Polar bears are turning to inbreeding and cannibalism to survive the effects of climate change in the Arctic, new studies have revealed
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In this file photo, a young male polar bear waits for the sea ice to return in the Churchill Wildlife Management Area, in Manitoba on Oct. 27, 2020.
Scientists have noted that ‘rapid sea ice loss in the Arctic Barents Sea’ has led to the loss of 10 per cent of genetic diversity in the polar bear population of Norway’s Svalbard Archipelago, between 1995 and 2015, states the study, published by The Royal Society journal on Sept. 8.
Examining the DNA of 622 polar bears in the archipelago, they found that the group had grown more genetically distinct from polar bears seen at other areas in the Arctic.
Simultaneously, the polar bears had also grown more genetically distinct from the polar bears found at other sites in the Arctic, indicating the bear populations found in the same location are becoming more genetically similar.
Declining sea ice coverage, the study explained, leads to habitat fragmentation, forcing polar bears to mate with others within a smaller area, resulting in inbreeding.
“With genetic diversity, when the population becomes so small, you’ll find that there will be a higher chance of closely related individuals mating and producing offspring. But with that comes risk in the sense that some of the traits that are recessive, will now basically be unmasked in the population,” the study’s author Simo Maduna, of the Norwegian Institute of Bioeconomy Research, told ABC News.
As the animals become more isolated from each other, this “may increase inbreeding in the future, most likely with negative effects such as inbreeding depression,” the study said.
A second study , released in April, found that climate change has severely disrupted the dietary habits of the polar bear population, forcing them to prey on seabirds and eggs instead of seals. However, due to lack of experience, most bears observed were not “efficient” seabird egg predators, the study found, noting that instead of visiting multiple nests, bears would often visit the same empty nest multiple times.
In some areas of the Arctic suffering from a lack of food sources, bears have become increasingly cannibalistic, experts say. The disappearing sea ice, Russian scientist Ilya Mordvintsev said , has forced the bears onshore instead of in the water hunting seals, consequently turning to food sources on land.
“Cases of cannibalism among polar bears are a long-established fact, but we’re worried that such cases used to be found rarely while now they are recorded quite often,” Mordvintsev said at a presentation in St. Petersburg.
“We state that cannibalism in polar bears is increasing…. In some seasons, there is not enough food and large males attack females with cubs.”
Scientists have noted that ‘rapid sea ice loss in the Arctic Barents Sea’ has led to the loss of 10 per cent of genetic diversity in the polar bear population of Norway’s Svalbard Archipelago, between 1995 and 2015, states the study, published by The Royal Society journal on Sept. 8.
Examining the DNA of 622 polar bears in the archipelago, they found that the group had grown more genetically distinct from polar bears seen at other areas in the Arctic.
Simultaneously, the polar bears had also grown more genetically distinct from the polar bears found at other sites in the Arctic, indicating the bear populations found in the same location are becoming more genetically similar.
Declining sea ice coverage, the study explained, leads to habitat fragmentation, forcing polar bears to mate with others within a smaller area, resulting in inbreeding.
“With genetic diversity, when the population becomes so small, you’ll find that there will be a higher chance of closely related individuals mating and producing offspring. But with that comes risk in the sense that some of the traits that are recessive, will now basically be unmasked in the population,” the study’s author Simo Maduna, of the Norwegian Institute of Bioeconomy Research, told ABC News.
As the animals become more isolated from each other, this “may increase inbreeding in the future, most likely with negative effects such as inbreeding depression,” the study said.
A second study , released in April, found that climate change has severely disrupted the dietary habits of the polar bear population, forcing them to prey on seabirds and eggs instead of seals. However, due to lack of experience, most bears observed were not “efficient” seabird egg predators, the study found, noting that instead of visiting multiple nests, bears would often visit the same empty nest multiple times.
In some areas of the Arctic suffering from a lack of food sources, bears have become increasingly cannibalistic, experts say. The disappearing sea ice, Russian scientist Ilya Mordvintsev said , has forced the bears onshore instead of in the water hunting seals, consequently turning to food sources on land.
“Cases of cannibalism among polar bears are a long-established fact, but we’re worried that such cases used to be found rarely while now they are recorded quite often,” Mordvintsev said at a presentation in St. Petersburg.
“We state that cannibalism in polar bears is increasing…. In some seasons, there is not enough food and large males attack females with cubs.”
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