The Red Knots are arriving for their annual migratory compulsory rest stop and feast on the shores of Delaware Bay . Why so birds fly in from South America to eat here? Deleware Bay is mating grounds for horseshoe crab by the millions. So tens of thousands of migratory shorebirds, who gorge themselves on crab eggs on their way to the Arctic.
The Red Knots are coming from Brazil or Argentina as far south as Tierra Del Fuego from their winter grounds. To prepare for this long annual journey, they shrink their own digestive organs and turn the tissue into fuel to burn in flight. When they arrive on the shores of the Delaware Bay, they are just skin and bones and very hungry.
They time their arrival to perfectly coincide with the annual horseshoe crab spawning here. The crabs lay billions of pearly-green, caviar-sized eggs. Since crab populations could not sustain the vast number of hatchlings in the sea, nature has provided migratory birds to help cull the excess of eggs. Many of these eggs would just dry out or wash away, but instead they become a banquet for the migratory shorebirds including the Red Knots.
In a few weeks of feasting on crab eggs, the red knots will build up enough fat reserves to fuel the last leg of their journey to the Artic. When they fly off, they look like little balls on short legs because of the excess of fat stored under the skin on their breast. By journeys end, they will have flown 10,000 miles from the tip of South America, stopping here to refuel and then fly off to the high Arctic to breed and begin the trek again..
Excerpts courtesy of npr.org/templates/story/story.php?storyId=106511720
Image courtesy of tc.pbs.org/wnet/wp-content/blogs.dir/3/files/2008/06/590_crash_save2.jpg