Tens of thousands of migrating shorebirds — dunlins, willets, sanderlings, sandpipers, red knots, ruddy turnstones, plovers, whimbrels — are in a feeding frenzy now on Georgia‘s coast.
On the vast coastal salt marshes, mudflats and barrier beaches, the birds are gorging on countless horseshoe crab eggs, fiddler crabs, clams, marine worms, crustaceans and other nutrient-rich food.
The birds — now in their colorful breeding plumages — are racing against time. Most of them departed in February from winter grounds in Central and South America to head to summer nesting grounds in the Arctic. There, they have only a few weeks of favorable weather to mate, build nests and lay eggs. By July, they will be heading back south.
With its abundant food resources, Georgia‘s coast is a vital stopover for the migrating shorebirds, whose frenzied feeding quickly restores body fat to fuel the rest of their trek up north.
Last weekend, a dozen Atlanta Audubon Society members ventured by boat into the marshes and waterways of one of the coast’s prime shorebird refueling areas, the Altamaha River delta, to watch the amazing feeding spectacle.
An especially abundant and crucial food for the shorebirds is the billions of tiny green eggs laid by horseshoe crabs, now crawling by the thousands onto sandy beaches, sandbars and mudflats to spawn. Scientists say that shorebirds over eons timed their spring migrations to coincide with horseshoe crab egg-laying.
At Egg Island, one of three island wildlife refuges in the mouth of the Altamaha, we saw scores of crabs depositing eggs along the sandy shore. At the same time, a huge flock of semipalmated sandpipers was gobbling up the eggs.
Sanderlings also were feasting. A sanderling weighing 50 grams can eat one horseshoe crab egg every five seconds for 14 hours a day.
Shorebirds are distinguished by their small-to-medium-sized, narrow, pointy bills, long legs, long pointy toes, long wings and unique feeding habits. Other birds of coastal wetlands — herons, gulls, egrets, pelicans, ibises — are not true shorebirds.
Not all shorebirds breed in the Arctic — as we noted from the nesting Wilson’s plovers and American oystercatchers that we saw on sandy shores along the way.
In the sky: The moon will be new Wednesday, said David Dundee, Tellus Science Museum astronomer. Mercury is low in the west just after dark and will appear near the moon Friday morning. Venus rises out of the east about 2 hours before dawn and will appear near the moon Sunday morning. Mars rises out of the east just before dusk. Jupiter is low in the southwest at dusk and sets a few hours later. Saturn rises out of the east at sunset.
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