The red knot, a robin-sized bird that visits the Delaware Bayshore a couple weeks each year, will soon be listed as a threatened species under the Endangered Species Act. The red knot population has plunged since the 1980s, due to habitat loss, declining food sources and the effects of climate change.
The red knot is a small bird identifiable by fluty birdsong and the reddish plumage that extends from the face to its breast during breeding season. Every year, flocks of red knots make their way from the Canadian arctic to the southeastern United States, then down to South America then return with a stop along the Delaware Bayshore. For some red knots, this migratory trek can span over 18,000 miles.
The bird’s populations have dropped 75 percent since the 1980s. For many years, the red knot was a candidate for protection under the Endangered Species Act. It was proposed officially in 2013 that it be protected as a threatened species.
In the past, a major threat to red knots was overfishing of horseshoe crabs, whose eggs are a significant food source for them. While horseshoe fishing regulations have stabilized red knot numbers, Wendy Walsh, a senior biologist with the Fish and Wildlife service, says the main threats to the species now is rising seas and climate change.
“Horseshoe crab threat is being adequately managed at this time," said Walsh. "But we now have reduced population levels so now additional threats that were ongoing and maybe worsening are now acting on a reduced population. These include habitat loss from development and sea level rise as well as other changes related to climate change.”
Walsh also notes the red knots have also started arriving at the Delaware Bay later than usual, putting the bird out of sync with when horseshoe crabs are abundant.
“Some of the birds are arriving later and scientists still aren’t sure why that occurred. But that did worsen the situation because they have such a brief stop here that with less time and less food, increasing percentage of them were not able to gain enough weight to finish their migration,” said Walsh.
The threat to the red knot was arguably the most important reason that Mispillion Harbor was selected in mid-June for $4.5 million in federal funds for post-Sandy restoration that will help restore and protect shoreline used by the bird during their migration.
The red knot will officially become a threatened species in early January. The species can be found across 27 countries and 40 states of the United States.
