The South Coast Ospreys Are Back

This article first appeared in the New Bedford Standard-Times, April 22, 2018

The South Coast Ospreys Are Back

Photo: Courtesy of Mass Audubon Society

The first returning resident was seen on March 20, doing a bit of housekeeping atop his pole on the Westport River. Since then, dozens more have poured in from their wintering ground in South America, most returning to the exact same spot he or she left last September.

They’re smart birds, and probably have noticed that many manmade nesting sites in their community are brand-new, erected precisely where a former pole stood before it was blown down or sheared off its base by ice this winter.

Lots of housekeeping on the part of Gina Purtell, the director of Mass Audubon’s South Coast Sanctuaries, and a dedicated crew of assistants and volunteers, has ensured that the majestic hook-beaked, white-bellied home-comers found their homes intact, when a few months ago that was far from the case.

The same harsh conditions that felled so many trees also severely battered and bruised the ospreys’ artificial nesting sites. Twenty of the South Coast Osprey Project’s 80 poles and attached platforms on the Westport River were wiped out; a few of its ten posts on Allens Pond ended up leaners; and numerous other platforms and underpinnings were found washed up on beaches or spotted by fisherman afloat in Westport Harbor.

Four poles managed by The Lloyd Center on the Slocum and Little River also required significant repairs. “It was grueling, but we finished in the nick of time. We’ve got our four pairs back, and eggs are due any time,” said research associate Jamie Bogart.

Most of the Audubon project’s posts are erected on saltmarsh islands. The ospreys love these perches, so close to fish yet removed from the forest’s predators, chief among them the great horned owl.

The poles therefore can be lower (5-to- 10-feet tall) than those placed on the shoreline, which makes it easier to make repairs and monitor osprey families.

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But global warming may be overwhelming the marsh islands and the osprey sites that sit on them.

Sea-level rise could be making the ground less stable, said Purtell, as well as accelerating “marsh collapse,” symptoms of which include thinning grasses and calving of the islands’ edges.

Garrett Stuck, a Westport resident and avid birder, is part of a group of Audubon volunteers who every spring motor out to the saltmarsh islands to inspect the manmade nest sites before the birds arrive home. “Normally, we go out in the skiffs and shore up a few platforms here and there. But this year was wholesale destruction from the ice. Again and again we found only a broken stump” where a pole once had been.

A bad storm in January, followed by severe cold, “was like a one-two punch,” recounted Purtell.

“High tides carried large cakes of ice across the marsh islands, and the poles just snapped off.”

Purtell, who has built up a loyal network over the years, began making calls. Lowe’s “went above-and-beyond the call,” she said, freely donating sturdy posts, wood supports, fasteners, and garden fencing to cover the platform to prevent nest sticks from falling through the slats.

“When I heard about the Osprey program, I immediately thought this would be something Lowe’s would love to be involved with, to help the community as well as the surrounding wildlife,” said Paul Albernaz, a store manager for the company.

Home Depot and Kirby Paint also rose to the occasion and provided discounted items, while one volunteer donated a new tool kit.

Carpentry students at Friends Academy and environmental engineering students at Greater New Bedford Voc-Tech took on the task of assembling platforms. Volunteer water crews ventured out in skiffs and canoes to replace posts and brace the platforms on top. An osprey nest can be sizeable, requiring a large platform. As long as the nest isn’t swept away — and so many were this winter — the returning couple keeps fortifying it with sticks year after year, until some nests are three or more feet across.

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What would have happened if repairs hadn’t been made in time, and dozens of ospreys finished their long migration north to discover their nesting sites gone or too broken to inhabit?

“There would have been lots of fighting over any available sites,” noted ornithologist and Dartmouth resident Alan Poole. A leading osprey authority, Poole has been a longtime pillar for the South Coast Osprey Project, erecting and fixing hundreds of nesting sites over the years and collecting a treasure trove of data that is helping humans understand their brethren bird’s behavior better.

“Many would not have nested. Or, they would have sat around and finally made a nest. But it takes time, and it’s hard to find a good tree to hold a nest. If they don’t find the right place to nest, they don’t lay eggs.” Some might have built nests on power poles, chimneys, and piers, encroaching on human life more than is good for either species.

While an osprey couple returns to the same nest year after year, the male and female don’t winter together. “The joke is,” Poole shared, “that the only reason ospreys stay mated for life is that they winter in separate locations. One might go to Cuba, the other Argentina. The nest is the lure; they come back for the nest. It’s all about progeny.”

“By creating an artificial nesting neighborhood, we’re upping the odds. We’re making it easy for them.”

For the last few years, the Osprey Project’s local population has hovered around 90 active breeding pairs, a recent all-time high. Purtell is aware of additional pairs nesting in trees on private property and on rocks along shore, and of still others simply passing through.

Back in the 1800s and early 1900s, as many as 1000 breeding osprey pairs nested along the Northeast coast, from New York to Boston. But by 1964, the local Dartmouth/Westport population had experienced a dramatic loss, as had so many other osprey strongholds, and was down to 6 pairs, largely due to the pesticide DDT and its lethal effect of reducing calcium in the mother’s body, resulting in eggshells too thin to successfully carry forming chicks.

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In 1965, Gil and Jo Fernandez, concerned that something in the environment was drastically reducing osprey hatchlings, began putting up poles on their 100 acres beside Allens Pond. The practice had been around for a long time, ever since New England farmers first realized that if you put up a post with a wagon-wheel on top, “ospreys were on it like flies on honey,” likens Poole.

Once DDT was banned in this country in 1972, it took some years for the natural landscape to bounce back, but by the late 1970s the ospreys were increasing by 10 percent each year.

Today’s fertile population appears to be seeding nearby neighborhoods. Historically, Cape Cod has seen relatively few osprey, according to Poole, but now some 200 to 300 resident pairs nest there.

“Gil Fernandez referred to his land as an Osprey Orchard, the idea being that we are out there cultivating these birds and their nest sites, allowing them to succeed,” noted Poole.

No one is altogether sure what the area’s carrying capacity for ospreys might be. Manmade nesting sites on the east and west branches of Westport River are maxed out, as the Westport Conservation Commission only makes 80 permits available. And for some reason, nests on Allens Pond don’t produce as many young.

Nevertheless, since the ospreys clearly like the area, the general sense is that their presence is likely to continue to grow, with or without artificial “trees,” as is true throughout the country. The once-endangered species, now plentiful, stands at over 25,000 pairs in the United States, with another 8-10,000 in Canada.

Here in our local corner, Gina Purtell and her band of Audubon volunteers, closely monitor the ospreys’ seasonal comings and goings, as do hundreds of others who keep a pair of binoculars by the door.

“We’ve constructed these sites for them; we’ve become their stewards,” said Purtell. “They’re really good at taking care of themselves, but we would be negligent if we didn’t maintain the homes we have built for them.”

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Some people ask, what’s the big deal about ospreys?

There’s something important going on that we can’t see, Purtell stresses. “The osprey is at the interface of a constant exchange.” By eating lots and lots of fish, the species is turning life from the ocean into nutrients for the coastlines and saltmarshes.

Noted Garrett Stuck, “One thing you can say about the osprey is that they are a barometer of our ecosystem. We saw that back in the ’60s when DDT wiped them out.”

Poole, not surprisingly, hopes osprey numbers continue to soar indefinitely.

“By bringing these charismatic, wild and magnificent creatures into our midst, we’re increasing people’s awareness of the natural world. The fact that you are seeing out of your window a bird that just came back from the Amazon Basin means that you are more aware of the planet and the habitats that are needed to sustain this remarkable creature.”

Climate fluctuations have their effect, too. Last year, the spring season was not kind to local ospreys. Wind, cold, and prolonged downpours hit just as many females were incubating eggs or nourishing newborns, and as a result an usually high number of eggs and chicks perished.

Around Memorial Day, when Purtell and volunteers go out on the marshes to inspect this year’s chicks, they’ll hope to find two, three, even four fuzzy heads in every nest.