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Looney for Loons: Two Peaks Islanders Helping to Monitor Common Loon Behavior

Young Loon in Intermediate Plumage

Photo © Andrew Jackson

Even living here on Peaks Island year-round one may not fully appreciate the seasonal comings and goings of the loons that quietly patrol our coast in winter but seem to disappear in the summer. Most are Common Loons, but occasionally Red-throated Loons are also observed. During the winter and early spring our “looney” neighbors explore the waters of Casco Bay, Whitehead Passage, and Hussey Sound looking for their optimal intake of about 2 lbs. of fish per day. A few come into our coves such as Ryefield, Wharf, and Spar while some visit the ferry landing. To get a good sense of how many loons are around Peaks Island, one does need to scan the waterscape with binoculars.

Valerie and Patty have been putting in some binocular time to record the seasonal meanderings of the Common Loon and reporting their observations to the Signs of the Seasons (SoS) Program (1) since (mid-November 2023). This program uses volunteers’ backyards and neighborhoods as laboratories to help scientists document the local effects of climate change. Observations provided by volunteers are designed to document how climate change is affecting the timing of natural events.


The program isn’t limited to Common Loons or even to birds. At present, 23 “indicator” animal and plant species are monitored by SoS volunteers located in Maine and New Hampshire. If you are interested in joining the effort, click on this link to view the indicator species list and volunteer options.

The SoS goal is to build a rich, detailed record of the timing of the region’s seasonal changes and how they affect each indicator species. For the Common Loon this means documenting loon abundance, reproductive and migratory behavior, and relating it to climate patterns. Data collected focuses on nesting locations and reproductive success; migration dates and destinations; conditions in wintering habitat; and observed challenges to loon well-being (predation, lead poisoning, human encroachment, etc.). Volunteers’ reports are made available to collaborating scientists and resource managers working to understand and mitigate negative climate effects on indicator species.


The following questions must be answered each time we report a Common Loon sighting in coastal waters during the non-breeding season.

  •  Do you see or hear live individuals?

  •  Do you see feeding?

  •  Do you hear calls or song?

  •  Do you see territorial individuals?

Each item calls for a simple check-off of the appropriate prelisted response: “YES”, “NO”, “if YES, how many”. Winter reporting from Peaks Island was simple. It usually involved only the first two items because loons are seldom vocal or territorial during the winter when in coastal waters.

In addition to the information about loons, there is a place for information about the number of observers, type of observation (stationary, incidental, or traveling), weather, tides, and other conditions that might influence loon numbers.

For Peaks Island we have monitored two viewing points regularly since mid-November 2023):

  •  The bench along Seashore Ave near Hussey Road

The seascape is easily scanned with binoculars from this point. Many of the loons observed in Hussey Sound are seen coming into the observation area from near Pumpkin Knob in the late afternoon, either solo or in groups of 5-10. Smaller numbers tend to enter the viewing area from the East, usually swimming solo.

  • The benches along Seashore Ave near Ryefield Cove, looking out toward the Watch Tower on Cushing Island.

Loons observed at Ryefield Cove are not as abundant - usually fewer than ten at a given time, with one or two close to shore in the cove and the others in the distance near Cushing Island. Though fewer in number, the Ryefield Cove observations were interesting. Back in January we noted the steadfast presence of a single loon inside the cove at various times of day. Most surprising, however, was some unusual territorial behavior: the bullying loon on several occasions chased a pair of Red-breasted Mergansers out of the cove. This type of behavior is common in breeding territories but seldom seen in winter hangouts. Interestingly, the bully didn’t chase the eiders or goldeneyes, but the latter did keep a good distance from the aggressor. Valerie has observed similar loon/merganser confrontations on Moosehead Lake during the breeding season (see below photo series from a video). Do some loons have a grudge against mergansers year-round? More likely, the mergansers compete with loons for available fish. The eiders and goldeneyes do not eat fish, instead they eat mussels and other bottom invertebrates, so are less likely food competitors from the loon’s perspective.


Loon attacking Common Mergansers on Moosehead Lake

Video/Photos © Valerie Kelly

Peaceful female merganser with young.

Loon attacks merganser family

Loon resurfaces after attack.

Loon is congratulating himself after scattering merganser family.


In addition to the “fixed locations” of Ryefield Cove and Hussey Sound we submit incidental reports on loons observed from the ferry, along Island Ave, at Evergreen Landing, or when walking along the Backshore.

An unusual “incidental” observation occurred on December 5th when coming back to Peaks on the 2:15 ferry: a total of 51 loons were seen – one group of 16, another of 30, and then 5 solo swimmers as we approached Peaks. Other unusually high counts of Common Loons in the waters around Peaks Island have been reported in the Christmas Bird counts of 2018 (57 individuals), 2022 (70 individuals), and 2023 (62 individuals). These Christmas counts include observations from multiple places along Peaks Island’s coast and usually include sightings from a ferry trip to Portland. Are the numbers increasing? Is the Peaks Island coast becoming more popular as a winter resort for Common Loons? With a few more years of data collection we may be able to answer that question.

Now that spring is here, the loons have molted their drab winter plumage and replaced it with their characteristic tapestry of black and white feathers.

Winter Plumage

Summer Plumage

Photo © Michelle Brown

Molting leaves the loon flightless during a 3-week period sometime between January and March (2). By April most adults have their new flight feathers and are ready to head inland to their breeding lakes, leaving Peaks Island and the coast far behind. Does this mean that our monitoring is over? Not at all!

Patty will continue to monitor the Peaks observation sites during the summer, though she expects her sightings to be few and far between – only the immature (1 & 2 year olds) stay in coastal waters during the summer, although they tend to head farther North.

Valerie will be heading to her camp on Moosehead Lake, where she will switch to monitoring three coves near Lily Bay Park where she has been lucky enough to observe via kayak the day-to-day efforts of devoted Common Loon parents raise one chick in 2018 And another set of parents raise two in 2020. Will this year be exceptionally good and both pairs show up in their habitual territories and have a successful reproductive season? Fingers crossed!

In any case, the SoS reporting will need to expand from winter details to the full list of behaviors being tracked by SoS during the breeding season. This includes an additional ten questions also answered with a “YES”, “NO”, “if YES, how many”.

  •  Do you see courtship?

  •  Do you see mating?

  •  Do you see nest building?

  •  Do you see occupied nest?

  •  Do you see downy young?

  •  Do you see partially fledged young?

  •  Do you see fledged young?

  •  Do you see dead individuals?

  •  Do you see dead nestlings or fledglings?

  •  Do you see individuals at a feeding station?

In anticipation of Valerie's summer observations on Moosehead Lake we offer some background information (2) on the Common Loon and how our studies will help to answer some of these questions.

Since 1989, when researchers learned how to safely band loons, more has become known about their migratory behavior. They can travel up to 12 hrs. per day, maintaining speeds of 60-70 mph. Migrations involve solo flight during the day and evening gatherings at ‘highway rest stops’ with abundant food. Ferry Beach at the mouth of the Scarborough River is such a rest stop.

Actual departure dates depend on getting the “word” (how we don’t know) that the ice is out on their breeding lakes. Are earlier ice-outs encouraging earlier departures from the coast? This is one of the questions SoS data will help to answer. A few Casco Bay loons observed in late March were already showing off their breeding plumage and those numbers increased significantly in April. Since mid-April we have noticed a decline in Common Loons at our observation points on Peaks Island, suggesting that the migration inland is already well underway, although we are still reporting a few sightings.

Males head inland first, followed by females a few days later. About 80% of the time, breeding pairs from the prior year head to the same lake and look for the same partner. Three-year-olds, who are breeding for the first time, take off 4-6 weeks later because their molt occurs after that of the older birds. Is this nature’s way of giving the old-timers an advantage in the battle to find a territory and mate?

Once at the lake, the male’s work begins. He finds and defends a territory, followed by joining his previous mate or finding a new one. Choice of territory, mate, and nesting site frequently duplicate the prior season’s outcome, though not all loon pairs mate for life. Bachelor loons from the prior year have been observed taking over the territories and partners of their elders—often with a battle royal taking place between the males, sometimes aided by the female if loyal to her previous partner.

Once territory and mate are secured, mating takes place. Copulation is initiated by the female who seeks a suitable place ashore - a place where she can climb up on land. (Note: Loons' feet are designed for swimming, not for walking on land.) The male follows her closely, climbs up behind or next to her and immediately attempts copulation. This behavior was observed by Valerie at Moosehead Lake and described in a scientific paper (3). In the photo below the male is already back in the water, while the female is recovering on the beach. Valerie is regretting that she got her camera out too late to capture the full story.

Photo © Valerie Kelly

The nest is built (along the shore or floating nests) and one or two eggs are laid. During the 28-day incubation period both mom and pop share nesting duties to keep the eggs warm and protect them from predators.

Loon on Nest Along Shore

Photo © Michelle Brown

Loon on Floating Nest

Photo © Valerie Kelly

Two Eggs on Nest

Photo © Sam Wainright

As a rule of thumb, this all takes place before the second Saturday in July when the Maine Audubon Loon Count takes place, aiming to get a good estimate of the number of chicks born in Maine each year. Survival rates are not promising for chicks born after mid-July as it takes a full 12 weeks of parental vigilance for the chicks to begin their flying lessons and another 2 weeks before they are independent of their parents. Once the chicks are considered independent the adults leave the lake. Yet, independence doesn’t mean flying skills have been completely mastered. Another two or three weeks of practice are usually in order before the youngsters can consider migrating to the coast for the winter. This brings us up to late October or early November, leaving only a couple of weeks before cold weather traditionally hits northern Maine and lakes begin to freeze. Does this mean that climate change may have an upside? Could a later arrival of frost and ice mean better chances of survival for late loon hatches?

In closing, we offer a looney haiku for each season to help you remember the Signs of the loon’s Seasons, beginning with fall when loons start to peak around Peaks.


Leaves fall, the sea calls

Adults first, young ones later

Ocean’s bounty waits.


Families split up

New friends found, feathers molt

No flying for now


Spring melts winter’s grip

Migrate inland, claim a site

Build a nest, lay eggs.


Summer’s warmth descends,

Raise the young with tireless care,

Danger everywhere.


1. University of Maine Cooperative Extension and Maine Sea Grant coordinate the Signs of the Seasons program in partnership with the USA National Phenology Network (USA-NPN), Acadia National Park, Schoodic Education and Research Center, U.S. Fish and Wildlife Service, Maine Maritime Academy, Maine Audubon, Coastal Maine Botanical Gardens, and climate scientists and educators at the University of Maine. Current participants include UMaine Extension Master Gardener volunteers, UMaine Extension 4-H participants, and coastal groups affiliated with UMaine Extension and Maine Sea Grant, as well as other groups and individuals across the state in all 16 counties.

2. David C. Evers & Kate M. Taylor. 2014. Journey with the Loon. Willow Creek Press, Inc. Minocqua, WI.

3. S.J. Sverre and Greta & Lander Agren. 1972. Reproductive Behavior of the Common Loon. Wilson Bird Bulletin. Vol. 84:3. Page 302.


By: Valerie Kelly

Reviewed by: Sam and Patty Wainright, Marty, Michelle Brown, and Michael LaCombe

1 comentário

09 de mai.

Thank you for taking Islanders on your wonderful journey with the Loons. Much appreciation. Carol


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