Text by Peter Vankevich
Photos by Hal Broadfoot and Peter Vankevich
Time for a much-needed spectacular avian comeback story.
The Osprey (Pandion haliaetus) is the only bird of prey in North America that will hover in the air beating its wings before plunging, sometimes at more than 30 mph, feet-first into the water to snag surface-swimming fish.
It is not unusual to see a flying Osprey carrying a fish, its preferred food, in its sharp talons, delivering it to the offspring or mate or to a favorite perch to enjoy lunch.
On Ocracoke, one can spot Ospreys during the spring and fall migrations as well as young individuals dispersing from the nesting grounds in late summer.
These are large birds of prey with wingspans of nearly six feet and body lengths of 24 inches. When they are perched, note the brown back, dark crown and white head and a dark eye line. In flight, they display a white underwing and a
distinctive bend at the “wrists” so that the wingtips angle slightly backwards, creating a signature boomerang silhouette.
Monogamous, Ospreys often mate with the same partner for life and begin nesting at three years of age. Adults often return each year to nest at the same site where they were born. The large nest, called an eyrie, is made of sticks, reeds and mud.
When Ospreys return the following season, they renovate it with additional materials. Over many years, nests sometimes grow so large and heavy they will collapse.
Typically, the female lays two to three eggs with an incubation period of 30 to 40 days. Once hatched, the female broods the nestlings for 10 days while the male provides food. Fledglings leave the nest after about eight weeks.
During breeding season, Ospreys are quite vocal with a repertory of high-pitched, whistling calls.
The largest Osprey population in the world is found in the Chesapeake Bay region with estimates of up to 12,000 pairs.
Folklore tradition, as noted in James Michener’s 1978 epic novel “Chesapeake,” holds that Ospreys return on St. Patrick’s Day. More recent years have them returning as early as February.
These raptors are truly cosmopolitan, being present on every continent except Antarctica. In North America, Ospreys are migratory and breed throughout much of the continent in a variety of aquatic habitats, such as rivers, lakes, boreal ponds and salt marshes.
In the north, they breed from Newfoundland west to Alaska and south to the Gulf Coast and Florida. In North Carolina, they nest mostly along eastern waterways, but are seen across the state during migration. Their range includes the Gulf States, Caribbean and Central and South America south to Argentina.
When to see: Early March into late spring, August into late fall, rare in winter.
Where: In flight anywhere over the island and surrounding waters, perches throughout the island on trees and structures including in the village.
Listen: The Macaulay Library at the Cornell Lab of Ornithology has a variety of Osprey recordings. Click here.
Try to stump a birder with this question: What do an Osprey and a Barn Swallow have in common? Both have increasingly relied on human-created structures rather than natural areas to build their nests.
Whereas Ospreys historically have selected large trees, rocky cliffs, or mammal–free islands to nest, in the last 70 years or so they have used artificial sites for their nests such as channel markers, bridges, tops of utility poles and communications towers. But the most common sites these days are purpose-built nesting platforms.
Some electric utility companies have installed these nesting platforms for Ospreys to use in lieu of utility infrastructure.
According to several studies, up to 90% of Osprey nests these days are on human-created structures.
One such study in the Chesapeake region found that use of trees for nesting had declined from 31.7% to 7.2% over a 23-year period and the use of human-created sites has been one of the most important factors contributing to the Osprey population expansion.
On the way to the Outer Banks crossing the Wright Memorial Bridge there are several Osprey nesting platforms alongside the powerlines in the Pamlico Sound. In Frisco alongside NC 12, there is an eyrie on a communications tower.
While there are no nesting platforms in Ocracoke there have been a couple in the past. Not surprisingly, these structures fell to powerful storms striking the island.
There are also no Osprey nest platforms in the Cape Hatteras and Cape Lookout National Seashores. According to spokesperson Mike Barber, the National Park Service management policies state that whenever possible natural processes are to be relied on to maintain populations of native animals and plants.
For those interested in attracting these birds to their area, placing a “bird nesting pole” in water, requires a general permit from the NC Department of Environmental Quality Coastal Management Division and there are restrictions as to where and how they may be placed. As an example, the regulations say that the platform cannot exceed 3’x3’ and not have sides and “may” be located up to a maximum of 400’ from the mean high or normal water line, whichever is applicable.
To obtain more information on placing a nest platform in water, contact a coastal field representative in the Washington, N.C., office, 252-946-6481.
Rivalries in the avian world akin to, say, Duke and UNC Chapel Hill basketball, would be Bald Eagles vs. Ospreys. The two often tussle over nesting sites and fish. Eagles sometimes force Ospreys to release their catches with Eagles grabbing those released fishes in mid-air.
A healthy and lucky Osprey may live 20 years or more. That was not always the case.
Ospreys and several other species began experiencing nesting failures when DDT, a synthetic pesticide used to control mosquito populations, was made available for public sale in the United States in 1945.
As early as the 1950s, famed naturalist Roger Tory Peterson in the 1950s suspected that DDT was responsible for Osprey nesting failures in coastal Connecticut.
The dangers were brought to light in the 1962 best-seller, “Silent Spring,” by Rachel Carson, which spotlighted the adverse effects on the environment caused by the indiscriminate use of pesticides.
The contaminants caused eggshell thinning and embryonic deformities, drastically reducing the nesting success of Ospreys and other species.
A ban was put in place in 1972 and as the chemicals were removed from the environment, Osprey and other species including Brown Pelicans and Peregrine Falcons, began a comeback.
Around this time, for about 15 years, there were no records in North Carolina of successful nesting, but beginning in the 1980s, Ospreys began a remarkable recovery and are no longer on the endangered species list.
Chris Turner, a coastal regional wildlife biologist for the NC Wildlife Resources Commission said that there have not been any formal surveys of Osprey in the state but said current nesting numbers would certainly be in the thousands.