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Ospreys, Pandion haliaetus

Osprey perched on a log

Ospreys are distributed globally and can be found on every continent except Antarctica. They occupy a wide range of habitats, including coastal areas, lakes, rivers, and reservoirs. They are particularly associated with bodies of water that support fish populations, as fish comprise their primary food source, rarely small mammals, birds, or reptiles.

Ospreys are superb fish hunters.They are agile and powerful fliers with long, broad wings that allow them to soar effortlessly for long distances. They have several adaptations that enable them to excel in catching fish. When hunting, they soar high above the water and use their keen eyesight to spot prey from great distances. They can hover in mid-air, adjusting their position to accurately judge the depth and location of their target fish. Once they spot a fish, they dive feet-first, plunging into the water to snatch their prey with their sharp, curved talons. Trout, bass, mullet, flounder, smelt, and bullheads are common targets.

Ospreys have reversible outer toes that allow them to grasp fish with two toes in front and two behind, providing a secure grip. They also have a unique adaptation called a “talon-rotor joint” that allows them to orient the fish parallel to their body during flight, reducing aerodynamic drag.

Ospreys construct large, bulky nests typically located in tall structures, such as trees, cliffs, rocky outcrops, or man-made structures like utility poles or platforms specifically erected for their use. They prefer elevated locations near water, offering easy access to their hunting grounds. The nests are made of sticks, branches, and other plant materials. Ospreys often return to the same nest site year after year, adding more material to reinforce and expand the nest, sometimes causing their supporting trees to collapse.

Female Ospreys typically lay 2 to 4 eggs several days apart and are incubated primarily by the female, while the male provides food for both the female and the growing embryos. Incubation lasts around 5 to 6 weeks. After hatching, the chicks are initially helpless and rely on their parents for warmth and food. Both parents participate in feeding the chicks, providing them with fish brought back to the nest.

The young ospreys fledge, or leave the nest, at around 7 to 8 weeks of age. However, they continue to depend on their parents for food and guidance for several weeks or even months after fledging. During this time, they learn to hunt and refine their flying skills. As they become more proficient, they gradually gain independence and venture farther from the nest. The parents may continue to provide occasional support until the young ospreys become fully self-sufficient.

Ospreys are migratory birds, and their winter ranges can vary depending on their breeding locations. In general, they undertake long-distance migrations to warmer regions and more abundant food sources. Ospreys from North America migrate to Mexico and Central and South America, while European populations migrate to Africa. During migration, they navigate along well-established routes, often following coastlines or major water bodies.