Return of the Osprey
"K2 is back!" Those words sent goose bumps up my spine, and I excitedly drove out to Poplar Lake in Ramsey County to check on the friend I had not seen in three years. K2 is an osprey, one I remembered well from all the hours I had spent hand-feeding and caring for him as the "hack-site" attendant at French Regional Park in Plymouth. He had stood out as a particularly calm osprey. He was the first bird I had cared for that had migrated to South America and returned to nest in the metro area. I was thrilled to see him try to build a nest for the first time.
A product of the Twin Cities Osprey Reintroduction Project run by Three Rivers Park District (formerly Hennepin Parks), K2 was one of seven 5- and 6-week-old osprey chicks captured from their natal nests in northern Minnesota in early July 1995 and translocated to French Regional Park. (This process is called hacking, a falconers term.)
We banded the chicks with both a silver U.S. Fish and Wildlife Service band and a black alphanumeric band used by the reintroduction project to easily identify our birds before moving them to their hack box in the park. This 6-foot-by-6-foot, predator-proof box atop 15 feet of scaffolding provided the birds with a 360-degree view of the land and laketheir new home.
Six-week-old chicks are past the stage when imprinting on humans is possible, yet they are not able to fly and still need to be fed. I hand-fed them small bits of fish twice a day, as their osprey parents would have, for about two weeks.
When a bird displayed signs such as flapping its wings, flying from perch to perch within the box, landing on a perch (which requires considerable foot strength), and ripping a whole fish, we knew it was ready to fledge. Hack-site attendants then left the boxes open or placed the bird on top of the box with a plateful of fish so it could fly when it felt ready.
The fledglings instinctively learned to catch fish, their only prey, but we continued to supply food at the hack site. It made me smile to hear the raucous chorus of food begging as they congregated atop the box after their fishing had failed.
By mid-September the ospreys had mastered their fishing techniques. They began to disperse and undertake their first migration.
Ospreys remain in South or Central America until old enough to breed at age 3. The young male osprey then returns to the area where he learned to fly to find a mate and nesting territory. K2s return in 1998 signaled his successa great reward for my work cutting up bullheads, coaxing the chicks to eat, dodging osprey poop, and watching over them for hundreds of hours. K2s first nest attempt failed in 1998, but in the following years he was successful and in 2002, K2 was alive and well and producing his fourth nest full of chicks. One of his female offspring from 1999 also returned and raised a chick!
Historically, ospreys had nested in the metro area; but they had disappeared as a breeding species by the mid-20th century because of shooting, loss of habitat, and organochloride pesticides, which caused thin eggshells that broke prematurely. When park district staff and volunteers began reintroducing ospreys in 1984, no ospreys were
nesting in Minnesota south of Mille Lacs County. From 1984 to 1995, they translocated and released 144 young ospreys from six different hack sites within the seven-county metro area. The first successful nesting occurred in 1988 in Carver Park Reserve.
In the current phase of the project, staff and volunteers are monitoring the osprey population, banding chicks, and erecting nesting platforms as needed. As of September 2002, 270 wild chicks had fledged from 31 nests within the metro area, making this osprey reintroduction one of the most successful in the nation.
My involvement with this project began as a volunteer osprey monitor for the park district. The work quickly became my passion. With about 30 other volunteers, I monitored the young ospreys from sunup to sundown, keeping careful and copious notes about every observation.
As my interest and knowledge grew, so did the metro osprey population. In 1995 I was hired as one of the attendants to care for young ospreys at the hack site, and in 1997 I became a park district wildlife technician, monitoring nests, reading leg bands, recording incubation and hatch dates, assisting with banding chicks, and writing a final report on the data collected each year.
Ironically, as ospreys prosper and adapt to life near people, they fall prey to negligent human behavior. Last year, two chicks from different nests, in different areas, were found with plastic twine wrapped like tourniquets around their legs. The parent ospreys had apparently picked up twine left on the ground and used it along with grasses to line their nests. One chick had to be euthanized because its injuries were so severe. The other recovered at The Raptor Center and was released. Three ospreys were killed when they flew into the blades of a wind turbine near their nest.
As the metro osprey population grows, nests are appearing on power lines, telephone poles, light posts, wind turbines, and other human-made structures in open areas near water. If you are aware of any new osprey nesting activity in the metro area, notify Three Rivers by sending e-mail to email@example.com or by calling 763-476-4663.
Vanessa Greene, wildlife technician