Red knot birds need our assistance

As most of us eagerly await the end of winter, some residents of Tierra del Fuego at the southern tip of South America prepare for the end of the austral summer. Red knots, a small migratory shorebird, are experiencing a predictable sensation of pre-migratory restlessness. Having just molted into breeding plumage, red knots will soon begin a 20,000 mile trip to their arctic nesting grounds.

The journey begins with a 1,700-mile leg along the east coast of South America. Then they cross Brazil before striking out across the open Atlantic Ocean to the east coast of North America, a journey of about 7,000 miles. Many reach the Delaware Bay in mid-May. The final leg of the trip covers about 1,000 miles to their arctic breeding grounds.

The journey requires dependable food supplies along the way. But the stop at the Delaware Bay is critical. Here red knots nearly double their body weight to prepare for the physiological demands of migration and nesting. Timing is everything; knots reach the Bay just as horseshoe crabs leave the deep ocean waters and come ashore to breed and lay eggs. It is the horseshoe crab eggs that fatten and fuel the red knots.

In an amazing display of ecological synchronicity that has been taking place for eons, red knots reach the Delaware Bay just as horseshoe crabs spawn. The intersection of these journeys has long fascinated scientists and birders. It’s a primary reason birders flock to south Jersey in May. The sight of tens of thousands of birds on a beach or in the sky is breathtaking.

But about 15 years ago ornithologists began to notice that knot numbers were declining. The problem, superbly depicted in a recent episode of PBS’s “Nature,” is an overharvest of horseshoe crabs.

Horseshoe crabs, more closely related to spiders than crabs, are familiar to anyone who has walked an east coast beach in May or June. Despite a ferocious appearance, they are harmless. But watermen who harvest conchs and eels use them for bait.

Initially, horseshoe crabs were taken in modest numbers, but about 10 years ago, watermen began collecting them by the truckload as they came ashore to spawn. Since horseshoe crabs require about nine years to attain sexual maturity, such a sudden overharvest of breeding individuals had devastating consequences. Fewer breeding horseshoe crabs laid fewer eggs, which fed fewer red knots. Knots couldn’t gain the weight necessary to successfully nest, and the knot population began to decline.

Today red knot numbers stand at critically low levels. In a Feb. 11 story in the Newark Star-Ledger, Kathleen Clark, senior biologist with New Jersey’s Endangered and Non-Game Species Program, was quoted saying, “The news from South America is not good. Surveys show a 30 percent drop in the red knot populations since last year.”

The story goes on to report that the entire Western Hemisphere red knot population is estimated to be 18,000 to 33,000 birds compared with 100,000 to 150,000 just 20 years ago.

New Jersey’s nine-member Marine Fisheries Council seems unimpressed. Just a few days ago it voted 5-4 voted against extending a two-year-old moratorium on horseshoe crab harvests. Five commercial fishermen voted against the moratorium extension; four recreational fishermen on the council voted for it. This debate clearly pits science against the commercial interests of a relatively few watermen. The simplest solution would be for the U.S. Fish and Wildlife Service to protect red knots under the provisions of the Endangered Species Act. The Service, however, has “… determined that the red knot warranted protection, but placing it on the endangered species list is precluded by higher priority listing actions for species at greater risk.” That’s code for political interference.

This is a hot issue. Letters to New Jersey’s Gov. Jon Corzine (P.O. Box 001, Trenton, NJ 08625), especially from out-of-state, nature-minded tourists, might convince him to listen to the advice of his Department of Environmental Protection. If you choose to write a letter, do so as a private individual. Do not mention this column, and do not ally yourself with any conservation group. Letters from individuals carry more weight than those generated by an organization.

X Send questions and comments to Dr. Scott Shalaway, RD 5, Cameron, WV 26033 or via e-mail my Web site, http://scottshalaway.googlepages.com.