Team Work to Help the World's Polar Bears
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Amstrup notes that aerial surveys are quick and noninvasive. They would be useful for the future monitoring of the Western Hudson Bay polar bears and of other polar bear subpopulations that spend predictable periods on land.
"With climate warming going on, we may start to see increasing numbers of subpopulations that are stuck on land for periods of time, so the utility of such a method is likely only to expand in the future," he says. "Before we start assessing bears through aerial surveys, though, we first need to verify that this method of enumeration really works. The Western Hudson Bay population gives us that opportunity."
Western Hudson Bay
Dr. Nick Lunn of the Canadian Wildlife Service says that the Western Hudson Bay polar bear population lives near the southern limit of the distribution of the species. As a result, these bears are more vulnerable to changes in ice formation as a consequence of environmental or climatic fluctuations.
"Since the early 1980s, the condition and natality of this population of polar bears have been declining," Lunn says. "These declines appear to be directly related to a trend towards the earlier breakup of sea ice in western Hudson Bay, due to warmer spring temperatures, which reduces the time that polar bears have access to seals."
Lunn adds that the effects of long-term climatic change are not restricted to polar bears in Western Hudson Bay, but will also affect polar bears throughout the circumpolar Arctic. The Western Hudson Bay population, however, is the only one for which sufficient data currently exist to examine trends and determine effects. For this reason, it's important that the studies there continue.
The research objective, says Lunn, is to capture an annual sample of polar bears in fall (of all age and sex classes) and spring (females with new cubs) to determine whether the declining trend in both cub production and body condition, which has occurred over the past 20 years, is continuing or has stabilized. This will provide scientists with timely data that will assist them in the ongoing, long-term conservation and management of polar bears in Western Hudson Bay.
Chukchi Sea Population
Polar bear scientist Scott Schliebe of the U.S. Fish & Wildlife Service says that baseline data on the Chukchi Sea polar bear population—which is shared by the U.S. and Russia—is urgently needed. "The increased harvesting of polar bears in Chukotka, Russia, raises serious concerns about the status of this population," he says. "We've had persistent reports of high harvests over the past few years. Some estimates place the harvest as high as 200-400 bears per year."
"With climate warming going on, we may start to see increasing numbers of subpopulations that are stuck on land for periods of time, so the utility of such a method is likely only to expand in the future," he says. "Before we start assessing bears through aerial surveys, though, we first need to verify that this method of enumeration really works. The Western Hudson Bay population gives us that opportunity."
Western Hudson Bay
Dr. Nick Lunn of the Canadian Wildlife Service says that the Western Hudson Bay polar bear population lives near the southern limit of the distribution of the species. As a result, these bears are more vulnerable to changes in ice formation as a consequence of environmental or climatic fluctuations.
"Since the early 1980s, the condition and natality of this population of polar bears have been declining," Lunn says. "These declines appear to be directly related to a trend towards the earlier breakup of sea ice in western Hudson Bay, due to warmer spring temperatures, which reduces the time that polar bears have access to seals."
Lunn adds that the effects of long-term climatic change are not restricted to polar bears in Western Hudson Bay, but will also affect polar bears throughout the circumpolar Arctic. The Western Hudson Bay population, however, is the only one for which sufficient data currently exist to examine trends and determine effects. For this reason, it's important that the studies there continue.
The research objective, says Lunn, is to capture an annual sample of polar bears in fall (of all age and sex classes) and spring (females with new cubs) to determine whether the declining trend in both cub production and body condition, which has occurred over the past 20 years, is continuing or has stabilized. This will provide scientists with timely data that will assist them in the ongoing, long-term conservation and management of polar bears in Western Hudson Bay.
Chukchi Sea Population
Polar bear scientist Scott Schliebe of the U.S. Fish & Wildlife Service says that baseline data on the Chukchi Sea polar bear population—which is shared by the U.S. and Russia—is urgently needed. "The increased harvesting of polar bears in Chukotka, Russia, raises serious concerns about the status of this population," he says. "We've had persistent reports of high harvests over the past few years. Some estimates place the harvest as high as 200-400 bears per year."