"What we saw this season for Caspian terns is another example of the fragility of the Arctic system." - Peter Zahler
Caspian terns — a striking white shorebird species that sports a black cap and long red-orange bill — have ventured into new territory this year.
Scientists were recently surprised to find a Caspian tern nest in northern Alaska, 1,000 miles further north than the species has previously been recorded.
"What we saw this season for Caspian terns is another example of the fragility of the Arctic system," said Wildlife Conservation Society Regional Director Peter Zahler in a press release.
In a departure from the usual reports on shorebird declines, Caspian tern populations have actually been on the rise in recent years. Observations of breeding Caspian terns in Alaska — a rare occurrence three decades ago — have become common, though until now, they had never been seen farther north than the Neragon Island in the southern Bering Sea.
But with summer sea ice dwindling and a longer snow-free season, temperate species are taking the opportunity to expand their ranges northward.
"The challenge for scientists is to help understand the repercussions of these changes,” says Wildlife Conservation Society researcher Martin Robards. “For example, we've seen red foxes take over areas previously used by arctic foxes.”
“We don't know what the repercussions of new colonies of Caspian terns will be on the current resident species, particularly if they gain more of a foothold and expand their numbers.”
In other regions, Caspian tern population spikes have been placing heavy pressure on local fish stocks.
“Adaptation of wildlife and people to new conditions in the Arctic represents one of the most significant challenges for conservationists and local communities, not just in the future but right now,” says Zahler, who is pushing for continued monitoring of the Caspian terns to inform the development of tools that will “support adaptation planning for both wildlife and people."
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