How many grizzly bears are out there? Where do they rest and roam? How are bear populations and movements changing over time?
The world of wild animals is still in many ways a mystery to us. We seek answers to these questions in order to better conserve grizzlies, but bears aren’t like humans. We can’t just ask them to fill out the 2020 Census with their most recent address and number of household members.
Telemetry— the process of remotely sending information from one location to another via radio waves or satellite technology— offers us a glimpse into the universe of grizzly bears beyond simple field observations.
Using GPS or Very-High Frequency (VHF) collars, researchers glean insights into bear behavior, habitat use, reproduction, mortality, and other data on how these animals move and groove across landscapes.
The Interagency Grizzly Bear Study Team (IGBST)— a coalition of regional agencies including the National Park Service, tribal nations, and Game & Fish departments— began collaring grizzlies in the Greater Yellowstone Ecosystem (GYE) in 1975, when the grizzly was listed on the Endangered Species Act.
Since then, the team has radio-monitored more than 830 bears.
“It varies quite a bit year by year,” said Dan Thompson, Wyoming Game and Fish Large Carnivore Supervisor. “But we’re usually capturing twenty to thirty grizzly bears for monitoring purposes, and those bears will wear a collar for a couple years, and then they drop off.”
The IGBST isn’t trying to capture every grizzly in the GYE. Rather, they seek to maintain a representative demographic sample of grizzlies in the ecosystems— meaning, bears of different ages, sexes and home ranges from which information can be inferred about the larger GYE grizzly bear population.
It’s no small feat to collar a grizzly bear weighing hundreds of pounds. First, wildlife officials must close off the trapping area to the public so that no unbeknownst hikers or curious minds come wandering.
“A lot of people try to check out a grizzly bear trap if it’s on public land,” Thompson said.
Primarily, researchers use box-type traps, which resemble giant tin cans with sliding trap doors. Road kill is placed inside as a lure. They must then continually check the trap, either daily in person or continuously via cameras. When a bear enters the trap, a trigger system shuts the door.
If a bear is successfully captured, it is immobilized via sedation, after which researchers quickly commence data collection.
“It’s amazing the amount of information you can collect having one animal in hand,” said Thompson.
Researchers take biological samples of blood and tissue, which allows them to assess genetics. Through hair and blood analysis, they can look at diet to discover what an animal is eating. They take measurements of body fat and weight.
Finally, the animal is marked so that it can be identified if recaptured in the future, and often (though not always) a collar is placed around its neck. Researchers then stay with the bear until it is fully awake to assure it recovers properly from sedation.
This isn’t like collaring your dog. “They’re not going to be wearing a collar forever. We don’t want that,” said Thompson.
Because grizzly bears are powerful, undomesticated creatures exposed to the elements, a “breakaway link” on the collars typically dissolves within 2 to 3 years, or there may be a remotely released mechanism on the collar.
Not only does this data collection allow scientists and conservationists to holistically understand the health and status of grizzly populations at any given time, it also allows them to answer specific research questions. For example, as whitebark pine trees–the seeds of which have been historically a vital food source for grizzlies–decline due to beetle die-offs, are grizzly bear movements on the landscape changing as they seek different food sources and habitats?
By tracking grizzlies, we are able to better understand how they are impacted by forces such as food source shifts, human presence and climate change.
Trapping and collaring grizzly bears, however, isn’t universally celebrated.
While the science doesn’t point to any long term negative impacts on grizzlies from capture or sedation, the International Association for Bear Research and Management (IBA) notes three possible animal welfare concerns with bear collaring: the stress and risk to bears during capture; the potential for an ill-fitting collars resulting in physical discomfort or harm; and the possibility that collars do not fall off, thereby staying on longer than desired.
Though the IGBST follows strict safety and animal care protocols, in 2019, a seven-year old male grizzly bear was found dead in a trap, likely due to exhaustion and heat. This was considered extremely rare by Wyoming Game and Fish— the first ever of such an incident of mortality.
Others oppose collaring based on its aesthetic impact. “You can’t sell a picture of a bear with a collar as well as you can without,” said Thompson. In part, this may be because a collared bear is seen as tamed or somehow less wild. As Thompson admitted, “Unfortunately it kind of takes some of the mystique away at times.”
There’s also a fear that some hunters intentionally target collared animals as an act of animosity against scientists and wildlife research. Scant evidence exists to prove such malicious intent, but the shooting of the famed Yellowstone alpha “Female 06,” who was collared, unleashed accusations from conservationist and wolf advocates that hunters were doing exactly that.
Even worse, the incident raised speculations that hunters were hacking wolf GPS locations. Again, there wasn’t evidence to prove this, but it does raise another disturbing possibility with tracking–cyberpoaching.
“Animal tracking can reveal animal locations (sometimes in nearly real‐time), and these data can help people locate, disturb, capture, harm, or kill tagged animals,” write Cooke et al. 2017 in their paper, “Troubling issues at the frontier of animal tracking for conservation and management.”
So far, there’s only been one known attempt at such a hack, in India in 2013, when poachers tried to uncover the GPS location of an endangered Bengal tiger. Luckily they were unsuccessful, but Cooke believes there could be more issues like this in the future.
These concerns aside, telemetry has proven an invaluable tool in the management of grizzly bears and other animals across North America, and it’s not one that researchers are readily willing to sacrifice.
“If I never had to put a collar on a bear I’d be fine with that,” said Thompson, “but the information we’ve learned on bears in the last several decades through collaring has led to so much more of an understanding of these animals and their unique role on the landscape.”