Piping plovers are making a modest comeback in New Jersey after hitting a low of 92 pairs in 2014, but now scientists are nervously awaiting word of how they survived Hurricane Irma at their wintering grounds in the Caribbean and Florida.
About 40 percent of the East Coast population winters in the Bahamas, with the rest going to other Caribbean islands and to the southeast United States from the Carolinas to Florida, said Christina “Kashi” Davis, 40, an environmental specialist with the state Division of Fish and Wildlife in its Endangered and Nongame Species Program.
“We’re definitely nervous for this year. We know (Hurricane) Irma didn’t directly hit the Bahamas, and that’s good news. But it sure hit in Cuba,” Davis said. “And south Florida birds, we are very worried about.”
In 2016, 115 pairs of the tiny beach nesters were counted from Sandy Hook to Cape May, and the number fell to 105 this year.
The species is particularly affected by human activity, often abandoning nests if there is too much foot or other traffic.
And because they lay their eggs on top of the sand, predation by foxes, raccoons, feral cats and even other birds is a huge problem. They are so small, they cannot even dig their eggs out after a storm blows too much sand over them, said Davis.
About half of the pairs this year were in northern Monmouth County, with fewer and fewer in the southernmost part of the state, she said.
“I’m extremely concerned about Cape May County,” Davis said. “It feels like a death spiral (there).”
The county hosted about 40 pairs in the early 2000s, she said.
But by 2017, there were just four pairs in the entire county, from Ocean City to Cape May — three in Stone Harbor and one in Avalon, Davis said.
Only one chick fledged — out of the Avalon nest. The pairs in Stone Harbor didn’t even hatch any eggs, she said.
Researchers don’t fully understand why the birds have disappeared from so much of the county, failing to find their way to good beach habitat there. There are plenty of theories, though.
“They come back to areas where they hatched. So if the area’s not hatching chicks, there are none to come back,” said Davis. “Piping plovers don’t live very long. They breed in the first to second year, so we need to constantly replace chicks.”
Vegetation may need to be removed from the beach at the Nature Conservancy’s South Cape May Meadows, said U.S. Army Corps of Engineers biologist Beth Brandreth, who helped design the beach for piping plovers in a restoration project there years ago.
The statewide numbers are considerably lower than the high of 144 pairs in 2003, and lower than the long-term average of 119 to 120 pairs, said Davis.
Endangered in New Jersey and threatened in the United States, piping plovers are monogamous within a season, but sometimes switch partners in subsequent seasons, according to the state Department of Environmental Protection.
They are counted in pairs because it’s the best way to assess the population, Davis said.
“We also do count by individual, but since we are on the breeding grounds and are concerned with recovery of the species, the number of birds paired up actively trying to reproduce is a better indicator of where we stand,” she said.
“There are always some bachelor birds that do not find a mate, as well as pairs that never manage to breed,” Davis said, so the total is greater than the number of pairs doubled. Individual numbers for this season are not yet fully tallied.
This summer the species returned to Island Beach State Park in Ocean County for the second year in a row. A single pair fledged two chicks there last year and one chick this year, after more than a decade of no successful nests there, according to the state Department of Environmental Protection.
In Atlantic and southern Ocean counties, the Holgate and Little Beach sections of Forsythe National Wildlife Refuge had mixed results, and the state-owned North Brigantine Natural Area improved.
Holgate, at the southern tip of Long Beach Island, went from six pairs in 2011 to 25 pairs in 2016 and fell to 22 this season, while the numbers in Little Beach, a small island north of Brigantine, fell from 17 in 2011 to 12 in 2016, then rebounded to 15 this year.
The Holgate site in particular benefited from a huge overwash of sand from Hurricane Sandy and a northeaster, creating a wider sandy beach for the birds, said Davis.
“That’s perfect conditions for piping plovers,” she said.
North Brigantine Natural Area turned out many chicks this year, said Davis. But it still doesn’t approach the high numbers there in the early 2000s, she said, when 17 pairs bred there.
This summer, of four pairs there, three nested successfully and fledged nine chicks, she said.
That population is a little unusual, Davis said. They nest closely together and oversee each other’s chicks.
“In general they are territorial and don’t like sharing,” said Davis. But the North Brigantine birds seem to trust one another.
“It was communal this year,” she said.
Northern Monmouth County, which runs from Sandy Hook National Refuge to Seven Presidents Park in Long Branch, is a bright spot, generating about half of the state’s pairs and young.
In 2017, the municipality of Sea Bright “was off the charts amazing,” Davis said, with 10 pairs nesting and fledging a whopping 26 chicks, she said.
“That’s 2.6 chicks per pair. You need about one chick per pair to maintain the population, and the federal recovery goal is 1.5 per pair,” said Davis.
The birds live in a dynamic system, she said, adapting to changes on the coast. More recently, it may be more than they can handle, especially with sea-level rise.
“But living in a system that fluctuates, you can’t get yourself too wrapped up in one year’s story,” said Davis. “Still, there is no denying we are in a decline, and Cape May County in particular is a tough nut to crack.”
Many people are working on the problem, she stressed.
“There is a lot of brainpower behind it to try to keep these guys here as long as we can,” said Davis.
Davis, of Cape May Point, is a Stockton University graduate and works out of the Tuckahoe Wildlife Management Area.