Saturday, May 30, 2009

Red Knots Gaining More Weight in 2009

Red Knot, originally uploaded by Birdfreak

This report from the APP suggests that the Red Knot situation may be stabilizing.
At less than a quarter-pound, each sanderling could easily fit in a coffee cup. But for these shorebirds, it's good to be overweight; their May feast on Delaware Bay gave them enough fuel for the last leg of their annual, hemispheric flight.

"Hitting over 100 grams is very good. Some of these birds can barely fly. So they're in great condition," scientist Larry Niles told Rutgers University students Wednesday, after they helped weigh and tag one of the biggest captures this spring by the Delaware Bay Shorebird Project.

For the first time in a decade, red knots and other migrating shorebirds appear to be finding enough horseshoe crab eggs in Delaware to achieve critical weight gain, Niles said.

"We're extraordinarily pleased with what's happened," said Larry Niles, a biologist with the Conserve Wildlife Foundation of New Jersey and the former chief of New Jersey's endangered species program. "We've had unusually settled weather the last couple of weeks, low onshore winds. So it was a soup of crabs."

The birds have gained weight so fast that researchers anticipate they will lift off this week to head for their summer breeding grounds in the Canadian Arctic, said Amanda Dey, who heads the shorebird effort for the state Department of Environmental Protection.
Weight gain is critical for shorebirds since they will need to excess fat for a nonstop flight to their Arctic breeding grounds. Without that fat, they may not be able to complete the journey or they may arrive too exhausted and famished to breed. The brevity of Arctic summer means that shorebirds must follow an even stricter schedule than other bird species. Those that cannot breed right away may not breed at all.

So this is very good news:
The birds have had a good time on their Delaware Bay stopover, according to weighing data compiled by the team. In past years many birds failed to reach what researchers considered minimum safe weights to survive the flight north.

But graphs showing this year's weights show many more birds hitting the optimums. Observers have seen much less activity at Stone Harbor on the ocean side of Cape May County, where large numbers of shorebirds congregated in recent springs, and researchers believed they were feeding on mussels to make up for shortfalls in crab eggs.
Of course, Red Knots are not out of the woods yet. One good spring eating season just gives them a better chance at preventing further losses. There is certainly a long way to go to recovery. But given the dire outlook for these birds just a few years ago, it is a hopeful sign that conservation measures are starting to have effect.

Reported any banded or color-tagged shorebirds to The banding studies help scientists to understand more about the birds' movements and habitat needs.