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Loons are water birds like ducks, geese, and grebes, but they
are classified separately by scientists. The five species are: |
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Red-throated Loon -- Gavia stellata |
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Pacific Loon -- Gavia pacifica |
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Arctic Loon -- Gavia arctica |
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Yellow-billed Loon -- Gavia adamsii |
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Common Loon -- Gavia immer |
| The Common Loon is the species best known to most of us, as its
breeding range lies across most of Canada. All five species of
loons migrate to warmer areas around the Gulf of Mexico and on
the east and west coasts of North America to winter, and return
to northern lakes to breed when the ice melts in spring. |
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| Common Loon |
| Body Form and Plumage |
| The Common Loon in summer is very striking with its black-and-white
checkered back, glossy black head, white belly and wing lining,
and characteristic white necklace around the throat. All loons
have grayish feathers in the winter, and immature birds tend to
resemble adult birds in winter plumage. The white feathers of
the belly and wing lining are present year-round. |
| Loons' habit of swimming low in the water helps to distinguish
them from other waterbirds, such as ducks and geese. Loons most
resemble the grebes, but can be identified by their larger size,
thicker necks, and longer bills. In flight, loons can be recognized
by their humpbacked profile, with head and neck held low and feet
pressed back towards the body and projecting beyond the tail. |
| Both males and females look the same, although males are generally
larger. Adults are large-bodied, weighing from 2.7 to over 6.3
kg and measuring almost a metre from bill tip to outstretched
feet. The bill is quite large, averaging 75 mm in length, and
is black in colour throughout the year. |
| The skeleton and muscular system are designed for swimming and
diving. Loons are streamlined. Their legs are placed far back
on their body, allowing for excellent movement in water but making
them ungainly on land. The head can be held directly in line with
the neck during diving to reduce drag, and the legs have powerful
muscles for swimming. Many bones of the loon's body are solid,
rather than hollow like other birds', aiding in diving ability.
During dives, the large webbed feet provide all of the propulsion
and the wings are held tight unless they are used to help make
sharp turns while chasing prey. |
| Daily Life |
| Loons spend their time hunting, feeding, resting, preening, and
caring for young. They are predators; their diet in summer consists
of fish, crayfish, frogs, snails, salamanders, and leeches. Adult
loons prefer fish to other food, and seem to favour perch, suckers,
catfish, sunfish, smelt, and minnows. The life expectancy of the
loon may be 15-30 years. |
| The bird spends long rest periods motionless on the water. It
may rouse itself to stretch a leg or wing at intervals, occasionally
comically waggling a foot. When swimming on top of the water it
will sit erect with neck slightly curved. The loon will peer underwater,
moving its head from side to side to locate prey. It then aims
and dives quickly. It will stay underwater for almost a minute
and can dive to depths of 80 m. During the dive, feathers are
compressed and air is forced from between the feathers and from
the air sacs in the body. Loss of air from the air sacs also allows
the loon to quietly sink below the water surface to avoid danger. |
| Adult loons may fly to different lakes to feed. The adaptations
that make loons such efficient divers also make them heavy and
slow to take wing. To take off from a lake, loons run along the
surface into the wind. The distance needed to gain flight depends
on wind speed; in calm times the birds may run as far as several
hundred meters before they gain enough speed to take off. Once
in the air, the loon's relatively small wingspan (130-140 cm)
carries it at average speeds of 120 km per hour during migration.
The wings beat quickly to carry the large body and have a high
degree of curvature to provide lift. |
| Common Loons spend little time on land and have to pull themselves
onto land to nest. They generally move one foot at a time to walk,
shuffling along with their breast close to the ground. On return
to the water, the loon slides in along its breast and stomach.
At night, loons sleep over deeper water, away from land for protection
from predators |
| Family and Social Life |
| Loons arrive in pairs on northern lakes in the spring as soon
as the ice thaws. Loons are solitary nesters. Small lakes, generally
those between 5 and 50 ha, can accommodate one pair of loons.
Larger lakes may have more than one pair of breeding loons, with
each pair occupying a bay or section of the lake. Until recently,
loons were thought to mate for life. Banding studies have shown
that loons will sometimes switch mates after a failed nesting
attempt, even between nestings in the same season. Courtship and
mating are a quiet time, with the pair swimming and making short
dives together. Eventually the male leads the female to a suitable
spot on land for copulation. Nest building then begins |
| Loons build their nests close to the water, with the best sites
being completely surrounded by water, such as on an island, muskrat
house, half-submerged log, or sedge mat. Generally the birds can
slip directly from the nest to water. The same sites are often
used from year to year. Loons will use whatever materials are
on hand to build their nests: tree needles, leaves, grass, moss,
and other vegetation have been found under loon eggs. If material
is not handy, loons will lay their eggs directly on the mud or
rock substrate. Sometimes clumps of mud and vegetation are collected
from the lake bottom to build the nest. Both the male and female
help in nest building and with incubation, which lasts until hatching,
usually 26-31 days. If the eggs are lost, the pair may renest,
often in the same general location. |
Usually two eggs are laid in June, and towards the end of the
month loon chicks covered in brown-black down appear on the water.
Loon chicks can swim right away, but spend some time on their
parents' backs to rest, conserve heat, and avoid predators such
as large carnivorous fish, snapping turtles, gulls, eagles, and
crows. After their first day or two in the water, the chicks do
not return to the nest.
Chicks are fed exclusively by their parents for the first few
weeks of life, and up until eight weeks of age the adults are
with them most of the time, providing most food. After this time
the chicks begin to dive for some of their own food and by 11
or 12 weeks of age, the chicks are providing almost all of their
own food and may be able to fly. Chicks are fed small food items
early in their life including snails, small fish, crayfish, minnows,
and some aquatic vegetation. As they grow, they require more protein,
and usually are fed more fish, if available. At migration time,
the young are able to look after themselves, and the adults generally
leave first, with young following soon after. |
| Sometimes loons gather into small groups in the summer. In September,
group feeding is quite common as loons gather on larger lakes
while migrating. Loons are also usually found in groups on the
wintering grounds. |
| The Voice of the Loon |
| Perhaps one of the most fascinating things about Common Loons
is their haunting and variable voice. Loons are most vocal from
mid-May to mid-June. They have four distinct calls which they
use in varying combinations to communicate with their families
and other loons. These are the tremolo, wail, yodel, and hoot.
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| The tremolo sounds like a crazy laugh and is used for a variety of purposes,
such as to signal alarm or worry and to denote annoyance or greeting. |
| The wail is one of the loveliest of loon calls. It is used frequently
during social interactions between loons and may be used to regain
contact with a mate during night chorusing and in answering other
loon tremolos. |
| The yodel is given only by the male. It is a long, rising call with repetitive
notes in the middle and can last up to six seconds. It is used
by the male to defend territory and can be stimulated by another
male entering a loon's territory. Studies of recordings have shown
that the yodel is different for each bird and can be used to identify
individual loons. |
| The hoot is a one-note call that sounds more like “hoo.” It is mainly
used by family members to locate each other and check on their
well-being. |
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| This article is an excerpt from the North American Loon Fund website,
however, the article is no longer available online. To find out
more about loons click on the link to the NALF website.
The photograph is from the Environment Canada website. |
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