A brown bear emerges from hibernation and is responsible for the deaths of 38 young reindeer.

Researchers have shown that some bears are more likely to attack than others.

 

According to new research, a "very predatory" brown bear murdered 38 reindeer calves in one month after emerging from hibernation and 18 young moose the next month.

 

A female brown bear, aged 13, was one of 15 that were followed by scientists in northern Sweden so that they could learn more about the bears' ecology and behavior. They discovered that bears shift their territory in the spring in search of newborn reindeer and moose. Certain bears, such as the female who shall remain nameless, killed more calves than others, and this affected the specific territory they occupied.

 

Exactly what makes certain bears more predatory than others? Antonio Uzal Fernandez, a senior lecturer in wildlife conservation at Nottingham Trent University in the United Kingdom and co-author of the study, told Live Science via email that "it must be a combination of different factors," including innate behavior related to personality (for example, some people are more aggressive than others).

 

The study's authors found no evidence that the "very predatory" bears posed a greater risk to humans than they did before.

 

The brown bear (Ursus arctos) has a wider range than any other bear species, with 45 countries reporting its presence spanning North America, Europe, and Asia. This new publication is a part of an ongoing research project examining the lifestyles of brown bears in Norway and Sweden.

 

With the help of GPS collars, the new study follows bears from 2010 to 2012, documenting their prey selection and killings. According to a statement provided by Nottingham Trent University, brown bears in Sweden migrate to high-elevation, rough terrain during the reindeer calving season and then to habitats utilized by calving moose, such as adjacent deciduous forests. This gives them an advantage when hunting young calves.

 

The researchers traced the ranges of various bears and compared their respective kill rates. According to the study, bears were dubbed "high predatory" if they killed more than the average kill rate across all of the bears — 0.4 kills per day — and "low predatory" if they killed at a lower rate than that, according the study. The scientists noticed some differences between where high-and low-predatory bears went. For instance, compared to the open environments preferred by low-predatory bears, high-predatory bears tended to congregate in forests where there were more reindeer.

 

There were 15 bears, 8 of which were classified as "very predatory" due to their habit of killing multiple young mammals throughout the calving season. Bears are less successful when hunting larger adult prey, so they focus on calf prey until July, when the calving period finishes, and they switch to a berry diet until they can go back into hibernation.

 

In explaining individual variance in habitat selection, "our work illustrates the heterogeneity between individual bears' predatory behaviour," Fernandez said. From a managerial standpoint, "differences among individuals are also essential; for example, sheer predator eradication, without targeting specific individuals, may not always lessen conflict." This is because certain bears are naturally more confident and bold than others.

 

The indigenous Sámi people of Sweden practice a form of semidomestication with reindeer herding. When bears threaten reindeer, humans annually resort to killing them. According to the study, the new information could aid in developing forecasts for possible bear-reindeer hotspots, thereby reducing conflicts between the two species. Researchers believe that identifying bear attack hotspots could help livestock owners take precautionary measures to reduce losses, such as greater vigilance in regions where bears are more likely to attack during the calving season.

Reference : https://www.livescience.com/highly-predatory-brown-bear-kills-38-reindeer

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