Polar bears in poor condition
Icy hunting grounds diminishing: Report
Peter Gorrie
Toronto Star
http://www.thestar.com/News/article/167748
Polar bears in Ontario's far north are in much worse shape than 20 years ago, likely because climate change is melting the ice from which they hunt, says a new report by a provincial government scientist.
The decline in their physical condition is almost certainly a first step toward a population reduction, says the report, headed by Martin Obbard of the Ministry of Natural Resources in Peterborough.
These are "pretty clear warning signals," Obbard said.
The connection to climate change isn't certain, but the problem appears to be that Hudson Bay is melting earlier in spring and freezing later in fall.
Polar bears spend the winter on the ice, hunting ring seals and putting on body fat. In summer, they travel up to 40 kilometres inland, eating little. That's when females give birth and nurse their young.
They run into trouble if they haven't been able to eat enough seal to provide energy for those lean months. With less ice, they have less time to hunt.
"At a personal level ... I don't think there's any doubt," that the lengthening ice-free season is the culprit, Obbard said.
Similar results have been reported for bears on the Manitoba shore of the bay: Obbard's report is the first to show an impact on the 1,000 or so along the 600-kilometre stretch of Ontario shoreline from north of the native community of Attawapiskat up to the Manitoba border.
From 2000 to 2005, the researchers measured the size and weight of polar bears they drugged using tranquilizer darts fired from a helicopter. Those results were used to determine the animals' body condition, then compared to findings from the early '80s.
The most dramatic decline was in pregnant females, followed by juvenile bears. Adult males were also in worse shape, but hadn't declined quite as badly.
The number of Manitoba bears has fallen from about 1,200 to 975 in the past 25 years. Obbard's results suggest Ontario bears will "follow the same trajectory," with poor condition followed by reproductive failure, then a drop in population.
"I can't say how imminent it is, but it's happening," he said.
Informant: binstock
http://freepage.twoday.net/search?q=polar+bears
Peter Gorrie
Toronto Star
http://www.thestar.com/News/article/167748
Polar bears in Ontario's far north are in much worse shape than 20 years ago, likely because climate change is melting the ice from which they hunt, says a new report by a provincial government scientist.
The decline in their physical condition is almost certainly a first step toward a population reduction, says the report, headed by Martin Obbard of the Ministry of Natural Resources in Peterborough.
These are "pretty clear warning signals," Obbard said.
The connection to climate change isn't certain, but the problem appears to be that Hudson Bay is melting earlier in spring and freezing later in fall.
Polar bears spend the winter on the ice, hunting ring seals and putting on body fat. In summer, they travel up to 40 kilometres inland, eating little. That's when females give birth and nurse their young.
They run into trouble if they haven't been able to eat enough seal to provide energy for those lean months. With less ice, they have less time to hunt.
"At a personal level ... I don't think there's any doubt," that the lengthening ice-free season is the culprit, Obbard said.
Similar results have been reported for bears on the Manitoba shore of the bay: Obbard's report is the first to show an impact on the 1,000 or so along the 600-kilometre stretch of Ontario shoreline from north of the native community of Attawapiskat up to the Manitoba border.
From 2000 to 2005, the researchers measured the size and weight of polar bears they drugged using tranquilizer darts fired from a helicopter. Those results were used to determine the animals' body condition, then compared to findings from the early '80s.
The most dramatic decline was in pregnant females, followed by juvenile bears. Adult males were also in worse shape, but hadn't declined quite as badly.
The number of Manitoba bears has fallen from about 1,200 to 975 in the past 25 years. Obbard's results suggest Ontario bears will "follow the same trajectory," with poor condition followed by reproductive failure, then a drop in population.
"I can't say how imminent it is, but it's happening," he said.
Informant: binstock
http://freepage.twoday.net/search?q=polar+bears
rudkla - 7. Jan, 22:34
