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Osprey

Common Name: Osprey.

Scientific Name: Pandion Haliaetus.

What to look for?  There is a similarity to an adult bald eagle, but an Osprey does not have the eagle’s full white head or tail. Not quite the majestic look of the eagle. Osprey are brown above and white below. Overall Ospreys are whiter than most other hawks or raptors. From below, the wings of this fisherman are mostly white with a prominent dark patch at the wrists. They have a white head with a broad brown stripe through the eye. The beak is black and strongly hooked.

Where can they be found at Carillon Stonegate Pond? Look for this raptor to fly above one of the ponds during the fall morning hours. The Osprey may also be spotted roosting in one of the trees on the north side of the pond.

How big are they? The Osprey averages 22 inches in length. They weigh in at approximately 3 ½ pounds. And their wingspan is an expansive 6 feet.

What are their flight patterns? Ospreys are adept at soaring and diving but are not as maneuverable as other hawks. They fly with stiff wingbeats in a steady, rowing motion. And they have a marked kink in their wings, making an M-shape when seen from below.

How else do they behave? The Osprey is also known as the "Fish Hawk". When Ospreys hunt, they are singularly focused, diving with feet outstretched and eyes sighting straight along their talons. Ospreys search for fish by flying on steady wingbeats over relatively shallow water. After a successful strike, the Osprey pulls up from the water and flies away, carrying the fish head-forward with its feet. This sight is fascinating to observe.

What’s for dinner? Fish – live fish! Freshly caught! The Osprey is the only hawk on the continent that eats almost exclusively live fish. Their catch usually measures about 6–13 inches in length and weighs in at less than one pound.

Where do they take up residence? Not at Carillon Stonegate Ponds – only here for the fishing! Ospreys nest in a wide variety of locations across the U.S. Their habitat includes almost any expanse of shallow, fish-filled water, including rivers, lakes, reservoirs, lagoons, swamps, and marshes. Whatever the location, Once endangered in Illinois, the Osprey disappeared as a breeding bird from Illinois about 60 years ago. In the 1990s, Cook County Forest Preserves officials, following the lead of biologists in other states, began erecting Osprey nesting platforms—40-inch-wide platforms atop 50-foot-tall posts—in the preserves, hoping the Ospreys would use them to nest. It worked. The tall structures gave the Ospreys a 360-degree view of their surroundings, something scientists say the birds need when choosing a nesting spot. Today, at least a dozen Osprey pairs breed in Cook County, with several more in other nearby counties. The Illinois Department of Natural Resources is now in the fourth year of their program designed to bring more Osprey to the state to increase the number of breeding pairs.

Where do they breed and nest? Ospreys require nest sites in open surroundings for easy approach and that give them a 360-degree view. Nests are usually built on snags, treetops, or crotches between large branches and trunks, on cliffs, or human-built platforms. Osprey nests are built of sticks and lined with bark, sod, grasses, vines, and algae. The nests in a pair’s first season are relatively small—less than 2.5 feet in diameter and and around 6 inches deep. But after generations of adding to the nest year after year, Ospreys can end up with nests over 10 feet deep and 6 feet in diameter. The female lays three to four eggs, which hatch in about 40 days. The young remain in the nest for about two months. Then they take their first flights.

Where do they migrate? The Osprey that nest in northern Illinois in summer spend winters in Florida, Mexico, and South America. Some are permanent residents in southern Florida but migratory elsewhere. Migrants travel singly, not in flocks, often following coastlines, lake shores, rivers, or mountain ridges. In Illinois, the best time to see them is during spring (March) and fall (September) migration.

What is their conservation status? There is low concern. According to the North American Breeding Bird Survey, the Osprey has recovered from a pesticide-related decline in the 1950s to 1970s and has seen slight increases in populations. Partners in Flight estimates the global breeding population at 1.2 million.

Do they make any interesting sounds? The Osprey’s whistling or chirping calls are noteworthy. Here is a link to the sounds of the Osprey.

Interesting Facts About Osprey:

  • An Osprey may log more than 160,000 migration miles during its 15-to-20-year lifetime.

  • Ospreys are unusual among hawks in possessing a reversible outer toe that allows them to grasp with two toes in front and two behind (hawks typically have a single toe in the back). Barbed pads on the soles of the birds' feet help them grip slippery fish.

  • Ospreys are excellent anglers, catching a fish on at least 1 in every 4 dives. The average time they spent hunting before making a catch was about 12 minutes—something to think about next time you throw your line in the water.

  • The Osprey readily builds its nest on manmade structures, such as telephone poles, channel markers and nest platforms designed especially for it.

  • Osprey eggs do not hatch all at once. Rather, the first chick emerges up to five days before the last one. The older hatchling dominates its younger siblings and can monopolize the food brought by the parents (those of us from large families can relate to this!).

  • The name "Osprey" made its first appearance around 1460, via the Medieval Latin phrase for "bird of prey" (avis prede). Some wordsmiths trace the name even further back, to the Latin for "bone-breaker"—ossifragus.

  • The oldest known Osprey was at least 25 years old.

For more information on Osprey and sources of information used in this blog (these are the sources that I am using to learn as I blog), please visit All About Birds, Audubon Society, Chicago Botanic Gardens, Illinois Raptor Center and Friends of the Chicago River.  There is an excellent article in the Kane County Chronicle. And the Cornell Lab of Ornithology provides a wonderful source of information for anyone interested in learning more about birds.

The Carillon at Stonegate community is very fortunate to have a variety of wetland, forest and prairie environments conducive to a variety of birds and other wildlife, plants and insects. Our community and the Kane County Forest Preserve do an exceptional job in maintaining this natural environment – both for the benefit of the birds and wildlife and for our residents to enjoy.

 

Take a hike and see what you can find – and identify!

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