Hacking Project Holds Promise for the Return of the Osprey

A shadow scudded across the woods on a sunny day last spring. I craned my neck skyward to see a large, dark bird skimming the treetops. It was bigger than a redtail, larger than a turkey vulture, and not the right shape for a bald eagle. Bushwhacking through the woods, I found its eventual perch. What a thrill to discover what I was tracking: an osprey.

It was May in northern Illinois. The bird may have been en route from Venezuela to the far reaches of Canada. Or, was this the final leg of a 3,000-mile journey from Suriname? Could it be nesting here in Illinois? The Osprey Recovery Project in Illinois intends to answer questions like these, and to encourage osprey to nest here in Illinois.

In 2012, Illinois Department of Natural Resources (IDNR) biologists Patrick McDonald and Joe Kath created a plan for the recovery of breeding osprey in Illinois. Years of habitat loss and degradation of waterways led to the decline of these magnificent raptors over the course of the 20^th century. The introduction of DDT after World War II dealt another blow to osprey. The 1970s brought much-need regulation of pesticides and legislation such as the Clean Water Act. Raptor populations rebounded, but the osprey has yet to re-establish former breeding numbers in Illinois. In 1997 it was listed as a state-endangered species in Illinois.

McDonald, Kath, and a suite of other biologists hoped that the Osprey Recovery Plan would bump the bird’s status from state-endangered to state-threatened—or, better yet, remove the bird from the list entirely.

The multi-year recovery plan is based on a process called hacking. Young birds are moved, or translocated, from one location to another. The chicks are placed in a structure called a hack box, which affords protection from predators and a view of the expanse of the birds’ new habitat. At the hacking site, biologists carefully monitor the birds, feed them, and allow them to learn their surroundings. When ready to fledge, the birds are released. In time, they begin the long migration to wintering grounds in South America. Osprey exhibit site fidelity—in other words, they return to their original nesting area. The hope is that osprey hacked in Illinois will return to Illinois for breeding.

In 2013 under the planning and guidance of McDonald, the multi-year project was set in motion. Dr. Tih-Fen Ting, associate professor of environmental studies at the University of Illinois Springfield, received a U.S. Fish and Wildlife Service grant through the IDNR. Ting and her crew set to work preparing the first translocation of osprey to Illinois. The initial set of 24 chicks from the Chesapeake Bay were translocated to Anderson Lake Fish and Wildlife Area in Fulton County.

In subsequent years, sources of chicks included Lake Barkley, Kentucky, and Massachusetts. Chicks have been hacked at Lake Shelbyville in Shelby and Moultrie counties since 2014, and Banner Marsh State Fish and Wildlife Area in Fulton County since 2016.

In total, 82 birds have been translocated in the program.

“All birds have a federal band on the left leg and a [green] colored band on the right leg,” Ting explained. “Each year, different birds [are] also given different colors of breast paint to facilitate their sighting and tracking.” Her students assist with feeding and monitoring the health of chicks in the hack box, as well as tracking their movements until migration.

Patience pays off in multi-year restoration projects of any kind. The research team was able to track four hacked birds, using satellite transmitters, between 2016 and 2019.

“One ended up at the edge of Amazon Basin in Colombia,” Ting reported, “and three reached southern Mexico.” It’s one thing to look at range maps and see the general migrations of species. It’s another to track individuals that you’ve been “up close and personal with” on their trans-continental journeys.

In 2019, six years into the Osprey Recovery Project, a hacked osprey from 2017 showed up at Lake Shelbyville. This was cause for celebration—and cautious optimism. With the catchy name “48D”, this male originated in Virginia and was hacked at Lake Shelbyville in 2017. When 48D returned, he had an un-banded mate, but he wasn’t mature enough to produce offspring. He came back to Shelbyville this year and again, had an un-banded mate. Although there have been no offspring thus far, the news is auspicious.

“It is encouraging to have our own hacked osprey return to the site where it fledged,” said Ting. “48D is still too young to breed but we are hopeful.”

There was another encouraging sighting this year, when an osprey hacked in 2014 at Lake Shelbyville was spotted in Kentucky. It isn’t known if this male, known as 11D, was breeding at the Kentucky site. Researchers will be keeping an eye out for him next year.

In addition to Ting’s Osprey Recovery research team, collaborators include IDNR biologists, the U.S. Army Corps of Engineers, Illinois Audubon Society, Scouts and community groups. Power companies, wishing to prevent accidents sparked by osprey on power lines, have donated poles and assisted with construction of nest structures for the birds.

The Osprey Recovery Project is an ambitious endeavor with lots of moving parts. Why do so many people join forces to bring osprey back to the Prairie State?

“Efforts to recover threatened or endangered species such as ospreys in Illinois,” explained Ting, “are necessary to keep biodiversity strong so that future generations can benefit from these wonderful creatures.”

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Valerie Blaine has worked as a naturalist for more than 40 years, from the prairies and woodlands of Illinois to the shores of the San Francisco Bay. She earned a master’s degree in forestry and a bachelor’s degree in botany from the University of Illinois. Blaine retired as the Nature Programs Manager for the Forest Preserve District of Kane County.