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After 25 years, shorebird expert still fights to save the red knot from extinction

Updated: Jul 27, 2023

This article was originally published in NJ Spotlight News.

Conservation measures have pulled the long-distance migrant back from the brink, but its survival is not yet assured

Pictured: Larry Niles

Larry Niles has spent the last 25 years trying to ensure the survival of the red knot and the horseshoe crabs the bird depends on at New Jersey’s Delaware Bay beaches. But he says it’s much too soon to declare victory.

Niles, an independent wildlife biologist who once headed New Jersey’s endangered species program, was shocked to find in the late 1990s that the tiny shorebird’s population had plunged by some 80% because the crab eggs it needs to complete a long-distance migration had been badly depleted by an over-harvest of the crabs for the commercial fishing industry.

The birds’ plight raised the threat of the imminent extinction of the local population of the rusty-red birds, known as “rufa.” That prospect has receded a little over the last quarter-century but is still a possibility despite the efforts of Niles and his associates to make the bay beaches a friendly stopover for the birds on their northbound migration from South America or Florida each May.

Each year since 1997, Niles has led a team of international shorebird experts and volunteers who trap, count, weigh and measure the birds during their roughly two-week visit to the bay beaches, where they rest and feed before continuing their flight to breeding grounds in the Canadian Arctic.

The information allows the team to assess the arrival condition of the birds, some of which have flown nonstop for seven days from southern South America, and to monitor whether they put on enough weight during their stopover to complete a 10,000-mile migration — one of the longest in the avian world — and breed successfully.

Survival not certain

Niles dismissed a suggestion that he has saved the bird from extinction, saying only that the effort has “stopped the bleeding” — a reference to the precipitous fall in the number of both birds and crabs in the late 1990s.

But he said a subset of the 4.7-ounce birds — those that migrate from Tierra del Fuego in southern Argentina all the way to the Canadian Arctic via the Delaware Bay — may still not survive.

“I think there’s still a very good possibility that the long-distance birds are going to die out,” he said in an interview with NJ Spotlight News at Reed’s Beach, a favorite stopover for red knots in Cape May County. “The long-distance population is close to extinction because Delaware Bay resources are too few to allow the population to grow.”

Another group of the rufa birds that migrate from Florida every spring are less dependent on finding food during their Delaware Bay stopover but may be more vulnerable to disease in their wintering grounds, and that raises questions about their survival, too, he said.

Red knots in flight
📷 Credit: (U.S. Fish and Wildlife Service/Public domain)

Thanks to a ban on the crab harvest on the New Jersey side of the bay under a state law passed in 2008, quotas by other bay states, and the closure of some bay beaches to the public during migration, the red knot’s population has crept up to about 30,000 from a low of 17,000 in the late nineties. But that is still only about a third of what it was in the 1980s and early 1990s, Niles said.

That leaves the population well below the level that scientists say would allow the species to survive shocks like bad weather in its Arctic breeding grounds, or new commercial development at other stopover sites on its migration route from South America.

Harvesting horseshoe crabs

But the main threat to the red knot’s survival is a continued shortage of horseshoe crab eggs on Delaware Bay beaches, Niles said.

Crabs are still taken for commercial bait and fertilizer by the fishing industry in Delaware, Maryland and Virginia. But the biggest challenge, Niles said, comes from a handful of so-called bleeding companies that harvest crabs for their blood which contains LAL, a clotting agent used by the pharmaceutical industry to test for bacteria in vaccines, drugs and medical equipment.

Campaigners for the protection of horseshoe crabs, such as the recently formed Horseshoe Crab Recovery Coalition fear the surging production of COVID-19 vaccines has increased demand for crab blood. But they say it’s unclear whether more crabs have been taken during the pandemic because the bleeding companies are unregulated and do not publish crab-harvest numbers.

Even though there’s a synthetic alternative, rFC, that’s effective and cost-competitive, the new product hasn’t been officially endorsed by USP, a trade group that sets professional standards for the American pharmaceutical industry and is key to any decision to switch the industry away from the crab-based product.

“If USP said rFC and LAL were equivalent, and people went to Big Pharma and said, ‘Stop using this animal,’ that would be the end of it,” Niles said.

He estimated that stopping the harvest of crabs for bleeding would save about 500,000 of them a year, mostly females that provide the eggs that sustain the birds.

Ending the bleeding

Ending the bleeding harvest would help Niles hit another metric that he said would significantly increase the birds’ chance of survival: increasing the density of crab eggs on the beaches to 50,000 per square meter, or about five times the current level.

Since 1997, Niles’s campaign has regularly attracted top shorebird biologists from about a dozen countries, all of them drawn initially by the intellectual challenge of understanding why the tiny bird makes one of the avian world’s biggest migrations every year despite the massive odds stacked against it.

As the experts understood more about the bird’s biology, it became clear that the underlying reason for the bird’s decline was the Delaware Bay ecosystem as a whole, Niles said.

Horseshoe crabs
📷 Credit: (Chris Engel from Pixabay)

"What we started to realize was that protecting red knots was really about protecting Delaware Bay. Then we saw that the issues in Delaware Bay aren’t really about the crab itself; it’s the system that’s overfishing the crab is also overfishing all these other species of the productive base,” he said. “What started out as an interesting intellectual problem, that we thought if we studied, we could figure out, turned into an indictment of our system of resource management.”

Niles, a PhD, lives in Greenwich, Cumberland County, with his wife Amanda Dey, principal zoologist with the Department of Environmental Protection’s Endangered and Nongame Species Program, and a regular participant in Niles’s work in the U.S. and overseas.

After taking early retirement from the DEP in 2006, Niles set up his company, Wildlife Restoration Partnerships, to work with government agencies or nonprofits on wildlife projects such as monitoring the red knot population at a coastal site in Brazil so scientists will know the birds’ condition before they arrive at Delaware Bay each year. In another project, the company has applied for federal funding to study the black rail, a secretive wetland bird, on behalf of a client, New Jersey Audubon.

Niles and his team of experts have been joined over the last 25 years by volunteers, some of them from overseas, who love birds and recognize the Delaware Bay as home to one of the world’s great shorebird migration spectacles, which includes semipalmated sandpipers, ruddy turnstones and sanderlings, as well as red knots.

In 2020, COVID-19 kept all but about a half-dozen team members away and the operation is expected to be depleted by the pandemic again this year, but Niles is optimistic that it will be back up to strength in 2022.

Eric Stiles, executive director of New Jersey Audubon, and a former employee of Niles at the DEP, said Niles has attracted loyal experts and volunteers alike because he’s a visionary who recognizes the global nature of shorebird migration.

“There are some real commonalities here, and Larry was able to assemble these people who know what’s going on in other parts of the world,” Stiles said. “If you share a passion for shorebird conservation, you are welcomed with open arms.”

Economic importance to region

He said Niles has also worked to engage people in the Delaware Bayshore community where he lives, by recognizing the economic importance of ecotourism to the region.

“Who would have thought you would have local hotel owners calling up legislators demanding a moratorium on horseshoe crabs?” Stiles said.

Tim Dillingham, executive director of the New Jersey-based American Littoral Society, and a leader of the legislative campaign for the state’s ban on harvesting the crabs, credited Niles for stopping “what looked like sure extinction” for the rufa red knot in the early 2000s, even though it’s still not clear whether the species will survive in the long run.

Along the way, he said Niles has persuaded fisheries regulators to set quotas that incorporate birds as well as crabs.

“He pushed against the status quo, which was to not see the fishing issues as related to the shorebird populations, to push the fisheries regulators to take that inter-relationship into account,” Dillingham said. “Back in the nineties, it was all single-species management.”

At heart, Niles is motivated by his passion for the natural world, Dillingham said.

“He has dedicated his life against these headwinds, these enormous odds, to protecting and restoring this species,” he said. “It’s an act of love — and people don’t like to equate those things when you get into the scientific world. But he has a respect for these animals and a scientific understanding of them, and that’s what motivates his passion.”

Niles himself dismissed a suggestion that after a quarter-century of working for the birds’ survival, he’s frustrated by the fact that it isn’t yet clear whether he will succeed. Rather, he’s focused on his mission.

“I have to see it as part of an exercise that ultimately turns spiritual,” he said. “It’s about investing your life into something meaningful.”

At 69, he said he has no thought of retiring. “I love my work and that’s good enough,” he said. “I hope it will help.”




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