The song of a red-winged blackbird, the echoing choirs of spring peepers, and the thundering gobble of a wild turkey are just some of the welcoming sounds of spring. But of the cacophony of bird calls, nothing is music to my ears more than the high-pitched chirping call of an osprey.
At press time there have been no sightings of the predatory birds on the North Fork, according to Debbie O’Kane, president of the North Fork Audubon Society, though ospreys usually make their first appearance around St. Patrick’s Day.
Feeding almost exclusively on fish, ospreys are commonly referred to as fish hawks or sea hawks. Their very specific diet requires that they live within close proximity to open waters such as rivers, lakes, bays or the ocean. With a wingspan of more than five feet, an osprey will soar high above the water, using its keen eyesight to locate prey that is swimming close to the water’s surface. Once prey is located, it hovers above, waiting for an opportune time to strike. When the time is right, it will tuck its wings and begin a speedy descent toward the water. Moments before impact, the osprey will pull its legs forward and crash feet first into the water. Amazingly, the osprey never takes its eyes off its target, even looking between its legs as it hits the water.
This fishing method is much different than the technique used by another fish hunting raptor, the bald eagle. When an eagle spots a fish, it will do a fly-by, snatching the fish from the water, getting nothing more than its talons wet. An osprey, on the other hand, becomes completely soaked as it dives up to three feet into the water to catch a fish. Specialized wing joints allow them to bend their wings in such a way to allow for a vertical takeoff from the water. Once airborne, a couple midair shakes will shed any excess water that is trapped within the feathers (which are oilier than other species of hawks).
Sharper than a top-of-the-line fishhook, the osprey has a razor-like talon at the end of each of its eight toes. The typical orientation of a hawk’s toes is three facing forward and one facing back on each foot. The positioning of an osprey’s toes is unique. For improved efficiency, they are capable of rotating the outer toe of each foot to the back, letting them get a better hold on slippery fish. The soles of their feet are lined with many small “spikes” that act like a barb on a fishhook, giving the osprey additional gripping power. For improved efficiency, an osprey will carry its prey head first, making it more aerodynamic as it flies to a perch with its meal.
Not only are ospreys superior anglers, they are also quite the world travelers, with our local population wintering in the rain forests of Central and South America. With the potential of having a lifespan of 15 to 20 years, it is very possible for an osprey to travel over 150,000 miles in its lifetime.
Although ospreys mate for life, they spend the winter apart, reuniting at the nest site each spring. The male returns (mid-March) prior to the female and will begin to repair any damage that might have occurred to the nest during their absence. Nests are constructed in wide-open locations, close to water, and high enough to protect chicks from ground predators. On Long Island, in addition to man-made nest platforms, I have observed nests built in trees, on telephone poles, radio towers, channel markers and even on top of a duck blind. With each passing year, the pair builds the nest larger. If the base structure is strong enough, the nest has the potential to reach sizes of ten to thirteen feet wide by three to six feet deep.
When the female returns, the male begins an elaborate “love dance” in the way of aerial displays in hopes of enticing her to breed. After mating, she will lay a clutch of two to three eggs, over a period of several days. She will remain in the nest to incubate the eggs for 34 to 40 days and an additional week to brood the hatchlings. During this time, the male is extremely busy, continuously hunting to feed his growing family, while also remaining vigilant against any threats to the nest. At around six weeks of age, the female will leave the nest to assist him in providing nourishment for his new family. Young osprey will leave the nest around eight weeks, but will remain close for several weeks before starting their first migration south.
During the 1950’s to 1970’s, osprey populations dramatically declined due to an insecticide known as DDT. Used to control mosquitoes, DDT initially entered the environment low on the food chain. As DDT contaminated organisms were consumed, the chemical was passed onto the predator and stored within their fatty tissue (a process known as bioaccumulation). As the toxin moved through the food web, the concentration became greater in top predators (a process known as biomagnification). As an apex predator, osprey were absorbing very high levels of DDT. The outcome of this poisoning was a thinning of their eggshells, which would cause them to be crushed by the female as she incubated them. In 1972, the EPA banned the use of DDT, which resulted in a resurgence of this majestic bird of prey.
As a fisherman and marine biologist, hearing that distinctive call is not only exciting because it marks the return of spring, it is also a sign that our local waterways are once again about to come alive with marine life.
To see a live feed of an osprey nest, check out the North Fork Osprey Cam at ospreyzone.com
Places to see osprey on the North Fork:
Peconic Riverfront Park (behind Main Street in Riverhead)