It can be a bit of a pain fishing for a couple of hours over a favorite spot, without a single hit! In the meantime, a hovering fish hawk (=osprey) plunges to the surface, and on its first try, it emerges with a nice size fish in its claws! Yikes, that sight could make it even more frustrating! The bird is said, on average, to spend only about 12 minutes scanning the water’s surface for its next catch. Then, as it dives from a height of up to 130 feet, its fishing success rate can be as high as 74 percent!
An osprey’s vision is particularly well adapted for detecting its prey from a perch on an overhanging tree branch or while hovering high above the surface. Once it has detected a potential meal swimming near the surface (at a depth of no more than 3 feet), it dives at a speed that reportedly can reach 30 to 50 mph! As it descends, the raptor spreads out its sharp, curved claws one of which is pointed from the rear, like a person’s thumb. In addition, its footpads are equipped with spines, helping it to grasp and hold its next very fresh feast. As it flies back to its nest or perch, the bird carries the fish head forward to reduce drag.
Ospreys inhabit areas near shallow fresh and coastal waters. With the exception of Antarctica, they winter and/or breed at sites on every continent. In North America, they can be found from the Florida Bay to Canada, in the mid-west, west coast and into Alaska. From the 1940s to the ‘60s, there was a huge drop in the bird’s populations throughout many regions. From 1954 to 1968, renowned artist and ornithologist, Roger Tory Peterson, (Field Guide to Birds) observed a decrease in the osprey’s population within 10 miles of his Old Lyme, Connecticut home (located along the Connecticut River). During that time, he noted the loss of some 150 nests. In 1968, the size of a New York State colony had decreased “from 300 nesting pairs to 30 nests in 1968.”
Much of the blame for the decline was attributed to the pesticide DDT. Exposed to the chemical, the osprey’s eggs were so brittle that they were easily crushed, simply by the weight of the brooding parent. However, following the 1972 banning of the pesticide, fish hawks began their long recovery. Even along the Great Lakes, where during the late ‘60s, there were very few identified nests, ospreys have made a comeback. In 2018, the Connecticut Audubon Society’s Osprey Nation stewards reported “416 active nests that fledged 725 Osprey young.”
Florida’s osprey population remains year-round in the state. Those residing in the northeastern states, migrate south for the winter, following the same route seasonally. Their cold-weather grounds include Florida, Caribbean Islands and certain sites in South America. Some of the more northerly western birds, winter over in Central America.
A young female osprey named Penelope, the resident of Martha’s Vineyard, Massachusetts, was fitted with a GPS transmitter and released in the late summer of 2008. She managed to reach French Guiana, a distance of 2,700 miles, in just 13 days. Traveling by herself at night, she stopped to roost and dine on fish at a couple of Connecticut ponds (near the Rhode Island border). She then headed across Gardner’s Island arriving along the Maryland coast, just north of Chincoteague Bay. She also managed to rest and recuperate at the Bahamas’ Acklins Island before resuming her southward trek. Flying across Cuba and the Caribbean Sea, she finally made landfall in Venezuela before flying to her final destination, east of that nation.
Typical of young ospreys on their maiden winter migration, Penelope remained in South America for 18 months, before flying back to her Massachusetts home. Adult males are usually the first to leave their winter residence, arriving at their former nest before the female. A long term bond between pairs is common.
Ospreys refurbish their nest yearly. Both of them carry in fresh materials (small branches, seaweed, marsh grasses and occasionally plastic bags or other soft materials left behind by human occupants). Females tend to do most of the nest’s rearranging. With the project completed, the males frequently deliver food to their companion.
Egg laying in the migratory group generally begins in April and May. Non-migratory ospreys breed during the winter and spring. On average, a female lays 3 eggs which hatch in about a month. These birds of prey build their nests, near water, on dead trees, channel markers and artificial nest platforms (and other convenient structures). It is generally believed that construction of platforms has aided recovery of the bird’s population.
Ospreys dependence on local fish and their sensitivity to contaminants have made them an important “indicator species for monitoring the long- term health of rivers, bays and estuaries.” As successful aerial fishermen, they are a delight to watch as they plunge into the water and carry off their catch. Connecticut Audubon, Cape Henlopen State Park (Delaware) and others maintain osprey cams that allow the viewer to easily watch the birds’ activities from a computer. Children and adults will enjoy observing their antics.
Connecticut Audubon Osprey cam https://www.ctaudubon.org/osprey-nation-osprey-cam/
Cape Henlopen State Park Osprey cam DE https://www.friendsofcapehenlopen.org/ospreycam.html