Wildlife tracking technology that adheres to fur delivers promising results from trials on wild polar bears

Studying polar bears just became a lot easier with new "burr on fur" trackers which confirmed scientists' belief that subadult and adult males spend most of their time on land lazing around, conserving energy until the ice returns.

A multi-institutional research team led by York University and including the University of Alberta, Environment and Climate Change Canada, Manitoba Sustainable Development, Ontario Ministry of Natural Resources and Forestry, and Polar Bears International, used three different "burr on fur" prototypes to study their effectiveness.

The paper, "Telemetry without collars: performance of fur- and ear-mounted satellite tags for evaluating the movement and behavior of polar bears," published in the journal Animal Biotelemetry, details the first peer-reviewed examination of these new tracking devices that adhere to the fur of polar bears.

Studying polar bears is a difficult feat with current radio collars only suitable to be used on female bears leaving out a swath of the population, but new technology is providing researchers with a new tool which has confirmed the behavior of adult male polar bears while on land waiting for the ice to form again.

Efforts to develop less-invasive tracking options and tools that could work on polar bears of both sexes and nearly all ages have been ongoing for years with varying success. Collars have been and remain the primary means of studying polar bear movements. More recently, ear tag transmitters have been used as a lighter-weight alternative.

While both technologies serve an important role in helping study and conserve polar bears, researchers continually strive to develop methods that are both minimally invasive and provide quality data.

This led to a new tracking initiative known as "Burr on Fur," which began as a challenge from Polar Bears International to 3M scientists, the global science and manufacturing company behind Post-It notes, to create a temporary, simple method for affixing small tracking units to polar bear fur. Three "Burr on Fur" prototypes were recently tested on wild polar bears along the coast of Hudson Bay, Canada, alongside traditional ear tag transmitters.

The shortcomings with traditional tracking methods

The ear tag and "Burr on Fur" devices fill an important niche for scientists and wildlife managers. The new tags allow researchers to follow the movements of adult male and subadult polar bears, two groups that can't be studied using traditional satellite collars. Adult males can't wear collars because they slip off their cone-shaped necks and heads, and subadult bears grow too rapidly for safe collar use.

Traditional ear tags are an alternative to collars. However, they currently require recapture to remove and, although rare, can pose a risk of injury to the ear. The new Burr on Fur tags are designed to be temporary, minimally invasive, and can be applied to both sexes and nearly all ages of polar bears.

"Successfully attaching telemetry tags to polar bear fur has never been done before, and we're excited to share the results of this innovative work," said Tyler Ross, lead author of the paper and researcher at York University. "The fur tags showed great promise, and give researchers the ability to study the behaviors and movements of polar bears that we have very little data on, like subadult and adult male bears."

A total of 58 wild bears were tagged using ear tags and three distinct fur tag designs to compare both the duration of time the tags remained active while attached to the bears and the accuracy of the trackers. Applied alongside a traditional ear tag, which relied on an Argos Transmitter, the three fur tags were:

• The Pentagon Tag: this five-sided device included five holes punched into its corners, allowing tufts of fur to be pulled through. It utilized an Argos Eartag Satellite Transmitter.
• The SeaTrkr Tag: an oval-shaped tag that had 10 holes punched to allow 10 fur-tuft attachments. This design used an Iridium-linked Telonics GPS SeaTrkr-4370 transmitter.
• The Tribrush Tag: a triangle tag outfitted with tubes along its borders, through which pipe brushes ensnared the fur, twisting it inside the tubes. This tag used the same Argos transmitter as the Pentagon tags.