Red Knot (Calidris canutus)
Imagine a beach so densely packed with shorebirds that sunlight is blocked from the sand. If that beach were on Delaware Bay in mid-May, the shorebirds - numbering in the hundreds of thousands - would be red knots.
Separating New Jersey from Delaware on a coastline pressured by rapid suburban growth, Delaware Bay serves migrating knots as a crucial stepping-stone. En route to the Arctic from their South American wintering grounds, these chunky "beach robins" time their arrival to coincide with the breeding cycle of the bay's horseshoe crabs. Every May hordes of these ancient invertebrates haul themselves from the surf to deposit eggs by the millions in holes they have scooped in the sand. Knots, ruddy turnstones, and other shorebirds depend on these eggs to refuel their northward flights. The birds stay several weeks, gorging on the eggs from dawn until dusk to increase their body weight by 40% or more. Finally sated, they whirl off again in huge clouds toward the Arctic.
How many birds can convene on Delaware Bay? During the month of May alone, a million birds may comb the bay's egg-laden shores. On a given day during that period, more than 80% of North America's Red Knots - and half its ruddy turnstones - may join ranks there in one of the world's most awe inspiring congregations of wildlife.
Reader's Digest: Book of North American Birds
No comments:
Post a Comment