Tuesday, May 24, 2011

Some Red Knot News

Last week, I had the privilege of helping with Red Knot banding in Cape May. A reporter from my local newspaper spent some time with the shorebird banding crew recently and filed a story on the current status of Red Knots. Things are still looking dire, despite some New Jersey's moratorium on the horseshoe crab harvest.
Now the federal government might make a decisive move. The red knot is a priority in a new plan by the U.S. Fish and Wildlife Service to deal with a backlog of 250 animal and plant species proposed to be covered by the Endangered Species Act....

But meanwhile, horseshoe crab harvests in other states might be increased when the Atlantic States Marine Fisheries Commission meets later this year, she added. And scientists are concerned because a key crab survey by Virginia Tech lost its federal funding this year and is just halfway toward raising the $200,000 cost.

Delaware Bay is the big stopover for red knots’ flying north to breeding grounds in Canada, because their migration coincides with the horseshoe crab breeding season that leaves bay beaches littered with nourishing crab eggs. That fattens the birds and gives them energy to push on north and lay eggs, said Niles, chief scientist for the Conserve Wildlife Foundation of New Jersey....

New Jersey shut down its commercial fishery for horseshoe crabs in 2006, culminating years of cutbacks after the take of crabs for fishing bait was blamed for the red knots’ decline. But after 6,000 birds went missing from their South America wintering grounds, researchers think the problem may be down south, Niles said.

Researchers in Argentina reported toxic red tide algae blooms may have killed some birds before they reached their winter quarters, at the southern tip of the continent at Tierra Del Fuego. The drop in the winter count, to 10,000 birds from 16,000, may show growing dangers to the birds all along the western Atlantic and Caribbean shores, said Niles, a former chief of New Jersey’s endangered wildlife program.
Banded shorebirds now carry small flags that can be read with a spotted or from a photographic image. These flags, along with any codes they bear, should be reported at bandedbirds.org. Here is some background information on the website
“If you are the first one to see the re-sighting, we know the bird is still in the flyway,” said Jeannie Parvin, who manages the website www.bandedbirds.org. “Just that information is very important. It’s not just for red knots, it’s for all the shorebirds.”
The website supports the Delaware Bay Shorebird Project, a 15-year effort that has built perhaps the world’s biggest database on migrating shorebirds within a flyway. Like a highway for people, a flyway is a track that birds follow between their southern winter homes and summer nesting grounds in the high Arctic of Canada.

Bandedbirds.org offers pages explaining shorebird research, how to read tags on birds and estimate bird counts. After a one-time registration, contributors can send in sightings that go immediately into a database for researchers to use, Parvin said.
Finally, there has been some research into the feasibility of raising horseshoe crabs from eggs in captivity and releasing them once they are better able to survive predation.
Woodruff works at the university's aquaculture facility in Lower Township, where the staff cultivates oysters. But they are looking to expand their scope to raise horseshoe crabs from eggs for release back into the wild to give the creatures a head-start against hungry predators.

"Everything eats them. Basically, we want to farm them - take their eggs and raise them until they are big enough to survive on their own," Woodruff said.

Such human intervention could solve a conflict between local fishermen and conservationists. New Jersey's ban on crab harvesting remains in place in a bid to build up the number of spawning crabs and their bounty of eggs, which are critical for feeding rare shorebirds such as red knots that gather on the bay to fatten up during their epic migrations from the Arctic to South America.

Daniel Hernandez, an assistant professor at The Richard Stockton College of New Jersey, counts crab eggs on the beach each year for his ongoing research. The Stone Harbor resident said egg counts have dropped precipitously from their historic levels....

A 2009 study in the journal BioScience, which Hernandez took part in, said that in 1990 more than 100,000 crab eggs per square meter were found on Delaware Bay beaches.

"Now they have 5,000," he said.
I hope that works to rebuild their numbers because the number of horseshoe crabs eggs is critically low to support Red Knots and the other shorebirds that depend on them. The same news article mentions that there will be horseshoe crab tagging sessions open to the public at 8:30 pm on May 31 and June 2 at Kimbles Beach in Cape May NWR. If you're in the area, it might be worth checking out.