But who is the grolar? Also called “pizzly”, this ursid is the result of a cross between a grizzly bear and a polar bear. Having become a subject of study for scientists, this hybrid animal fascinates as much as it worries, symbolizing the profound environmental changes underway in the Arctic.
Recent and increasing hybridization
The grolar was first identified in the 2000s, when a hunter in Canada killed a strange-looking bear. And for good reason: DNA analyzes subsequently revealed that it was a hybrid. Since then, several cases have been confirmed, particularly in regions of the Canadian Arctic archipelago. This hybridization remains rare, but its frequency increases as polar bears, driven by melting ice, approach grizzly bear territories.
In Alaska, in the heart of the bear kingdom
A 2017 report published in Biology Letters highlighted that grizzly bears now venture up to 72 degrees north latitude, territory they previously avoided. This expansion, coupled with the reduction of polar bear habitat, encourages interbreeding.
A hybrid biology
The grolar has impressive physical characteristics that make it extremely effective. Its size can reach 2.4 meters in length when it stands on its hind legs, with a weight varying from 300 to 400 kg. Its skull, intermediate between that of a grizzly bear and a polar bear, combines robustness and length, while its legs, long and powerful, make it an excellent swimmer and a formidable predator on land.
These characteristics allow it to be both an excellent swimmer, capable of covering up to 50 kilometers without pause, and an opportunistic predator. It combines the instincts of the grizzly bear – hunting caribou or fishing for salmon – with the maritime hunting skills of the polar bear, such as catching seals on the ice.
Finally, its coat, generally cream or light brown in color, allows it to adapt to a diversity of environments – and to colonize them.
An ecological and human danger
These hybrids pose complex conservation questions, posing a threat to local ecosystems as apex predators. Scientists fear that the grolar will gradually replace the polar bear in certain areas. A study published in 2016 in Global Change Biology estimated that the polar bear could lose up to 30% of its population by 2050, partly due to hybridization.
Grolars also pose dangers to human populations. Although they remain rare, their impressive physical abilities make them formidable opponents if encountered. In 2019, a hybrid destroyed several shelters in a remote area of Alaska before attacking two people, who were injured, before the animal was put down. These incidents, although infrequent, show the extent to which these hybrids, little intimidated by humans, can be dangerous in areas where human activity crosses their territory.
Fertile reproduction and delicate management
Unlike many hybrids, grolars are fertile. They can reproduce with each other or with one of the parental species, creating a new hybrid generation. A 2021 study led by the University of Alaska found that second- and third-generation grolars already exist, with increased adaptations to changing environments.
However, this fertility complicates their management. Their hybridization places grolars in a gray area in terms of legal status: protected like polar bears, or not recognized as a distinct species? This ambiguity makes their management difficult, particularly in the event of conflict with humans. Local authorities, particularly in Canada and Alaska, are struggling to find a consensus between preservation and control.
Where can you find grolars?
Grolars are not evenly distributed across the Arctic. Confirmed sightings are mainly concentrated in northern regions of Canada, such as Banks Island or Victoria Island. These areas, where grizzly bear and polar bear habitats overlap the most, are hot spots for hybrids.
In Alaska, more recent reports suggest that the grolar could expand its territory, in particular due to the advance of grizzly bears northward due to global warming. Scientists believe that reinforced monitoring in these regions is necessary to better understand the dispersal of hybrids and anticipate their impact on local fauna.
