NEWBURYPORT — New data from Mass Audubon shows that in 2019, the state saw its highest number of piping plovers in a decade.
And with the number somewhat down this year on Plum Island, Parker River National Wildlife Refuge biologists believe COVID-19 — which kept many people in Southern states off beaches and in quarantine — may have affected where some of the birds built their nests.
This week, Mass Audubon announced that last year, its Coastal Waterbird Program, which has monitored and supported vulnerable shorebird species including piping plovers for 35 years, protected 226 pairs of piping plovers. That number is 30% of the state’s population and roughly 12.5% of the Atlantic Coast population, estimated at 1,800 pairs.
Piping plovers are small, roundish, sandy-colored shorebirds named for their repetitive piping call. Because Atlantic Coast plovers lay eggs directly on sandy beaches, they are threatened by coastal storms, rising sea levels, predators such as coyotes and crows, and intrusion on their habitats by humans and their pets.
Piping plovers are listed as “threatened” on both federal and state wildlife protection registers. And according to recently released U.S. Fish and Wildlife Service statistics for 2019, the protected species rose to 755 pairs, up from 688 in 2018. Reproductive success, which is defined by the number of birds reaching the flight stage, also rose more than 11% since 2018.
The Coastal Waterbird Program monitors 177 sites from Plum Island to the South Coast, virtually the entire Massachusetts coastline.
Plovers at sites protected by the program produced a record 1.5 fledglings per pair compared to 1.1 per pair in 2018, according to the Mass Audubon website. Additionally, chicks’ survival rate was 30% greater in 2019.
Nancy Pau, a wildlife biologist at the refuge, said that in 2019 there were about 50 pairs of plovers nesting on the six miles of Plum Island beach monitored by the refuge between Lot 1 and Sandy Point. She said that number was “unheard of.”
For this season, which started in April and will probably run through late August, Pau said there have only been about 28 pairs of piping plovers on Parker River beaches. The dip in numbers, she said, could be from a variety of factors, including bad weather this winter in the Caribbean, from which the birds migrate.
But another factor, Pau said, could be the shift in human beach activity due to COVID-19. With residents of some Southern states quarantining in March and spending less time on the beach, the birds could have settled in newly unoccupied areas.
“There’s the possibility that because there were less people on the beaches, the plovers might have moved to other areas that were more suitable to them,” Pau said. “When the plovers are looking for nesting habitats, they look for disturbances. If they are getting disturbed a lot of the time, they will move somewhere else.”
Pau said the refuge’s piping plovers started hatching last week and there are many chicks on the beach right now. The length of their stay depends on the birds’ success rate with nesting — if they fail, plovers usually make a new nest and may stick around through the end of summer.
Kiah Walker, a biological technician for Parker River, said while the refuge’s birds are nesting “a little late” and their population is down, it will be interesting to see the numbers in comparison with the rest of the state.
“They might have shifted around. Just because they’re not here doesn’t mean the numbers have gone down elsewhere,” Walker said. “It would make sense if they’re not being disturbed in other places, they might spread out a little more. They’ve really packed themselves into Parker River in the past.”
Pau also noted that the effects of increased storm activity on local beaches may also have positively affected the area in terms of its suitability for piping plovers, which could account for some of the higher numbers in recent years.
“The bigger storms we’ve had are actually changing our beach much more frequently,” Pau said. “Beaches get overwashed, waves will blow out dune areas, and that reshaping of the beach is what creates the habitat that plovers really love. Because we are able to allow that natural process to occur, it’s creating a high-quality habitat that can support more birds.”
To learn more about Mass Audubon’s Coastal Waterbird Program and the 2019 results, visit massaudubon.org/cwp.