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[Note Guidelines] Photographer's Note |
Food Habits:
Ospreys are unusual among raptors for being piscivores. Their diet consists almost exclusively of fish (≥99% of prey items). They are generally opportunistic, and will eat whatever fish species are accessible to them either in shallow waters, or near the surface of deeper waters. Studies in North America have documented more than 80 different prey species of ospreys. However, 2 or 3 common species may dominate the diet of local ospreys in a given area. (Poole, 1989; Poole, Bierregaard, and Martell, 2002)
Ospreys hunt for fish on the wing (less often from a perch), flapping and gliding 10 to 40 meters above the water. When an osprey spots a fish, it hovers briefly, then dives toward the surface of the water. Just before hitting the water, the osprey swings its legs forward and bends its wings back, plunging feet-first into the water. The osprey uses strong, almost horizontal wing beats to lift itself and its prey from the water. Once airborne, the osprey rearranges the fish in its feet, carrying it with one foot in front of the other so that the fish is facing forward. This position presumably makes the fish more aerodynamic, and easier to carry. The osprey then takes the fish to a perch, often near the nest, to eat. Osprey generally eat fish beginning with the head and working toward the tail. A male who is also providing food for a mate and offspring during the breeding season will typically consume at least part of the fish before delivering the remainder to the female. Ospreys do not cache fish. If a fish is larger than an osprey (and his mate and offspring if breeding) can consume, the fish is discarded, carried around with the osprey, or left in the nest. Ospreys do not generally need to drink water. Fish flesh supplies sufficient amounts of water to meet their requirements. (Poole, 1989; Poole, 1994; Poole, Bierregaard, and Martell, 2002)
Ospreys catch fish on 24 to 74% of their dives. This success rate is affected by individual ability, weather and tide. Some studies have shown that ospreys are most successful hunting at midtide and when the weather is calm. (Poole, Bierregaard, and Martell, 2002)
Though the vast majority of osprey prey items are live fish, ospreys have been observed to eat other foods on occasion. These include birds, snakes, voles, squirrels, muskrats (Ondatra zibethicus), salamanders, conchs, and even a small alligator (Alligator mississippiensis). Reports of ospreys feeding on carrion are rare. However, they have been observed eating dead white-tailed deer (Odocoileus virginianus) and opossum (Didelphis virginiana). (Poole, Bierregaard, and Martell, 2002
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