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In the scenic surroundings of New York’s Hudson Valley, the osprey population is making headlines with its novel nesting choice. These formidable birds are setting up homes atop the Bear Mountain Bridge, a notable suspension bridge stretching 2,255 feet and located approximately 50 miles north of Manhattan. This isn’t a first for the species at this location.
“Two years ago, we observed that ospreys began to build nests on the top of the bridge tower,” explains Craig Gardner, the maintenance manager for the New York State Bridge Authority. “While we attempted to deter them from nesting there, the situation escalated last year when we discovered they had laid eggs before we could take action.”
An osprey rests in its nest atop New York’s Bear Mountain Bridge in May 2024. CREDIT: New York State Bridge Authority.
Ospreys are renowned for their exceptional fishing abilities, swooping down to catch fish from bodies of water and returning to their nests with their prey. As one of the most widely distributed raptor species, ospreys are typically found near water sources, where they can access ample food. Ongoing conservation initiatives in the Hudson River and adjacent areas have significantly aided the resurgence of local wildlife, including bald eagles and peregrine falcons, alongside the fish populations these birds depend on.
“Unlike peregrine falcons, which lay their eggs directly on the stone, ospreys actively construct nests,” Gardner elaborates. “We provide stones in boxes for the falcons as they are adaptable in their nesting methods.”
In 2024, two chicks hatched in the Bear Mountain Bridge osprey nest. CREDIT: New York State Bridge Authority.
Gardner notes that the chicks from last year’s nesting season thrived and remained within the nest for much of the year. While the successful nesting indicates a positive ecological recovery for the Hudson, it also raises concerns regarding the safety of the approximately 20,000 vehicles that traverse the Bear Mountain Bridge daily. Given that the nest is situated about 250 feet above the roadway, there is a risk of falling debris, including sticks and fish, endangering motorists below. The New York State Bridge Authority typically encourages birds to nest on lower spans away from the traffic, but the ospreys seem to prefer a lofty perch with beautiful views.
The proposed solution involves the installation of human-engineered steel nesting boxes tailored for ospreys. Instead of dismantling existing nests, workers are creating modular steel boxes that provide a safer environment for the birds and contain any potential falling debris.
Five crew members installed the steel nesting boxes in March. CREDIT: New York State Bridge Authority.
“We engineered these nesting boxes to be modular for easy transportation,” states Gardner. “Using a motorized platform, one team member ascended to the top of the tower to assemble the boxes on-site. The design accommodates the wide spacing required for the large sticks used by the birds, supplemented with mesh for safety.”
In total, the installation involved transporting approximately 500 pounds of steel to a height of 350 feet.
The osprey returned promptly to refurbish their nest following the crew’s installation work. CREDIT: New York State Bridge Authority.
“We brought the components up in sections and assembled them atop the tower,” Gardner explains. “The birds wasted no time in coming back to rearrange their sticks and settle into their home.”
As of now, there is no update on the current number of eggs in the nest, but the Bridge Authority plans to provide further information as the nesting season progresses.
Source
www.popsci.com