Stranded Polar Bears Threaten Migratory Birds


Image credit: Tomi Tapio/Flickr

With their habitats shrinking, and new competitors moving in, polar bears across the Arctic are desperate to find a place to feed, rest, and raise their cubs. In Canada, this has led to an increase in polar bear-human interactions. On the island of Svalbard, north of Europe, it has placed another species—barnacle geese—in danger.Svalbard barnacle geese spend their summers nesting on the island. The birds are long-lived, but infrequent breeders—and even if they do lay eggs, the typically small clutch sizes mean that only a few chicks join the flock each year.

Added to this already low breeding rate is a new challenge: Hungry polar bears.

This year, 10 polar bears were stranded on the island after Arctic ice melted. Hungry and trapped, the marauding bears began feeding on the eggs of the barnacle geese. One bear was observed eating more than 1,000 eggs.

Indeed, the impact has not been insignificant. Of the more than 500 nests holding eggs on the island this summer, fewer than 40 were successful—with the majority of those producing only one or two chicks.

Just 60 years ago, the goose population on Svalbard had dipped below 300. After decades of conservation work, the population has climbed above 30,000. This most recent threat, however, could jeopardize that seemingly robust number.

Researchers hope that the geese will adapt to the presence of bears in the future. Brian Morrell, a zoologist with Wildfowl and Wetlands Trust, explained:

Some of the goose colonies in Svalbard use cliffs to nest. Although that has its own problems for fledgling chicks, it does put the nests out of reach of marauding bears.

In spite of the challenges, Morrell said, it may be the only strategy left to the geese if bears continue to call the island home.

Read more about polar bears:
Melting Ice Increasing the Chance of Polar Bear-Human Meet-Ups
Grizzlies Move into Polar Bear Territory
Starving Polar Bears Turning to Cannibalism
Global Warming Not the Only Thing Threatening Polar Bears

Tags: Conservation | Endangered Species | Global Warming Effects

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