Ask the Scientist

We have listed some of the common questions we receive by category. Scroll through to learn all about loons!

Distribution, Appearance, Evolution, Longevity

1) Where are common loons Found?

The common loon, (scientific name: Gavia immer), breeds on freshwater lakes from Alaska and British Columbia east to the Maritime Canadian provinces, and south to several northern states in the contiguous United States, Greenland and Iceland. The breeding range includes parts of 14 northern United States.

loon range

Range of Common Loon
Source: Evers et al. 2010

2) How long do loons live?

As of summer 2019, the oldest known common loon was a female marked with colored leg bands as an adult in 1989 at Seney National Wildlife Refuge in Michigan’s Upper Peninsula. Since females do not settle on territories until at least 5 years of age, this bird is certain to be at least 35 years old. The oldest known male was banded as a chick in 1987 (also at Seney NWR) and was thus known to be exactly 32 years old in summer of 2019. Another female in Oneida County, Wisconsin is at least 31 years old. Still, these ancient individuals are the exceptions. Most individuals only survive into their teens and 20’s. An analysis of the known age population in Wisconsin showed that about 25% of all breeding adults are under 10 years of age, 60% are between 10 and 19, and the remaining 15% are 20 years or older.
Source: Piper et al. 2015, 2018; Damon McCormick, (Common Coast Research and Conservation), personal communication.

3) Are there other species beside the common loon?

There are 5 species: the Common Loon (Gavia immer); Arctic Loon (Gavia arctica); Red-throated Loon (Gavia stellata); Yellow-billed Loon Gavia adamsii); Pacific Loon (Gavia pacifica).

The Common Loon (Gavia immer) is the most abundant of the five species found worldwide. The breeding range is the northern plains of the US and across Canada. It is recognized by a striking black-and-white checkered back, glossy iridescent black head, white belly and wing lining. There is the characteristic white necklace around the throat. Males and females look the same, although males are generally larger.

common loon swimming
Common Loon

The Red-throated Loon (Gavia stellata) is the smallest of the five loon species and the only one that can become airborne without first running across the water’s surface. This species breeds in Arctic portions of Eurasia and North America. It takes its name from a triangular patch of chestnut red on its throat. Its head and neck are a soft slate-grey color, and the back of its neck is streaked with fine white lines. Its wings and back are brownish grey with a little red marking. Its underbelly is white.

Red-Throated Loon
Red-Throated Loon

The Pacific Loon (Gavia pacifica) is about half the size of the Common Loon, has a pearl-grey crown and nape, and shows several long vertical stripes on the sides of its neck. This species has a northerly breeding range that extends west from northern Quebec across most of the Alaska and into Siberia.

Pacific Loon
Pacific Loon

The Arctic Loon (Gavia arctica) is closely related to the Pacific Loon, which resembles it closely in size and appearance. Arctic Loons, however, breed chiefly in northern Europe and Asia; a few breed in Alaska.

Arctic Loon
Arctic Loon

The Yellow-Billed Loon (Gavia adamsii) closely resembles the Common Loon, although it is slightly larger and has a yellow-white bill – the lower half of which angles upward. This species is quite rare, and breeds in northern Alaska and Arctic Canada.

Yellow Billed Loon
Yellow Billed Loon

Source: Walter Piper, Chapman University

4) When did Loons first evolve and to what other birds are they related?

A recent taxonomic analysis of all major bird groups, based on DNA sequences, placed loons in a giant group of water birds (the Aequorlitornithes) and in the same evolutionary cluster as penguins, pelicans, herons, grebes, and cormorants. Surprisingly, loons are quite distantly related to ducks and geese, having split from that evolutionary lineage some 70 million years ago. The consensus at present holds that loons are related to the genus Colymboides, which is known from about 40 million years ago.

Source: Prum et al. 2015; Storer 1956

5) How do loons survive in a marine environment?

Loons are aquatic birds adapted to both marine and fresh-water aquatic environments. While in marine environments, a pair of salt glands (supraorbital glands) are located above the eyes, absorb excess salt from the blood and discharge a salt solution into the nasal cavity.

Source: Kevin Kenow, U.S. Geological Survey

Basic Behavior

6) When do common loons arrive in northern lakes?

As soon as the ice is out in the spring on our northern lakes, the loons arrive to begin the nest site selection and mating ritual. The males arrive first, followed by the females. Often they will gather in open water such as rivers before their nesting territory lake area is ice free.

Source: McIntyre, 1988

7) Can loons walk on land?

Unlike ducks and geese, loons cannot walk on land; their legs attach at the posterior end of their body, in order to make them more efficient at propelling themselves underwater. To move across land they must “skootch” awkwardly by resting on their chests and driving themselves forward with repeated thrusts of their legs. Because of their awkwardness on land, loons venture onto land only when mating or nesting or when severely injured.

Source: McIntyre 1998; Piper et al. 2012

8) How deep can common loons dive?

Common Loons have solid bones unlike other birds making them less buoyant. They are extremely powerful, fast swimmers. They can dive to great depths, down to 200 feet (60 meters) or more, and they can stay underwater for five minutes in search of food and to travel.

Source: Kevin Kenow et al. 2018

9) What do the “Calls” of common loons mean?

Common Loons produce a great variety of vocalizations, some of which carry long distances and others that are soft and function as communication between pair members or between adults and chicks. Not all loon calls have been described, so it is difficult to provide an exact count of the number of call types. Following is a list of several of the best known loon calls and their likely meaning.

The yodel is a loud, lengthy call, emitted by males only, that functions in defense of territory and chicks. Yodels are heard much less frequently than most other calls but occur when territorial intruders are flying over a lake or have just departed from it. Males yodel frequently when defending small chicks, especially when they have two chicks instead of just one, as the yodel is an effective means to prevent intruders from landing and approaching. The yodel of each male is unique, and it conveys information about his body size. Old males yodel far more often than young males. This is thought to reflect desperate efforts of older males to hold onto their territories for an additional year or two near the end of their lives.

The hoot is a short, soft single note produced by pair members in the presence of their mate. While we do not understand the precise function of the hoot, it might serve to maintain a strong pair bond.

The wail is the call most frequently heard by humans. A loud, long-range call that can occur as one, two, or three notes. The wail seems to function as a contact call that notifies a pair member of the location of its mate, after they have become separated. The wail clearly also serves as a low-intensity alarm call, because it is often given when eagles pass overhead or are perched nearby.

The tremolo is the familiar, loud call that sounds like human laughter. But sounds are deceiving, as the tremolo is chiefly a close-range alarm call that adult loons produce when they or their chicks are threatened by eagles, large aquatic vertebrates, or humans that venture too close to them.

Hormonal changes in the voices of loons do occur over time. The older the bird, the more aged the voice sounds, similar to that of humans… the older we get, our voices change as well.

Source: McIntyre 1988; Walcott et al. 1999; Mager et al. 2007, 2012; Jukkala and Piper 2015

The loon has held a special place in the imagination of humankind since the earliest civilization. The striking symmetry of its plumage, its soulful cry, and its ability to seemingly vanish underwater have inspired legends of magical mysticism. Even today, few can hear the cry of the loon drift across a dusky lake without sensing an ancient spirit and believing that magic can, indeed, exist among the mists of northern lakes.

10) When do young common loons return to breeding lakes?

The young loons, both male and female, stay in their winter and migratory waters and may move up the coastline elsewhere for 2-5 years before returning to the vicinity of their natal lake to then seek a mate and a territory. Males tend to return nearer to their natal territory than females. Both sexes tend to wander and use many different lakes as “floaters” for 2-3 years before settling.

Source: Walter Piper et al. 2015; Anim. Behav. 104:155-163

11) Where do common loons sleep?

Common Loons sleep over open water, often tucking their long bills into their scapular feathers (in the wing) while doing so. Short naps are common throughout the day and average 14 minutes, while nocturnal sleeping bouts last an average of 54 minutes.

Source: Paruk 2008

12) What do common loons eat?

Common Loons eat mainly fish, but they also consume crustaceans, snails, salamanders, leeches, aquatic insects, and frogs. Most food items are swallowed underwater, but they bring large prey to the surface and may take several minutes to manipulate a large fish before swallowing it head first. Like all birds, loons have a gizzard, which is a muscular part of the stomach responsible for crushing very hard body parts to aid digestion. Loons swallow small pebbles, which act like teeth within the gizzard which thus help to grind up bones and shells.

Source: Merrill et al., 2005; Gingras and Paszkowski 2006

13) What are the predators of common loons?

Although their large size makes them safe from most other animals, adult common loons are attacked and killed by bald eagles (Haliaeetus leucocephalus) on occasion, especially while sitting on nests. During winter on the ocean, some loons undoubtedly fall prey to tiger sharks (Galeocerdo cuvier), which prey on many marine birds. Chicks’ small size and limited mobility make them vulnerable to a wide range of predators, including eagles, gulls, snapping turtles (Chelydra serpentina) and large fishes such as muskellunge (Esox masquinongy). In addition, chicks are occasionally killed by territorial intruders. Male loons that usurp a territory almost always kill the chicks of the male that they have evicted.

Source: Gudger 1949; Paruk et al. 1999; Cooley Jr et al. 2019

Because loons nest on shorelines or near the water’s edge, their nests are vulnerable to predators, such as raccoons, skunks, river otters, eagles, turtles and large fish. If adults leave a nest, crows, ring billed gulls, ravens and bald eagles will take eggs. Human disturbance by boaters and others may result in a loon leaving its nest, making the nest vulnerable to predation. We must stay at least 150 feet away from these birds and not intrude on a nesting pair.

Source: Evers et al. 2010

The impact of people on common loons takes many forms. It includes disturbances from recreational activity, habitat loss from lakeshore development, entanglement of birds in fishing hooks/line, striking with boats, poisoning of loons caused by ingestion of lead fishing tackle, jigs and sinkers, aquatic debris, toxic chemicals such as mercury and residues from oil spills. A small lead fishing sinker will poison a loon causing certain death in 2-3 weeks.

Source: Evers et al. 2010

14) How far can a common loon fly in a day?

A U.S. Geological Survey study found that a common loon can travel 670 miles within a 24 hour period and can fly upwards of 75 mph. While migrating, they reach heights of more than 3,000 feet. Among the mysteries of migration, tracking the movements with satellite telemetry and archival geolocater tags has helped provide insights of loon migration.

Source: https://umesc.usgs.gov/terrestrial/migratory_birds/loons/migration.html

15) Are common loons bothered by insects, as humans are?

Nesting birds often cope with harassment from biting insects. A black fly (Simulium annulus) feeds on the blood of nesting common loons. This infestation may cause nesting failure if it is so bad the loons abandon the nesting eggs. The outbreak of these flies lasts only one or two weeks, but can be a horrible experience for the loons. The violent shaking of the head and diving below the water surface are the only means the loon has to repel these pests.

Source: Walter Piper et al. 2018

In some years, black fly infestations are so disruptive to incubating loons that they are continuously driven from their nests by the flies biting around their eyes and fleshy areas at the base of their bill. This can cause a lack of adequate incubation and nesting failure. In these cases, the loons will attempt to re-nest and hatch young later in the summer.

Source: Carrol Henderson, National Loon Center Board of Directors

16) Why do common loons gather in groups of 4,6 or even 10 during late summer?

Such “social gatherings” in late summer consist of five kinds of adult common loons: 1) territorial pair members from adjacent territories that have tried and failed to produce young, 2) former territorial pair members that have been evicted from their lakes and have not yet found a new territory, 3) territory pair members whose chicks have reached 4 weeks of age that are visiting a neighboring territory as a means to “decoy” intruders away from their chicks and territory, 4) young adults seeking to learn about territories and possibly evict a resident breeder in order to settle, and 5) territorial pair members from the lake where the loons have gathered. Although social gatherings often appear peaceful, they are often punctuated by violence, because participants include individuals that are likely to battle each other in the coming years for territory ownership.

Source: Walter Piper et al. 1997, 2006, 2008; Paruk 2006

17) What is the purpose of the penguin dance?

The penguin dance is often observed when a common loon is under stress as when boaters or potential predators have approached too close to their nest or family. If you cause a loon to do the penguin dance – back off. This “penguin dance” is an explosive display of strength in which the loon swims upward so fiercely as to rear up, cobra-like, with its neck curved in a graceful arch, and its feet rapidly pound the surface of the lake.

Source: Carrol Henderson, National Loon Center Board of Directors

A loon’s leg power is also demonstrated in courtship and during times of peak alarm when a loon will literally run in place on top of the water. While the loon’s wings may be splayed out for balance for some of the dance, the most impressive seconds are when the loon’s body is slicked down, wings folded, and body raised out of the water on kicking legs. This also serves as an exercise for wings and to realign flight feathers. The feet propel the body upward in the water while flapping wings. This display makes the loon appear larger to help it ward off intruders.

Breeding Behavior

19) Are all common loon feathers black/white?

Common Loon adult breeding plumage consists of a broad black head and neck with a greenish, purplish or bluish sheen. It has a black bill, sometimes with a pale tip, and red eyes. The neck is encircled with a characteristic black ring and has two white necklaces of eight to ten short streaks on the upper fore neck. It has a noticeable collar of white, parallel lines forming a large oval on the neck. The upper parts are blackish or blackish grey, and each feather has a small white spot on it. The upper wing is blackish with small white spots on the non-primary coverts, the under wing is paler with white coverts (feathers that cover other feathers), while the underparts are pure white. The tail is blackish. Adult common loon non-breeding plumage is brownish with a dark neck and head marked with dark grey-brown along with some brownish color particularly on the rump feathers. Eyes are surrounded with white and eyelids are pale.

Source: McIntyre 1988; Evers et al. 2010

20) How can you tell the difference between common loon males vs. females?

Males and females cannot be distinguished by their plumage, which is identical. However, males are about 25% larger than females, so they can often be told apart if side by side. In particular, the head of males sometimes appears decidedly larger. Only males produce a yodel call that they use to defend their territory and chicks, so a yodeling loon is certainly a male.

Source: McIntyre 1988; Jukkala and Piper 2015

21) How many eggs are laid by common loons?

Over 70% of all common loon clutches usually consist of two eggs, but one-egg clutches also occur commonly. In some cases, one-egg clutches occur because an egg predator consumes the first egg before the second one can be laid. Breeding females occasionally lay three eggs, although three-egg clutches make up less than 1% of all clutches laid. Four eggs have been reported in loon nests in multiple populations, but these typically occur when a pair abandons a first nesting attempt and then reuses the nest without dumping out the first two eggs.

Source: Nelson 1983; Zicus et al. 1983; McIntyre 1988

The eggs are large, approximately 2.08″x 3.52″ and can weigh 4.94 oz to 5.64 oz. The second egg is somewhat smaller than the first. Loon eggs are sub-elliptical to ovoid in shape. Their color varies from a deep olive to a light brown. Most eggs are olive brown and have dark brown or black irregular spots.

Source: McIntyre,1988

Males select the nest location, usually on an island or along a marshy or boggy shoreline, and females typically lay two eggs, incubated jointly by the pair for about 28 days. Parents feed the chicks most of their food through the first several weeks and continue to feed and defend them through week 11.

Source: Walter Piper, et al. 2018

21-1) Which of the pair of loons selects the nesting site?

Males choose the nest location for reasons we do not totally understand, even though females of course lay the eggs.  Male choice of nest location has important ramifications for loon behavior ecology. Since males select the nest location, they have a stronger stake in remaining on a territory once they settle.

Source:  Walter Piper, et al. 2008

22) Loon nesting patterns: Do both sexes incubate the eggs?

Loon eggs are seldom left alone, as predators relish an easy tasty meal. A study done in 2005 shows that both males and females spend almost equal time incubating nesting eggs. The daytime effort, however, varies greatly, with males covering 68.8% of the day-time duty, and only 3.7% of the nighttime duty. Females spent 23.8% of the day-time duty, and 95.8% of nighttime duty. The balance of the day, 5.1% of the time, the nest was empty of adults. It is believed that the males are ready to defend the territory and nest during the day, while less so at night.

Source: Goodale et al. 2005

22-1  Why are male loons protective of territories and nesting sites?

If a male loon is evicted from a territory he not only loses the territory, but also the knowledge of where to nest on that territory.  He must settle on a new territory and learn by trial and error where to nest. Females, on the other hand, do not choose nest locations, so they have less to lose by being evicted from a territory.  This may explain why males have an extra stake in remaining on a familiar territory and helps explain why males often fight to the death for territory ownership, whereas females rarely do so.

Source:  Walter Piper, et al. 2008

23) At what age do common loons first breed?

Based on long-term studies of loons in Wisconsin and New England, we have learned that the youngest age at which Common Loons settle on breeding territories is 4 years old, though most loons settle at age 5 or later. Females are usually older than males when they settle. Young males and females typically spend at least 2 years looking for a territory before settling.

Source: Walter Piper et al. 2015

24) Do common loons mate for life?

No, loons do not mate for life. Their mating system could be described as serially monogamous. Loons form a strong attachment to their breeding territory and try hard to hold on to it. When evicted from their territory by a competitor, a male or female retreats to a nearby lake, recovers, and looks for a new territory (and mate). For their part, loons whose mate is evicted do not follow that mate to a new lake. Instead they quickly form a pair bond with the loon that evicted their mate. Since eviction is a common occurence and loons are long-lived animals, most adults are paired with two or three different mates during their lifetimes.

Source: Walter Piper et al. 2015

25) What is the incubation period of common loons?

Copulation can occur 2 or 3 times before egg production. Generally, one egg is laid, followed by the second egg, typically one day later. Incubation of these eggs is 26-31 days. The first egg may hatch one day earlier than the second, but occasionally they will hatch on the same day. Both the male and female incubate the eggs.

The chicks hatch in late May to early July. Chicks can swim right away, but spend time riding on a parent’s back to rest, conserve heat, and avoid predators. After the first day or two of life, the loon family moves to a “nursery” area to raise their young. They usually do not return to the nest after 2-3 days of age.

Source: McIntire, 1988

26) Why the red eye?

Like many animals, common loons use their appearance to signal that they are in a breeding condition. Although there has been much speculation about the reason for the red eye, it is likely that the red eye, like the bright black and white plumage, is simply part of their breeding condition. Loons have eyes that are chocolate brown during the winter.

Source: Walter Piper, Chapman University

The red coloration is thought to help it identify other loons from far away, and may aid in seeing underwater. The red eye color may filter out blue and green light. The eyes are cinnamon to walnut brown at hatching, starting to turn red in the first winter and spring.

Source: Evers et al. 2010

27) What is a common loon territory?

Male and female common loons must acquire a breeding territory in order to reproduce, either by eviction and becoming an established territory owner, replacing a dead territory owner or founding a new territory on a vacant lake. Loons are territorial birds, and a mated pair of loons will defend an area of water from other loons. Small lakes, generally those between 13 and 125 acres, can accommodate one pair of loons.

Source: Walter Piper et al. 2000

Territory holders seldom desert a territory. Instead, they defend the territory from a parade of intruders seeking to evict them. At such times, males often emit the loud, complex yodel call, which discourages landing of flying non-breeders. Aggression by male and female breeders towards intruders includes lunges, chases on the water’s surface, and battles in which two opponents grasp each other’s heads, beat each other repeatedly with their wings, and dunk each other’s heads underwater. While male evictions sometimes culminate in the death of the former resident, female battles rarely do.

Larger lakes may have more than one pair of breeding loons, with each pair occupying a bay or section of the lake. A territory is a place where a pair raise their young. Typically, it is located in a shallow and protected bay out of the wind, with open water and small fish for food.

Source: Walter Piper et al. 2008a

28) How do common loons claim a territory?

One-year old common loons and many two year-olds do not visit their natal breeding grounds at all, but instead migrate northwards up the Atlantic coast, summering anywhere between the Carolinas and the Canadian Maritimes. About 20% of all young loons do not return to the breeding grounds until age 3 or 4. Once on the breeding ground, young loons search for a territory, preferring to settle on one that closely resembles their natal lake in size and pH. However, they spend more than 2 years on average searching for a territory before settling.

Source: McIntyre 1988; Piper et al. 2013; 2015

Most loons acquire breeding or alternative plumage in their third year, at which point they return to the breeding ground. Age at first breeding ranges from 4-11 years. Hence, young adults, especially males, typically spend 2 or more years wandering in the vicinity of their natal lakes before establishing territories. Clearly, young loons in search of territories focus their intrusions within a small area in the vicinity of their natural lake.

Source: Walter Piper et al. 2000; Walter Piper, unpublished data; Evers et al. 2000

29) Why do common loons behave so aggressively towards territorial intruders?

Both female and male common loons face two threats from territorial intruders. First and foremost, the intruders – usually young males or females between 3 and 10 years of age – are looking for territories and often try to evict breeders by defeating them in violent battles. Eviction, which happens with equal frequency in males and females, is a common way for a young loon to acquire a territory. Second, intruders occasionally attack and kill chicks – especially small ones – so pairs try hard to keep intruders away from their chicks.

In fact, the intruding loon uses the presence of chicks in a territory as a signal indicating high territory quality, so breeding pairs attempt to hide chicks from intruders so that the intruders will not spot the chicks and return the following year and try to evict them. Loon families have a special behavior pattern called “dive and scatter” that they use in an attempt to hide their chicks, when they spot intruders flying overhead. The behavior requires that both parents slide gently underwater and swim to the middle of the lake to draw intruders to them, while the chicks slide underwater and swim quickly to the nearest shoreline, where they hide among emergent vegetation.

Source: Walter Piper, et al

Migration, Wintering

30) Where do common loons live in the summer?

The Common Loon breeds on freshwater lakes across North America from Alaska and British Columbia east to the Maritime Canadian provinces and south to several northern states in the contiguous United States, Greenland and Iceland.

Source: Evers et al. 2014; Taylor, 2014

31) Where do common loons go in the winter?

Common Loons that breed on freshwater lakes of North America generally winter along the coasts of the Atlantic and Pacific oceans, including the Gulf of Mexico and Gulf of California. Among radio marked and/or geo-tagged adult loons from lakes in Minnesota, Wisconsin and the Michigan Upper Peninsula, 82% wintered in the Gulf of Mexico. 15% wintered in offshore waters of the Atlantic Ocean, and 2% wintered in Indiana or Kentucky reservoirs. Adults initiate fall migration first, followed by the young of the year, which also primarily winter in the Gulf of Mexico.

Source: Kenow et al. 2018

32) Do common loons vocalize in winter?

Loons do vocalize with each other in the winter, although to a lesser degree than in summer. Since the pairs are solitary in winter, they communicate less with each other. Daily activity in winter is flock-feeding for fish or even solitary feeding. In the evening, loons have been observed congregating in larger flocks.

Source: Kate Taylor, Biodiversity Research Institute

32) What are the feather colors in winter?

Loons begin to molt their summer plumage (alternate or nuptial plumage) in late summer and before the southern migration. They retain flight feathers but all others are molted. After arriving in wintering grounds, a complete (basic plumage) molt to a gray/brown color occurs in January and lasts until early March. The adult wintering feather color is much like the juvenile feather coloring. In the fall, many people believe all loons they see are juvenile loons, but both are still present and look much the same. In late winter and just before the northern migration, the summer breeding plumage molt occurs. Adult loons are flightless during the winter.

Source: McIntyre,(1988)


33) How do I get plans for a common loon nest?

Common Loon nesting platforms may be helpful and can contribute to successful nesting – if they are built properly, placed in strategic locations, and closely monitored and managed from late April through mid-June. They are most successful 1) in protected bays or coves away from boating traffic, 2) if they are on western or northwestern portions of lakes where they are more sheltered from prevailing northern or northwestern wind-driven waves, and 3) if they are among the edges of stands of emergent plants near shore rather than in the open lake. It is usually best to collaborate with other lakeshore owners or a lake association and experienced loon platform managers to come up with a comprehensive loon nest platform strategy and to discuss if platforms are even desirable for a particular situation.

Plans for loon nesting platforms are available in “Woodworking for Wildlife” by Carrol Henderson. It is available from Minnesota’s Bookstore in St. Paul for $19.95. Their website is www.mn.bookstoref@state.mn.us and their phone is 1-800-657-3757. The book has information about aluminum nesting rafts and directions for making the Novak cedar timber nest platform and the Dugas PVC nesting platform. In Minnesota, all loon nesting platforms must be registered with the local sheriff’s office as would other structures like swimming rafts, and they should have reflectors on all four sides to minimize the safety hazard to boaters.

The Big Mantrap Lake Association has one of the most successful management programs in Minnesota. Big Mantrap Lake is a 1556 acre lake that supports about 24 pairs of loons, and about half of those pairs nest on platforms. Their website is extremely helpful in learning how to help loons: https://mantraplake.org/the-lake/ loons.

Source: Carrol Henderson, National Loon Center Board of Directors.
Other sources of information include:
DeSorbo et al.
Midwest Floating Islands, midwestfloatingislands.com

Loon nests must be placed carefully so as to attract loons and not be in the way of other water/recreational activities of humans. Typically, smaller lakes of 100 acres or less support only one nesting pair, while larger lakes can support more than one pair. Nests are built with aquatic vegetation, moss, mud, pine needles, leaves and other plant material. Generally, nests are on or near a shoreline completely surrounded by water, such as islands or emergent vegetation.

Source: Walter Piper, et al. 2002

34) How many common loons are found in Minnesota?

Estimating the number of common loons distributed across their wide and sometimes remote North American range is a challenge. However, through detailed surveys and projections by professional biologists by geographic regions, states, provinces and countries, a reasonable estimate can be developed.

The unit most commonly used for tracking loon populations is the number of territorial pairs. Most breeding loons are found in Canada; less than six percent of the population is found in the United States. While populations of Common Loons remain relatively large, significant declines have been documented across their Canadian range over the past two decades. Close monitoring will be necessary.

RegionNumber of Territorial PairsPopulation Trend
New Hampshire285I
North Dakota14D
United States13,782S
British Columbia25,000S
New Brunswick1,100D
Nova Scotia1,200D
Canada Total243,000D

(Key: Stable =S, Decline = D, Increase = I)
Source: Evers et al.

In 1994, the Minnesota Department of Natural Resources (DNR) implemented a Loon Monitoring Program. Results from the monitoring program indicate that Minnesota’s Common Loon population has been stable over the last two decades. Minnesota has the largest population of common loons in the lower 48 states with about 12,000 birds. Wisconsin has about 4,400.

Source: Evers et al. 2010

35) When was the common loon named Minnesota state bird?

On January 17, 1961, House Bill No. 79 proposed that the common loon (Gavia immer) be adopted as the official state bird of Minnesota. It was approved by the Minnesota House of Representatives on February 18, 1961. Governor Elmer L. Anderson signed the bill on March 13, 1961.

Source: https://www.netstate.com/states/symb/birds/mn_common_loon.htm

36) Is the common loon a protected species?

Yes, all loons are protected by federal and state laws. Federally, they are protected by the Migratory Bird Treaty Act of 1918, and they are protected by State statutes as well. The Migratory Bird Treaty Act makes it illegal to take, possess, import, export, transport, sell, purchase, barter, or offer for sale any migratory bird or the parts, nests, or eggs of such birds except under the terms of a valid Federal Permit.

Source: US Migratory Bird Treaty Act of 1918

37) In Minnesota, what public resource management agencies are involved with common loon conservation?

The Minnesota Department of Natural Resources (DNR) is entrusted with the conservation and management of migratory birds including Common Loons. Within the DNR, the Nongame Wildlife Program is specifically responsible for carrying out loon surveys, educational projects, publications, protection, management, and conservation. That program has been operational since 1977. In addition, the Minnesota Pollution Control Agency operated a “Get the Lead Out” educational program from 2000 to 2010 to urge anglers to switch to nontoxic fishing jigs and sinkers to protect loons and other wildlife from lead poisoning. They will be renewing that program in 2020 with funding from Deepwater Horizon oil spill remediation funds.

38) In Minnesota, what should I do if I find a dead loon, an injured loon, or if I see boaters harassing or disturbing loon nests and loon families with chicks?

If you need assistance with a loon-related issue, such as an injured or dead loon or people harassing loons, call the DNR. Their statewide info number is 1-800-652-9093 in St. Paul. They can connect you with the local nongame wildlife specialist or conservation officer. The DNR regional offices are in Bemidji (218-308-2700), Brainerd (218 203-4300), Grand Rapids 218-328-8780) and New Ulm (for loons in the Willmar area—507-733-1200). Your other key statewide DNR Nongame Program contact in St. Paul is loon expert Lori Naumann at 651-259-5148. When calling the regional offices, you can ask for the nongame wildlife specialist or a conservation officer for the local area where the loon problem is located. If the call is about an actual violation, the Turn in Poachers (TIP) phone line is 1-800-652-0093.

Source: Minnesota Department of Natural Resources

39) Have other questions?

Please send us any questions!
Email: info@nationallooncenter.org

This work was compiled by the following biologists and conservationists:

Dr. David Evers, Executive Director & Chief Scientist, Biodiversity Institute, Portland, MA

Kevin Kenow, Research Wildlife Biologist, U.S. Geological Survey Upper Midwest Environmental Sciences Center, LaCrosse, WI

Carrol Henderson, former MNDNR Manager, Non-game Wildlife, St. Paul, MN

Kay Rezanka, former biology instructor, Central Lakes College, Brainerd, MN

Amy Rager, Extension Professor, State Dir. MN Master Naturalist, Morris, MN

Kevin McDonald, Supervisor, Business Assistance Unit ,Minnesota Pollution Control Agency, St. Paul, MN

Seth Goreham, West District Manager, Ecological & Water Resources, MN DNR, Brainerd, MN

Dr. Walter H. Piper, Professor Schmid College of Science & Technology, Chapman University, Orange, CA

The following resources provide additional scientific data and information:

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Evers, D.C. , J.D. Paruk, J.W. McIntyre, and J.F. Barr (2010). Common Loon (Gavia immer), version 2.0. In The Birds of North America (A.F. Poole, Editor), Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.313

Gingras, B. A., and C. A. Paszkowski. 2006. Feeding behavior and modeled energetic intake of common loon (Gavia immer) adults and chicks on small lakes with and without fish. Pages 247-261 Limnology and Aquatic Birds. Springer.

Gudger, E. W. 1949. Natural history notes on tiger sharks, (Galeocerdo tigrinus), caught at Key West, Florida, with an emphasis on food and feeding habits. Copeia 1949:39-47.

Jukkala, G., and W. Piper. 2015. Common loon parents defend chicks according to both value and vulnerability. Journal of Avian Biology 46:551-558. Kenow, K.P., Houdek, S.C. , Fara L.J., Gray, B.R., Lubinski B.R., Heard, D.J., Meyer M.W. Fox, T.J.

Kenow, K.P. Houdek, S.C., Fara L>J., Gray, B.R. , Lubinski B.R., Heard, D.J. , Meyer, M.W., Foxm T.J., Krat, R.J. 2018. Distribution and foraging patterns of common loons on Lake Michigan with implications for exposure to type E avian botulism. Journal of Great Lakes Research 44:497-513

Mager, J. N., C. Walcott, and W. H. Piper. 2007. Male common loons, Gavia immer, communicate body mass and condition through dominant frequencies of territorial yodels. Animal Behaviour 73:683-690.

Mager, J. N., C. Walcott, and W. H. Piper. 2012. Male Common Loons Signal Greater Aggressive Motivation By Lengthening Territorial Yodels. The Wilson Journal of Ornithology 124:73-80.

McIntyre, J. W. 1988. The common loon : spirit of northern lakes. University of Minnesota Press, Minneapolis.

Merrill, E. H., J. J. Hartigan, and M. W. Meyer. 2005. Does prey biomass or mercury exposure affect loon chick survival in Wisconsin? The Journal of Wildlife Management 69:57-67.

Nelson, D. H. 1983. A Common Loon nest from New Hampshire containing four eggs. The Wilson Bulletin 95:672-673.

Paruk, J. D. 2006. Testing hypotheses of social gatherings of common loons (Gavia immer). Pages 237-245 Limnology and Aquatic Birds. Springer.

Paruk, J. D. 2008. Nocturnal behavior of the Common Loon (Gavia Immer) The Canadian field-naturalist 122:70-72.

Paruk, J. D., D. Seanfield, and T. Mack. 1999. Bald eagle predation on common loon chick. The Wilson Bulletin 111:115-116.

Piper, W., D. Evers, M. Meyer, K. Tischler, and M. Klich. 2000a. Do common loons mate for life? Scientific investigation of a widespread myth. Loons: Old History and New Findings (Ed. by JW McIntyre & DC Evers):43-49.

Piper, W. H., K. M. Brunk, G. L. Jukkala, E. A. Andrews, S. R. Yund, and N. G. Gould. 2018. Aging male loons make a terminal investment in territory defense. Behavioral Ecology and Sociobiology 72:95.

Piper, W. H., J. A. Grear, and M. W. Meyer. 2012. Juvenile survival in common loons: Effects of natal lake size and pH. Journal of Avian Biology 43:280-288.

Piper, W. H., J. N. Mager, C. Walcott, L. Furey, N. Banfield, A. Reinke, F. Spilker, and J. A. Flory. 2015. Territory settlement in common loons: no footholds but age and assessment are important. Animal Behaviour 104:155-163.

Piper, W. H., M. W. Palmer, N. Banfield, and M. W. Meyer. 2013. Can settlement in natal-like habitat explain maladaptive habitat selection? Proceedings of the Royal Society B: Biological Sciences 280.