A recent visit to the Oak Bluffs home of Dick Jennings found him worrying over the safety of a friend traveling in the Caribbean. Although he’s never met Long Island Bob, the friend in question, he’s developed an attachment and has justifiable concern for him.
Luckily, on his computer, he’s able to track Bob’s precise movements as he heads farther south. That’s because Long Island Bob is one of five ospreys fitted with tracking devices that Mr. Jennings has been following. Bob, two birds from the Vineyard, one from Nantucket, and one from Delaware are the subjects of an ongoing study by Richard O. “Rob” Bierregaard, a raptor expert and research professor for the University of North Carolina at Charlotte.
Now, a good two months since the ospreys left for warmer climes, Mr. Jennings checks in every few days to make sure they have made it to their respective South American winter homes. Three are safe, one was lost in Curacao. Bob, who is headed for his regular roosting place in Venezuela, is currently in the Dominican Republic. Treacherous turf for an osprey since a number of the birds tracked by Mr. Jennings and Mr. Bierregaard have been shot while enjoying the easy pickings found at fish farms there and elsewhere.
An amateur naturalist, Mr. Jennings moved to the Vineyard in 1990 after a career as a manager for the plumbers and steamfitters union in Orange and Ulster County, N.Y. Not one for whom retirement meant slowing down and enjoying his lifelong love of fishing, Mr. Jennings took on a full-time job with the Trustees of Reservations two years after relocating. Due to a lifelong interest in raptors, Mr. Jennings became aware of the work of Mr. Bierregaard and checked in online regularly to see when particular birds would be returning. An inquiry about the progress of one of the ospreys led to a meeting with Mr. Bierregaard, which led to a longterm relationship. On his website, Mr. Bierregaard refers to Mr. Jennings as his “right hand man.”
Mr. Bierregaard began studying the Vineyard ospreys in 1969 when there were only two nesting pairs. The use of DDT had nearly wiped out the species at one time. This past summer 78 pairs summered on the Vineyard and successfully fledged 112 offspring.
According to Mr. Jennings, the osprey’s lifestyle is unique among birds — in many ways. Although they mate for life, the entire family splits up once they leave their summer nests. The females leave in August shortly after the chicks have fledged. About four or five weeks later, the fledglings depart. The males are the last to leave. The fledglings set off with no particular destination in mind. Mr. Jennings notes that the tracking devices have disproven the theory that young ospreys settle in after a predestined 35 days on the fly. The birds all eventually wind up in South America but at different times and at points all over the map. A mated couple will not reunite until they return to their established nest in the spring.
“What happens in Rio, stays in Rio,” jokes Mr. Jennings.
Mr. Jennings believes that a lack of adequate nest sites accounted for the delayed reintroduction of ospreys on the Vineyard. Although the Island outlawed DDT in 1958, more than 10 years before the drug was banned nationwide, it took almost twice as long as elsewhere — about 18 years — for re-population to occur.
Mr. Jennings explains that naturalist Gus Ben David is largely responsible for addressing the situation. In 1970, the dedicated naturalist and former director of Felix Neck Wildlife Sanctuary started putting up poles, which Mr. Jennings now helps him to erect and maintain. Ospreys often build nests in tupelo trees and pitch pines, both of which grow here but, as Mr. Jennings notes, “There are not enough that are substantial enough or strong enough for a nest that weighs up to a ton.”
Currently there are 170 potential nest sites, thanks in large part to Mr. Ben David’s work. In the spring, Mr. Jennings is responsible for checking every one of the nests to determine if they’re active. He codifies the information by town and logs his collected data onto his computer. Mr. Bierregaard visits in May to finish up the survey, then returns at the end of the summer to tag the juvenile birds. In between Mr. Jennings is responsible for tracking the birds’ progress. “I follow up on how many birds fledge and how many nests fail,” he says.
Mr. Jennings estimates that his volunteer work is about equivalent to another full-time job. But he doesn’t mind the long summer hours at all. “It’s very rewarding,” he says, “I didn’t think I’d ever wind up with this kind of opportunity. I’ve learned so much from Rob and Gus Ben David. Gus is the key to the whole return of the ospreys to the Vineyard. He’s done more for wildlife and education than anyone I can think of.”
Next year, if funding is available, the research focus will be shifting a little. Rather than tagging young birds at the end of the summer, Mr. Bierregaard and Mr. Jennings will be fitting adults with tracking devices in the spring. They are trying to determine why the population growth has stalled. Mr. Jennings notes that the current numbers are at about 50 percent of what they once were.
The two men hope to acquire two very sophisticated new tracking devices that communicate with cell phone towers. These will be used in conjunction with two high-tech motion-detection cameras set up at feeding sites. The researchers will compare the activity of two pairs of birds — one that has historically been successful in producing offspring and one that hasn’t produced at all. The new equipment will enable the men to determine where the males — the sole food providers — are hunting, how long they are gone from the nest, and exactly what they bring back. Depletion of fish stocks may be part of the problem.
The new devices will also allow the men to keep tabs on the birds on a minute-by-minute basis. The units currently in use operate on satellites and only deliver data once every three days. Mr. Jennings is hopeful that they will have funding in place by the spring.
“Rob and I have been extremely fortunate to be able to conduct this ongoing research due to the generosity of some of the residents here on the Vineyard,” he said. “If we are fortunate enough to raise the funds to purchase the units, we will recycle them and use them on other ospreys here on the Vineyard.”
Mr. Jennings has been active in warning people about a very real threat to ospreys on the Vineyard. Birds often pick up discarded fishing line to help bind their nests. Mr. Jennings and Mr. Bierregaard have discovered ospreys strangled or hanging from their nests.
Fishing line endangers other forms of wildlife as well, Mr. Jennings pointed out. “There are spent line boxes everywhere,” he said, “Put it in one of those boxes or stuff it in your pocket. How hard can it be.”
During a follow-up interview with Mr. Jennings, he reported that Long Island Bob had made it safely to his winter grounds in Venezuela. It is with a great sense of relief that he relays this information. “You get a personal attachment to these birds,” he says, “You’re handling them.”
He’ll check in on the four surviving ospreys occasionally all winter and then, in March, the anxious waiting process begins again as the birds head back to their summer homes. “We’ll have our talons crossed,” he says. “Our toes crossed. Everything.”
Correction: An earlier version of this story misidentified Richard O. “Rob” Bierregaard as Dick Jennings in the photos.