Reindeer swimming in the Alaskan Arctic
Tom Walker / Alamy
Animals in the Arctic, including reindeer and golden eagles, are earlier migrating due to climate change, say researchers, who have gathered a large amount of data to study the behavior of 86 Arctic species over the past three decades.
“We can monitor animal movements on a very large scale,” says Eliezer Gurarie of the University of Maryland. “It seems that animals react unwittingly and adapt to climatic changes, and have done so for years.”
Gurarie and his team used GPS tags and satellites to track the spring migration of more than 900 female reindeer over the past 15 years. They discovered that the females migrate to give birth about a day earlier in the year, likely due to the warming temperatures.
“These patterns track global warming,” he says. The Arctic is experiencing some of the worst effects of climate change and is warming twice as fast as the global average.
Earlier birth times can be risky in northern parts of the Arctic, says team member Gil Bohrer of Ohio State University. “These offspring are more likely to face strong freak storms,” he says. If they do, many will inevitably die from being unable to cope with extreme conditions that can see up to half a meter of snow.
Reindeer are already in decline, says Gurarie, and climate change is making things worse. This poses a threat to the people living in the area who rely on them for fur and meat.
Similarly, golden eagles – which normally nest on the arctic tundra – have started their spring migration half a day earlier each year for the past 25 years.
“The daily differences in climate change are very small,” says Bohrer. “Understanding how animals react to climate change takes a very long observation time – something that has only recently been possible.”
The Arctic Animal Movement Researchers’ Archives currently contain more than 15 million data points on 8,000 animals. “Our archive can help recommend management techniques for conserving endangered species, as climate change will only get more extreme,” says Bohrer.
Journal reference: Science, DOI: 10.1126 / science.abb7080
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