Shifts
in the distribution of Spectacled Eiders, a predatory bird at the top of the
Bering Sea’s benthic food web, indicate possible changes in the Arctic’s marine
ecosystem, according to new research in The Condor: Ornithological Applications.
Matt
Sexson of the USGS Alaska Science Center and his colleagues compared recent
satellite telemetry data from molting eiders with data from the mid-1990s. They
found that in two of the species’ four primary molting areas, the birds have
shifted their range significantly in the intervening decades, and the
researchers interpret this as an indicator of ecosystem change–eiders go where
their prey is, and their movements could indicate big changes in the community
of bottom-dwelling, cold-water-dependent invertebrates they eat.
It’s
easier to track marine predators than it is to track their prey, explains
Sexson. “It’s tough to speculate on the connection with climate change because
the data are so sparse, but we know that the north Pacific is changing,” he
says. “There’s a lot of corresponding evidence that together all says something
big is happening here, and eiders provide a readily available indicator that
changes are occurring.”
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