Photo 12 Sep 177 notes Bear hair study in Banff proves animal highway crossings work

The crossings in Banff National Park include two wide overpasses covered in vegetation that helps them resemble the surrounding habitat. Underpasses provide the cover cougars and many small mammals need, while the bridges and overpasses let moose and elk traverse in their preferred open-sky habitats. Cameras at each of the passageways have recorded hundreds of thousands of crossings for many different species, including bears, wolves, lynx, deer, elk and moose. A wolverine made the news when a camera captured its walk across an overpass, becoming the first such venture recorded for its species. But cameras couldn’t help scientists collect data about individual crossings. “We could show that there were a lot of crossings, but what did that mean? Was it one bear crossing 100 times or 100 different bears crossing once?” Ament and the researchers at MSU wondered. Answering this question was critical to understanding overall health of the animal communities.
What the researchers discovered was encouraging. Over the three-year study, 15 different grizzly bears and 17 different black bears used the crossings. While those may not seem like huge numbers, they represent a significant portion of the populations. Using estimates of the populations of grizzlies and black bears in Banff, these individuals represented close to 20 percent of the population for both species. Previous research estimates that, for large mammals like bears, about 10 percent of a population needs to cross back and forth to ensure a healthy ecosystem. Comparing samples from year to year and in different locations, the researchers can begin to construct family trees for the bears and observe genetic diversity in offspring.
To collect the hair samples, researchers set up lines of barbed wire by several of the crossings. As bears passed, the barbs would snag a bit of hair. To learn about the bears’ movement once they crossed, the team also set up wires near trees that the bears used as scratching posts. Finally, they doused piles of wood 8.5 miles from the highway with cow blood and fish emulsion, a stomach-turning scent for us but an enticing curiosity for the bears. Again, when the bears came to investigate, barbed wire nearby would help keep track of which bears visited.
Over three years, the team collected more than 10,000 strands of bear hair. In addition to finding out that the passageways helped keep the populations healthy, the researchers learned that grizzlies preferred the wide-open overpasses while black bears primarily used the underpasses. Roughly equal numbers of males and females for both species used the crossings, and the genetic sampling lets biologists know more about the population’s family trees. While the team could have chosen any number of species to monitor, they knew there were enough bears to collect significant data and, since scientists are concerned about their declining populations, the data could be relevant in broader studies.

(Read more at High Country News)

Bear hair study in Banff proves animal highway crossings work

The crossings in Banff National Park include two wide overpasses covered in vegetation that helps them resemble the surrounding habitat. Underpasses provide the cover cougars and many small mammals need, while the bridges and overpasses let moose and elk traverse in their preferred open-sky habitats. Cameras at each of the passageways have recorded hundreds of thousands of crossings for many different species, including bears, wolves, lynx, deer, elk and moose. A wolverine made the news when a camera captured its walk across an overpass, becoming the first such venture recorded for its species. But cameras couldn’t help scientists collect data about individual crossings. “We could show that there were a lot of crossings, but what did that mean? Was it one bear crossing 100 times or 100 different bears crossing once?” Ament and the researchers at MSU wondered. Answering this question was critical to understanding overall health of the animal communities.

What the researchers discovered was encouraging. Over the three-year study, 15 different grizzly bears and 17 different black bears used the crossings. While those may not seem like huge numbers, they represent a significant portion of the populations. Using estimates of the populations of grizzlies and black bears in Banff, these individuals represented close to 20 percent of the population for both species. Previous research estimates that, for large mammals like bears, about 10 percent of a population needs to cross back and forth to ensure a healthy ecosystem. Comparing samples from year to year and in different locations, the researchers can begin to construct family trees for the bears and observe genetic diversity in offspring.

To collect the hair samples, researchers set up lines of barbed wire by several of the crossings. As bears passed, the barbs would snag a bit of hair. To learn about the bears’ movement once they crossed, the team also set up wires near trees that the bears used as scratching posts. Finally, they doused piles of wood 8.5 miles from the highway with cow blood and fish emulsion, a stomach-turning scent for us but an enticing curiosity for the bears. Again, when the bears came to investigate, barbed wire nearby would help keep track of which bears visited.

Over three years, the team collected more than 10,000 strands of bear hair. In addition to finding out that the passageways helped keep the populations healthy, the researchers learned that grizzlies preferred the wide-open overpasses while black bears primarily used the underpasses. Roughly equal numbers of males and females for both species used the crossings, and the genetic sampling lets biologists know more about the population’s family trees. While the team could have chosen any number of species to monitor, they knew there were enough bears to collect significant data and, since scientists are concerned about their declining populations, the data could be relevant in broader studies.

(Read more at High Country News)

#Banff National Park #wildlife #conservation #grizzly bear #black bear #bear #Trans-Canada Highway #Canada #wildlife overpass #highway

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    I’ve driven through these in summer and winter, they’re super cool!
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