From one hundred feet in the air, the hovering angler folded its wings, silently slipping from the sky.  Suddenly a four-foot portion of the lake exploded into spectacular plumes of prisomed droplets.  Completely immersed, the feathered predator floated to the surface, struggling to emerge with a fish in its talons.  A third, then fourth, labored wing-beat increased the height from the lake's surface.  In a remarkable finale, the fishing raptor shook off excess water, gliding ever so closely to the pool's shimmering edge again.  While positioning the fish straight ahead, torpedo-style in its talons, the osprey began stroking upward, its wriggling prey secured.  With most efficient style, this lean, flying machine had spied its quarry and with amazing desire just took it.  You thought your tackle box contained everything you needed to catch a fish, but this was truly an incredible display of "fishing perfection"! 
    Ospreys are well equipped for obtaining a meal.  They possess keen eyesight capable of precisely locating fish.  As bow-hunters realize when spearfishing, underwater targets are not where they appear, due to water's refraction of sunlight rays.  Ospreys' pale-bluish talons are tipped with nature's finest fishhooks: claws, sharp as needles.  Toes have roughened protuberances or "spicules" to hold slippery fish, and outside toes are capable of swiveling backward to join the rear toe or "hallux" (two toes clamping with two toes versus the standard three toes and hallux).  This allows grasping fish torpedo style, which reduces wind resistance while in flight.   Ospreys also have the ability to lift from water, vertically, using specialized joints at wing wrists or "carpals".  These anatomical tools distinguish ospreys as unique in the raptor kingdom.  No other birds of prey possess these capabilities.
    Ospreys, Pandion haliaetus, commonly called fish hawks or fish eagles, are neither a true hawk nor eagle.  The species is of ancient lineage and is presently classified near the, hawk-like, kite family.  It has a worldwide range, and four subspecies are presently recognized, two of which occur in North America; P.h. carolinensus in temperate North America (including Iowa) and P.h. ridgwayi in the Caribbean.
 These birds are large narrow-winged, fishing raptors, weighing between 2.5 and 4.5 pounds.  Studies report a family of with two young needs 4 to 5 fish per day.  Fish taken are generally in the range of 5 – 12 inches in length.  Ospreys are known to carry fish upwards of five miles to remote nests.
     Sexes are similar in appearance, and their sizes overlap, but females tend to be 10% larger than males.  Also, coloration on females includes dark flecking, or "necklace" on their chest.  Eyes are red/orange in immature birds and yellow in adults.  A distinctive blackish-brown stripe extends across the eye and down the side of the neck.  Typical flight has wings angled back much like sea gulls.  Flying ospreys are more often confused with gulls than with hawks.  Other field mark characteristics include wing linings that are white with dark barring, and dark carpal patches at wrist regions that are conspicuous when viewed from below.  Osprey calls consist of a series of shrill, staccato whistles, gradually rising in pitch, tewp, tewp, teelee, teelee, tewp.
    Nests may be built at varying heights upon any structure, natural or man-made, that provides a platform.  Ospreys occasionally nest on or near the ground or upon buoys over water.  Nests are usually one foot deep, four to five feet wide, made of sticks and lined with grass.  Apparently, visibility is important in nest-site selection; osprey nests provide a commanding view of surroundings.  They are usually located on prominent landforms, peninsulas or islands with few, or preferably no, tree branches higher than the nest.
    Osprey clutches consist of three or four eggs that are creamy white and heavily spotted brown. Eggs are laid at two-to-three-day intervals in late May.   After the first egg is laid, incubation proceeds 38 days and is dominated by the female.  The male provides food for the female and brood after hatching.  The female remains in constant attendance the first 30 days, providing protection from predators and the elements.  Predators include raccoons, gulls, crows and owls.  When predators are near, camouflaged nestlings lie outstretched and motionless as a natural defense. 
    At 42 days, young can tear apart fish provided by parents and around 53 days, first flight occurs.  Young of the year quickly acquire fishing skills and gradually expand their range until dispersal in late August.  Immature ospreys spend up to 20 months at their over-wintering areas in Central and South America.  Adults attain sexual maturity when three to four years of age.  Researchers estimate first-year bird mortality at 51 - 57% with adult mortality at 16 - 20% annually.  Average life expectancy is ten years.
    Ospreys were heavily affected by the biocide crash of the 1950s, which was caused by organochlorines like DDT.  Organochlorines caused eggshell thinning which led to fewer and fewer young to replenish the population.  Numbers were severely reduced throughout their range, but were hardest hit in Great Lakes and Atlantic coast areas.  Osprey populations have shown a gradual increase since DDT and similar substances were banned in the United States in 1972.  By 1981, 8,000 osprey pairs existed in the continental 48 states, and by 1994 a national survey tallied 14,109 pairs. 
    According to tribal elders of the Omaha nation, accounts of ospreys nesting along Iowa waterways are included in their oral traditional stories.  These indigenous people have lived throughout northwestern Iowa for over 1000 years.  However, no successful osprey nesting has been documented in Iowa since European settlement.  A report in 1892 indicated a nesting might have occurred along the Cedar River, but the addled osprey egg was not recognized by the Iowa Ornithologists' Union as positive proof of nesting.  In the year 2000, an osprey nesting attempt occurred in northwestern Iowa.  It is believed the pair is the result of ospreys released by Minnesota DNR in mid 1990s at Heron Lake in southwestern Minnesota, approximately 25 miles north of the nest.  No eggs were laid but this pair holds a promise for future nesting successes. 
    Male ospreys show strong fidelity to ancestral breeding areas, preferring to nest colonially where adults originated.  Female ospreys may disperse hundreds of miles from their origin, however males will generally return within about 20 miles of origin.  Due to this very low dispersal tendency by males, young ospreys are prime candidates for relocation.  Projects are designed to spread young of the population, geographically, to areas where ospreys do not nest.  This strategy will ultimately improve nestling survival and complete continental population distribution.
 With construction of lakes by Department of Natural Resources and reservoirs by U.S. Army Corps of Engineers, potential osprey habitat exists that was previously not available.  There are numerous osprey summer sightings in Iowa, but apparently these young, non-breeding ospreys return to areas where they were reared for mating and nesting.  During the last 20 years, the number of migrants through Iowa has increased as breeding populations to the north have grown.  Despite this population growth, ospreys have demonstrated little breeding range expansion.  Minnesota and Wisconsin DNR officials suggest that ospreys, in our lifetime, do not readily pioneer new breeding ranges.  Instead they experience suppressed reproduction as density of breeders increases.  To address this issue, young ospreys from Wisconsin and Minnesota are being relocated to areas with suitable habitat in southern Minnesota, Iowa, Kansas, Missouri and Ohio. 
    The Iowa Department of Natural Resources has assisted conservation partners with technical assistance, encouragement, and fish to successfully release ospreys in Iowa.  Ms. Jodeane Cancilla of the Macbride Raptor Project located near Coralville Reservoir has spearheaded this work.  Beginning in 1997 four or five young ospreys have been released annually at their facility.  Since that time, Mr. Vern Fish of the Hartman Reserve Nature Center in Cedar Falls initiated a release at their facility in 1998.  Ms. Heather Freidhof of Boone County Conservation Board and Mr. Joe Boyles of the Polk County Conservation Board coordinated a release at Saylorville Reservoir in 2000.  The U.S. Army Corps of Engineers has provided distinguished service for releases at Coralville and Saylorville Reservoir respectively.  Assisted by literally hundreds of volunteers, these conservation organizations have devoted their efforts to bring ospreys to Iowa as a nesting species.  Project fundraising is the responsibility of the conservation organizations doing the releases.  Ospreys cost about $500 per bird.  In Iowa, ospreys have two bands, a silver U.S. Fish and Wildlife Service band and a numbered, lavender band on separate legs.  A four-year minimum commitment of releasing ospreys is required at each site.  Successful osprey nesting in Iowa is anticipated in 2001.
    Dr. Larry Rymon, noted Pennsylvania ornithologist who initiated osprey relocations along the eastern seaboard, observes that 45% of the continental osprey population nest upon manmade structures.  Therefore nesting platforms have been placed near all release sites in anticipation of returning osprey usage.  Mr. Dan Hughes representing Cedar Falls Utilities, Mr. Denny Kruiehbel of MidAmerican Energy, and Mr. Todd DeerField of the Waterloo Leisure Services Division have volunteered to top trees and place poles with nesting platforms within 20 miles of release sites.  Personnel from the Crow Wing Power Company of Minnesota assists The Raptor Center of St. Paul in securing birds for Saylorville releases. 
    Young ospreys' availability for potential relocation is evaluated in early July.  Approximately 42-day-old ospreys from Minnesota and Wisconsin are located in nests where more than one young exists.  Within hours, staff of The Raptor Center in St. Paul examine the "extra" ospreys for relocation suitability.  When approved, birds are driven to release sites and placed in carefully constructed release towers or "hack sites."  Hack sites are predator proof 8' x 8' x 8' structures with bars on the front that provide visibility of surroundings.  The bars are removed when ospreys are released. Trained volunteers feed the young daily in such a manner that the birds do not imprint on people.  By quietly viewing ospreys through one-way mirrored glass, detailed observations of each bird's temperament and condition are logged.
    When ospreys are approximately 53 days of age, they are full-grown with rapidly developing feathers and are ready to be released.  The birds are actually heavier than they will be as adults, due to built-in fat reserves until self-sufficiency is achieved.  Great care is exercised to ensure that young are not startled into their first flight - at this stage, the less disturbance, the better.  Once ospreys have flown, volunteer spotters monitor the birds' movements the best they can, either from shore or in boats for the first few days.  It has been shown that young ospreys can fly better, the first time out, than they can land upon a perch.  As with other raptors, returning to a perch near the hack box can become a fatal learning experience for young flyers.  After the ospreys fledge, volunteers supplement their diets with fish at the hack site until birds begin fishing on their own. 
    These combined activities by volunteers provide tremendous opportunities for whole, outdoor-loving, families to connect with a most dynamic raptor.  These duties have become great opportunities to establish touchstones with our environment and trigger our need to be good stewards of the land.  Efforts by these volunteers are moving this project forward.  There is empowerment volunteers can build upon in other wildlife and habitat enhancement projects.  Ultimately, improving the quality of habitat will improve the status of wildlife populations. 
    We can think of Ospreys as "sentinels of clean water."   Ospreys rely upon fish for food and fish need clean water.  Ospreys also need to be able to see fish in our water, so turbidity and siltation become critical issues.  Fish need clean water, ospreys need clean water; we all need clean water.  But clean water doesn't just happen.  It requires standards of decency that can benefit everyone and everything.  Joining bald eagles, trumpeter swans, sand-hill cranes, wetland mammals and our myriad of waterfowl, ospreys can be appreciated in all water quality endeavors and provide a rewarding environmental connection for Iowans.  Moreover, as a highly desirable watchable wildlife species, it's great to see "fishing perfection" in Iowa.
    An osprey video and slide program are available from the Wildlife Diversity Program located at 1436 255th St. Boone, IA 50036.