Owl captures net vital information on birds’ migration

John L. Russell
Special to The Detroit News

Cheboygan — The annual migration of birds of prey brings thousands to the tip of lower Michigan, where the contours of Lakes Huron and Michigan join at the Straits of Mackinac.

They perch in the trees along the shore to store up energy and wait for southerly winds to create thermal updrafts that will push them over the five-mile stretch of water into the Upper Peninsula.

This annual event produces great opportunities for researchers to record the numbers and species of birds.

“By collecting all the data and studying years of research, we can tell how climate change and human activity can affect the birds, their health and activities,” said Ed Price, president of the nonprofit Mackinac Straits Raptor Watch. “This information reflects on the health of our planet, which affects us all.”

The fledgling Mackinac Straits Raptor Watch, a growing group of volunteer birders, holds owl banding and hawk watches in the spring as the birds head back north. They head to the other side of the straits in the fall to catch the birds as they head back south for the winter.

Catching the birds is a bit of an challenge.

Volunteers set mist nets throughout the forest in the Mackinaw City area and at Cheboygan State Park, where they were Friday night. Owl calls broadcast from electronic devices are hung in trees in hopes of attracting the migrating Northern Saw-whet owl, one of the smallest raptors in North America at about six inches long. The small-mesh nets are virtually invisible and stretch eight feet high and 40 feet across.

Two research assistants were camped out in a log cabin near the beach along Lake Huron, with no running water or electricity. A group of volunteers joined them recently in hopes of catching and banding owls.

“This is a great program. It’s a great opportunity to learn about the owl and its habitat,” said Kim Edgington of Port Angeles, Washington, one of the research assistants.

A graduate of Evergreen State University in Washington state, Edgington first banded birds in 2012 for a class, and this is her first time working with the Raptor Watch.

About the log cabin, where she’s been living since mid-March, Edgington says: “It’s not too bad. It sure is better than sleeping in a backpack tent for two months.”

She and fellow researcher and head bander Emily Wilmoth of Greendale, Wisconsin, will work until mid-May, when most of the migration of birds is completed.

“As of April 15, we have banded 30 Northern Saw-whet owls and two long-eared owls, and re-captured six banded owls,” Wilmoth said.

Each bird that is netted is gently placed in a Pringles potato chip container, which calms them down.

Upon returning to the cabin, the containers are weighed with the bird inside, then weighed again once the bird is removed, establishing the weight of each bird.

The wings are measured and the feathers are viewed with an infrared light, which reacts with pigment in the feathers to reveal the bird’s age. Pink feathers that appear under the light are new feathers from last fall, when molting occurred. The two female owls netted early Friday evening were healthy and at least 2 years old.

A tiny aluminum band, etched with an identification number, is gently placed on the owl’s leg, the data recorded on a sheet that will be sent to the U.S. Geological Survey’s North American Bird Banding Program in Maryland. Administered by the USGS and the Canadian Wildlife Service, similar bands have been used and recorded since 1923.

The owls are then released, gently placed in a nearby tree, unfazed by photographers capturing images of them as the owls calmly watch. “They think they are invisible because of their camouflage,” Wilmoth said.

Price, researchers and volunteers have been banding the owls and other birds of prey since 2014. It was the culmination of 10 years of effort to convince experts and others that tracking the birds was vital to learning about the environmental health of the area.

“When I first broached the idea of a hawk watch in 2004,” Pike said, “people were daunted by the amount of work and funding it would entail.

“With the help of a grant from Emmet County, countless volunteers and three years of preliminary counts, proof was established that the straits corridor was a vital hawk migration site, and we began full research and public output in 2014.”

By compiling data on the number of raptors, their health and migration patterns, researchers can get an indication of changes in the environment. Birds of prey feast on on rodents, which are abundant when the environment is healthy. The bands on recaptured raptors indicate if the species is spreading into new areas and growing.

The bird banding effort is supported by the Straits Area Audubon Society, one of 22 Audubon programs in the state.

“One of four Michigan residents is a birder,” said Kathy Bricker, secretary of the Straits Area Audubon Society. “Interest in our wildlife has increased, I think there is a deep-seated natural impulse to connect with nature — it’s beautiful and a good antidote for the angst produces in our daily lives.”

When this spring’s banding effort is complete and the birds have all moved on to other areas, so will the Mackinac Straits Raptor Watch’s two research assistants.

Edgington will head to Idaho to survey songbirds and Wilmoth will do a field trip to Russia for a month with the International Crane Association.

John Russell is a writer and photojournalist from Traverse City.

More information

■The nonprofit Mackinac Straits Raptor Watch offers field trips and educational programs throughout the year. More information can be found at www.mackinacraptorwatch.org

■The Straits Area Audubon Society is one of more than 500 local nonprofit chapters of the National Audubon Society. More information on Straits Area chapter can be found at www.straitsareaaudubonsociety.org