Defenders' Experts
Red Knots: In the Field
If you live in the Delaware Bay area and want to get involved, please click here for a list of the array of projects that need volunteers.
Defenders has provided funding to the New Jersey Department of Environmental Protection for their monitoring efforts. In June 2006, we provided $5,000 for their survey of radio-tagged red knots on their Canadian arctic breeding and migrating grounds. Accurate monitoring of red knot populations will be key to securing greater protections in order to halt or reverse their decline.
There are three primary wintering areas for the knot, two in South America (Chile and northern Brazil), and one in Florida. It was not known whether these wintering populations were genetically distinct in their Arctic breeding areas. In other words, are red knot wintering populations breeding in distinct areas of the Arctic and not interbreeding?
The complexity of the red knot migratory ecology and the remoteness of both wintering and breeding areas made this question difficult to answer. But this summer, thanks in part to Defenders funding, a team of biologists tracked Florida-wintering red knots outfitted with radio transmitters. The team included Drs. Larry Niles and Amanda Dey of the New Jersey Division of Fish and Wildlife, Dr. Jim Fraser of Virginia Tech and Dr. Dan Hernandez of Stockton College. After a week in the Arctic and a flight that lasted three days covering most of the Canadian Arctic Archipelago, they found no evidence of breeding-range overlap between Florida and South American knots, suggesting each wintering population breeds in different Arctic locations.
Most wildlife depends on robust populations with sufficient genetic diversity to avoid the perils of inbreeding. As population numbers decline the danger grows and at critical thresholds there may not be sufficient genetic diversity to overcome even minor population calamities. Population Geneticist Dr. Allan Baker theorizes that when shorebird numbers decline below 15,000 birds, even the most aggressive conservation program cannot overcome the impact of low genetic diversity. The New World red knot population now stands at about 20,000 breeders. If one divides that total number into separate breeding populations, then the danger of inbreeding increases dramatically.
There are additional benefits to this work. As a consequence of the Arctic study, the team suspected that a second southbound route must exist east of James Bay, the only known southerly flyway in Canada. Working with Canadian Fish and Wildlife biologists, a new red knot stopover was found in the Mingan Archipelago, a small chain of islands in the Gulf of St. Lawrence. With additional funding from Defenders, a small team composed of L. Niles, A. Dey, Mark Peck from the Royal Ontario Museum and Steve Gates, a volunteer with the Delaware Bay Shorebird Project, went to the islands and spent nearly a week tracking knots and scanning for individually marked birds to determine wintering area affiliations. To everyone’s surprise, the knots included birds from Florida as well as South America. These data will be used to propose the Mingan Island as a new Western Hemisphere Shorebird Reserve.
In May and September of 2005, Defenders awarded a total of $15,575 to the Conserve Wildlife Foundation of New Jersey to assist their volunteer program of protecting red knots on New Jersey beaches from disturbances and to construct experimental gull exclosures. Gulls compete with red knots for horseshoe crabs.
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