In 2009, the Warren County Conservation Board teamed with the Iowa Department of Natural Resources to establish nesting osprey in Warren County.
Young osprey are borrowed from nests in Wisconsin & Minnesota and brought to Iowa. They are hacked out, an ancient falconry technique of slowly releasing young birds back to the wild from a secure tower structure. They are provided with food as they learn how to fly and become proficient hunters.
Osprey are neotropical migrants, spending winters in South America. They are slow to mature and will not start nesting until they are 3 or 4 years old. Nesting structures have been installed at the Annett Nature Center and Lake Ahquabi, ready for the return of released birds, or, perhaps, a migrating osprey that sees the structures and chooses to stay and nest.
In Iowa, approximately ten nesting pairs of osprey have resulted from in-state releases that began in 1997. Hopefully, the Annett Nature Center will become a nest location as its chicks mature. Chicks will arrive at the Annett Nature Center in mid-July and start flying free in mid-August. They will leave for South America by late September. In a few years, we hope to see adult ospreys at the Annett Nature Center raising their own young.
Ospreys are spectacular birds to watch, particularly when they are feeding. Hovering high above a lake, river, or pond, these large white and dark-brown birds search for fish cruising near the surface. Spotting one, they quickly fold their wings and dive, hitting the water talons first.
Osprey once nested throughout the U.S., building large stick nests near rivers and lakes. According to tribal elders of the Omaha nation, accounts of Osprey nesting along Iowa waterways are included in their oral traditional stories. However, no successful osprey nesting had been documented in Iowa since European settlement.
Osprey population plummeted in the 1950s due to the use of DDT. After the 1972 ban on DDT, populations have shown a gradual increase. This has spurred Iowa and many other states to begin reintroduction programs to expand the range of the Osprey.
Ospreys are well equipped to capture fish, their favorite prey. Strong fliers, they can cruise at 25 miles per hour. Their vision is 5 times greater than human sight. They can easily spot a fish underwater from a height of 100 feet.
While diving for prey, an osprey enters the water talons first at about 50 mph. They are the only raptors with closing nose flaps, so they can completely submerge themselves while fishing. They can catch a fish up to three feet underwater. Osprey are successful about one in three attempts.
Their pale blue toes are tipped with needle-sharp talons that act as fishhooks. They are able to swivel the outside toe, so they can turn the fish once caught, into a headfirst position to make themselves as aerodynamic as possible.
Osprey have double-jointed wings that help them dive and lift vertically out of the water.
Osprey, Pandion haliaetus, commonly called fish hawks or fish eagles, are neither a hawk nor eagle. They are classified near the kite family. Large, narrow-winged raptors, osprey weigh between 2.5 and 4.5 pounds. They have a white belly and a dark carpal patch on the underside of each wing. Their wings span six feet with four finger feathers at the tips, giving them a very distinctive appearance.
The feathers on top are a dark brown. The light stomach camouflages them from their prey, while the dark top color hides them from owls that might attack from above. To camouflage its head, an osprey has dark spots on top, and a dark mask through its eye area. This may also reduce sun glare, like the black grease used under the eyes of athletes.
An osprey’s call is a piercing, chirping cheep-cheep or yewk-yewk. When alarmed, osprey make a sharp frenzied cheereek!