The number of threatened red knots stopping over in the Delaware Bay this spring is about the same as during the past three migration seasons.
Researchers surveying the birds as they feast on horseshoe crab eggs in the bay recorded about 24,000 birds this season.
That is up from a low of about 14,000 birds in the mid-2000s, when horseshoe crab overfishing depleted the birds’ food supply.
“I think it’s great news, that it’s holding steady,” said biologist Larry Niles, who is working with the American Littoral Society, Conserve Wildlife Foundation of New Jersey and an international research team to survey bird populations.
“It speaks to the work that’s being done on Delaware Bay to help the birds,” Niles said. “We’re rebuilding the stopover, and the birds are responding to that.”
A coalition of conservation groups replenished seven Delaware Bay beaches after superstorm Sandy scoured the sand off many of them, destroying about 70 percent of horseshoe nesting grounds.
Niles’ team has been surveying and tagging the birds as they make their annual migration from South America to their breeding grounds in the Arctic.
The robin-sized shorebird was listed as a threatened species by the U.S. Fish and Wildlife Service this winter.
Niles’ research team is also affixing two new types of geo-locators to the birds this season.
Those tags will record with more precision the migratory path of the shorebird and how they use the Delaware Bay habitat during their stopover.
Niles said that will help scientists more effectively restore and preserve Delaware Bay beaches to make them more hospitable to red knots.