TIRELESS TRAVELLER - FISH HUNTER - POND ROBBER - ACE AVIATOR
General - FISH HUNTER
- The Osprey is a unique bird that is unmistakable when seen at close range. It is the only species in its family, and it is found worldwide. Its breast and belly are mostly white, with some dark streaks. The white extends out the wings, but the primaries, secondaries, and tail feathers are mottled black-and-white. The back is mostly black or dark brown. The head is distinctive with a white crest, a face bisected by a dark eye-stripe, and yellow eyes. While there is much variation, the female tends to have a streakier breast than the male.
- The Osprey's talons are uniquely adapted for catching and carrying fish: their surfaces are rough, and their toes can be held with three forward and one back, or with two forward and two back, an arrangement seen in owls but not in other diurnal raptors. In flight, they are most often confused with gulls because of their long wings, which are bent at the wrist. The talons are very similar However Ospreys have a bounce to their flight that gulls lack.
Habitat - PRECISE STRIKER
- Ospreys live near rivers, estuaries, salt marshes, lakes, reservoirs, and other large bodies of water. They they prefer water surrounded by forested habitat. They can be found near fresh or salt water, as long as the water can sustain medium-sized fish.
- Ospreys hover over the water, plunging feet first when they spot prey. They fly with slow wing-beats - a bounce- interspersed with glides. Ospreys form pair bonds through aerial flight displays and courtship feeding. The vast majority of the Osprey's diet is fish, typically 5-16 inches in size. Only occasionally, when fish aren't available, will the Osprey eat small mammals, birds, or reptiles.
- The Osprey is highly specialized for eating fish and does not stray from this diet unless necessary. When it catches a fish, the Osprey usually flies with it held headfirst.
- The female typically lays 3 eggs, although clutch sizes between 2 and 4 eggs are normal. Both members of the pair incubate the eggs for 38-43 days. After the young hatch, the female stays with them, and the male brings food. Once the young can be left alone, both parents provide food. The young do not fledge until they are 44-59 days old.
Builder - ENGINEER EXTRAORDINAIRE
- Osprey nests can be huge - both deep and large in diameter. They require nest sites in open surroundings for easy approach, with a wide, sturdy or slippery base and safety from ground predators (such as raccoons). Nests are usually built in treetops, or crotches between large branches and trunks; on cliffs or human-built platforms. Usually the male finds the site before the female arrives from their visits to Florida, the Caribean, Central or South America - a long way from the Bay.
- Nesting Ospreys build large nests near water, on top of dead trees or artificial structures that are similar to dead trees, such as utility or nesting poles. Nests are made of branches, sticks, and twigs, lined with smaller twigs, grasses, bark, moss, fish bones, and other material. They will reuse nests year after year and continue to add sticks each year, ending up with a huge nest. Nests may be more than seven feet across and over five feet deep.
Flyer - ACE AVIATOR
- Adept at soaring and diving but not as maneuverable as other hawks, Ospreys keep to open areas, flying with stiff wingbeats in a steady, rowing motion. Primarily solitary birds, they usually roost alone or in small winter flocks of six to ten.
- Nesting ospreys defend only the immediate area around their nest rather than a larger territory; they vigorously chase other ospreys that encroach on their nesting areas. In breeding season, males perform an aerial "sky-dance," sometimes called "fish-flight." With dangling legs, often clasping a fish or nesting material in his talons, the male alternates periods of hovering with slow, shallow swoops as high as 600 feet or more above the nest site. Sustaining this display for 10 minutes or more, he utters repeated screaming calls while gradually descending in an undulating fashion to the nest.
- Ospreys perform a tactical hover-plunge manuver when hunting. Ospreys have great vision and can spot fish from over 100ft. When they dive, they close their third eyelid which act like water goggles. Their attack angle is almost always 45 degrees but sometimes vertical. They can almost disappear then reappear with the fish. Shake and fly. At times, they also skim the water surface for their prey.
- When it comes time to mate, males perform a sky dance but courtship is focused on food and the nest. The male grabs a stick or a fish and delivers it to the female, swooping in from high above the nest to show his flying prowess and ability to ward off other males from the nest.
Fun Facts
- Young ospreys hatch in the spring and travel south in mid-late August. They spend their first adult year in their winter home.
- After the young fledge, osprey moms are the first to leave the nest - to eat by herself and build up for her solo trip south. Osprey males teach a little flying and feed the juveniles.
- Osprey iris turns from red in nestlings to orange-yellow in juveniles and yellow in adults.
- One-quarter of all the ospreys in the USA nest in the Chesapeake Bay.
- Females are heavier and have bigger wingspan, and are darker than males. They also have a more defined necklace. Male bodies appear slimmer with narrower wings when in flight.
- Osprey mate for life but do not migrate together. Over their 25-30 year life span they may fly 160,000 miles – separately from one another. When they migrate, they travel up to 150 miles per day.
- Osprey have opposable toes and barbed footpads to hold fish. The catch grabbed is always carried head first for aerodynamics. We have yet to see how they always position the catch that way. Do they watch the fish swim or adjust mid-flight?
- “Osprey” may have come from one or two Latin terms – “avis prede”, or bird or prey or “ossifragus”, the bone-breaker.
Prehistoric Survivor
- Osprey have been fishing for a long time (50 Million years!). Fossil remains (only a few claws) from the Eocene epoch (56-34 Million yrs. ago) belonging to some paleo-osprey have been found. Scientists have authenticated remains of osprey (wing bones), dating back to the mid-Miocene (11M yrs. Ago). The cosmopolitan birds you are watching live have ancestors that lived with the early elephants, rhinos, bats, whales, and horses. This was way back when Antarctica and Australia were separating changing ocean circulation and atmospheric patterns - and temperature. There was a global cooling event that ended the Eocene epoch.
- Interesting for Bay residents, the cooling was caused by a either a metallic asteroid, or an icy comet impacting the mouth of the Bay at 37 miles per second 35.5Million years ago. It punched a deep hole, and completely vaporized. We just discovered it in 1983 - the crater is 24 miles across, 53 miles in diameter and nearly a mile deep.
- The long lasting dent in the earth shaped the course of rivers and the location of our Bay. The immediate ejection of millions of tons of water, sediment and rocks into the atmosphere for hundreds of miles along the east coast may have caused global cooling by blocking out sunlight for years.