal sent by the collar led them to the small pond at the end of a narrow gully surrounded by forested hills, according to the article’s lead author, Kerry Gunther, Yellowstone’s bear manager.
The radio transmitter identified the soft muck on the bottom of the pool as the resting place for the collar. Using a trekking pole, the collar was extracted and the important information it contained was downloaded. The researchers also took note of the pond.
It was described as a “bathtub-size pool of water, 2-3 feet deep and approximately 3-4 feet wide by 8-10 feet long. Four well-worn game trails, all with numerous bear tracks, led in to and out of the pool of water.”
Years later, the idea of placing a remote camera trap at the site was proposed by National Geographic magazine photographers as they sought to create unusual photos for an upcoming issue devoted entirely to Yellowstone National Park as the nation celebrates the 100th anniversary of the creation of the National Park Service.
The cameras snapped a photo of one grizzly, its fur soaked, sitting at the end of the pool like a tourist relaxing in a pool at a four-star resort. Another photo shows one bear easing into the water as two others watch from behind, likely a sow and two yearling cubs.
“Photo and video documentation indicated (the pool) was used by multiple individuals of both black and grizzly bears,” the article stated. “Bears came to the pool, soaked, bathed and cooled off. Females brought their cubs to play at the pool. Even adult bears were observed playing with sticks pulled up from the bottom of the pool. Interestingly, bears also scent-marked along the edge of the pool, rubbing their necks and cheeks on the ground and lush grasses surrounding the pool. We hope to learn more about the scent-marking behavior observed at the pool. Regardless, it appears that bears enjoy a nice cold soak on a hot summer’s day as much as humans do.”
The article also noted that since that first collar was recovered from a bear bathtub, several others have been retrieved from similar remote, small ponds.
“The park likely has many such places visited by bears to bathe, soak, play and scent mark,” Gunther wrote. “The bear bathtub is just one of the many special places in Yellowstone National Park that grizzly bears have helped us discover.”
The use of camera traps points to the increasing role that specialized technology can play in aiding scientific research of typically shy animals like grizzly bears.
In a similar 2014 experiment cataloged in the journal, researchers fitted two male grizzly bears and one male black bear with collar-mounted cameras that captured 20 seconds of video every 20 minutes. The videos are meant to help “determine the animal’s activities and behavior at specific times and locations,” according to the article’s lead author, Nathaniel Bowersock, a Yellowstone wildlife biological technician.
The video from one of the grizzly bear’s cameras is still being processed and studied, but the 2,600 clips from the other two bears have revealed some interesting details that could be compiled into a new YouTube hit.
The black bear was a wanderer, ambling from near Mammoth Hot Springs, Wyo., where he was captured, to the West Yellowstone area. While scavenging on an elk carcass, the bruin killed and fed on “what appeared to be an old female black bear, after she approached too closely when he was feeding on the elk carcass.”
Although capturing that video may seem pretty amazing, what struck Bowersock as unusual was the speed with which the black bear “moved while foraging on small plants and mushrooms,” a pace similar to the bear’s usual traveling speed. The information gives new meaning to the phrase “a moveable feast.”
Although the black bear was most active during the day, the collared grizzly bear slept most of the day and foraged at night. Consequently, a lot of the video shows the grizzly sleeping in day beds. (It’s believed black bears forage in the day to avoid running into grizzlies at night.)
“One of the more interesting video segments from (the grizzly bear’s) collar was the distant lights of the town of Gardiner, Montana, while he fed in apple orchards at night along the Yellowstone River within the Gardiner Basin,” Bowersock wrote.
Although the study was small, Bowersock wrote that the technology has the potential “to increase our knowledge of bear activities, movements, food habits and interactions with other bears.”
In his introduction to the articles, Gunther wrote: “When I first began working in Yellowstone National Park in the early 1980s, it was fairly uncommon to see a bear, grizzly or black. If you saw a dozen bears in a summer, you considered it a good bear year. Today, you can easily see a dozen bears in one morning or even on one bison carcass.”