Loon Biologist Explores Life and Conservation of Charismatic Northern Bird

“Loons are the rock stars of Douglas Lake,” said Holly Gedert, a member of the Douglas Lake Improvement Association (DLIA), a nonprofit organization made up of property owners.

For 33 years the DLIA Loon Committee has worked to maintain artificial loon nesting platforms, or floating islands, in several bays along the shoreline to keep the eggs and chicks safe from predators and people.

“We care so much for the loons we hear and observe every year and are eager to learn more about them and ways to help them,” Gedert said.

A Looney Life

Nearly 170 people filled Gates Lecture Hall on July 2 to listen to Loon Biologist Jay Mager give the Hann Lecture in Ornithology at the historic field research station nestled along Douglas Lake, including UMBS students, researchers and staff and dozens of visitors who live throughout the region.

“How can we have people and loons co-exist?” Mager said as he took the audience through a variety of threats to the Common Loon population. “They’re a pretty important ecological indicator species for the aquatic health of the lake.”

Dr. Jay Mager is a professor of biological sciences at Ohio Northern University, where he teaches courses in biology, ecology, animal behavior and ornithology.

Trained as a behavioral ecologist, Mager has spent most of his career studying various aspects of the life history of the Common Loon and applying what he has learned to a number of conservation and management issues facing this species.

Mager said that loons spent breeding season as far south into Pennsylvania and northern California a century ago. But over 100 years the breeding range sharply regressed to Canada and the northern U.S. as loons also face declining reproductive success (having fewer offspring), increasing mortality and decreasing survival.

Deep Dives

Loons are famous for their underwater foraging — “they can pursue fish 200 to 250 feet deep in the water” — and that’s thanks to a variety of body attributes.

The legs of the loon are positioned in the far back; they can rotate their ankles to execute turns of up to 270 degrees per second under water; unlike most birds with hollow bones for flight, loons have solid bones; and they can compress their bodies and cut through the water with little resistance or drag.

Mager said research also suggests adaptations in the circulatory system allow loons to stay underwater for about three minutes.

“Studies of other diving waterbirds similar to loons suggest that having more hemoglobin molecules within red blood cells may allow them utilize more oxygen for a longer period of time,” Mager said. “You’ll also see they’ll take a big gulp of air before they go on a deep dive.”

However, adaptations that contribute to a loon’s swimming and diving prowess come with drawbacks.

Mager said loons have a difficult ability to get up in the air to take flight and they’re “very bad” at trying to walk on land.

“It’s comical to see them waddle, push themselves up and fall forward onto a nest,” Mager said “But if you see a loon on land that is not nesting, that’s a sign that something’s not right for the loon.”

Habitat Selection

Loons will return to the same lake year after year 80% of the time, Mager said, and among chicks that are born on a lake, males more often come back to their natal area, and females disperse more.

(No, loons don’t mate for life, Mager reported.)

When comparing lake options to call home for a few months, they need to consider the availability of a variety of resources to raise their offspring because there’s an “extensive amount of parental care.”

Both male and female loons are involved in incubating eggs for up to a 28-day period. Once they hatch, the chicks are “pretty much ready to jump right in the water as little cotton balls.”

Parents feed whole fish to their chicks. They also protect them from predators such as bald eagles, snapping turtles, musky, pike, as well as from other loons that might try to kill them.

While moving along the lake, loons carry their young on their back to help protect them from underwater predators and also help them conserve heat and energy.

But Mager said the lake with the optimal habitat may not be the safest choice.

Loons can get kicked off their territory by another male loon.

“They will at times fight to the death,” Mager said about loon behavior associated with acquiring and defending the territories from other loons on a lake. “They’re nasty and will kill each other. Loons can lose their life over competing for a territory.”

To remedy some conflicts, Mager said, male and female loons use distinctive acoustic signals to try to talk it out.

The Call of the Loon

Mager played audio recordings of three kinds of loon calls he has gathered in his three decades of field work:

• Wail: Contact calls. “Where are you?” Parents displaced from chicks will wail call, and the chicks will respond and return to the parents. It’s a higher amplitude, longer call of pure tone.
• Tremolo: Charismatic laugh of the loon usually given when flying over territories. Often given in response to boaters, eagles, mammals or other loons. Marks a distraction or perceived threat.
• Yodel: Aggressive call only given by a male dealing with a threat, such as a territorial intruder.

The yodel is the main one to focus on to help a loon decide which lake to choose to live or whether to defend its territory from an encroaching loon.

The yodel has two parts: an introductory phrase (like a wail) followed by a series of two-syllable repeat notes.

Mager said the yodel in part communicates how big and strong that bird is — in other words, its “fighting ability.”

The dominant frequencies of yodels are related to male body mass.

If you’re a bigger, healthier bird, you produce yodels that have a lower frequency. And vice versa.

“Loons appear to be paying attention to these yodels,” Mager said.

When sizing up an opponent, the smaller bird with a higher voice — or so-called “pipsqueak”— may choose to not participate in the fight and move on to another lake location.

Threats to Loon Population

When people find loons washed up on shore, it’s not always due to another loon’s dagger-like bill.

Mager said loons ingest fishing tackle and die from lead poisoning.

Some people shoot loons with guns.

A lot of loons have a tough time getting off their breeding lakes to start heading to their wintering areas, especially if the winter freeze arrives too fast and the loons get iced in.

Loons lose their “flight feathers” in January and early February, so “it’s a dangerous time to be on a lake that has frozen over,” Mager said.

A number of loons have died from botulism toxicity off of Lake Michigan, Mager reported.

Others perish on their migration to their wintering areas.

“Many birds breeding in the Midwest, including northern Michigan, head due south or east and get into the Gulf or Atlantic Ocean,” Mager said.

He showed the audience at UMBS a picture of a loon bit by a shark.

Loon Conservation

Mager said his more recent research involves social behaviors of loons as well as a collaborative effort to address issues impacting loons and biodiversity.

He helped develop of a national loon stewardship group — a collection of working organizations focused on the conservation of the Common Loon such as the Maine Audubon, Vermont Center for Ecostudies, Birds Canada, Loonwatch (Wisconsin), Montana Loon Society, Biodiversity Research Institute, Ricketts Conservation Foundation, National Loon Center, Journey North, and Michigan Loon Preservation Association.

The Loon Rangers along Douglas Lake are part of the Michigan Loon Preservation Association, sharing their loon tracking data with the organization.

Gedert said she took away a lot of helpful information from Mager’s lecture at UMBS to bring back to the DLIA.

“There are changes we can make to our operations to enhance our loon nesting program and strengthen our contribution to loon conservation,” Gedert said.

“Jay’s work is fascinating,” said Anne Covy, a member of the loon committee who has a home along Douglas Lake with her husband Dale, who also attended the loon lecture. “All of us have a shared collective interest in loons. We’re grateful Jay took the time to be here and that we learned so many new things about these beautiful creatures.”

The group shared this update on July 4, two days after the lecture: “We have 6 loon chicks on Douglas Lake. The adults are nurturing their chicks near the territories of Silver Strand, Manitou Bay and South Fishtail Bay. Please be aware of the families and give them space. The loon chicks are still vulnerable.”

Follow the loon nesting activities on Douglas Lake on the DLIA website.

The public is invited to free, public lectures at the U-M Biological Station every Wednesday at 7 p.m. through July. View the full schedule of 2025 speakers and topics.

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