Uria aalgecommon murre(Also: guillemot;common murre)

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Geographic Range

During breeding, the common murre populations of the Pacific Ocean range from coastal areas of western Alaska to central California. The Atlantic Ocean populations range from Labrador to Nova Scotia. They spend the winters close to the breeding areas but their range extends to southern California in the Pacific populations and to Maine in the Atlantic populations.

(del Hoyo, et al. 1996, Ehrlich 1988)

Habitat

The common murre is primarily a pelagic species. It spends the majority of its time at sea except for during breeding season. The breeding season is spent on costal cliffs or offshore islands that are primarily rocky. (Ehrlich 1988, del Hoyo, et al. 1996, Terres 1980)

Physical Description

At first glance, the common murre appears penguin-like, as the breeding adults are dark brown-black on the head, neck and back with a white underbelly and white tipped secondary feathers. They are about 38-43cm in length and stand upright like a penguin when on land. They have dark, long, and slender bills and dark greyish-black feet and legs. They have a wingspan of 64-71 cm. The adult winter plumage is mostly identical except for white on the cheeks and throat and a dark spur extending back from the eye. An alternate form, or the bridled morph, only occurs in a population in the North Atlantic. It has an eye ring with a line extending toward the back of its head in addition to the regular adult plumage. Chicks are downy when first hatched. They are blackish brown on top and white underneath. When they are first hatched they weigh 55-95 grams. Juveniles are similar to adults except for their smaller size and darker heads.

(Ehrlich 1988, del Hoyo, et al. 1996, Terres 1980)

  • Range mass
    945 to 1044 g
    33.30 to 36.79 oz
  • Average basal metabolic rate
    6.8224 W
    AnAge

Reproduction

The first breeding season takes place at the age of 4-6 years. The common murre does not use nesting material, as the one egg is laid on the bare rock or soil of a steep cliff or ledge facing the sea. The egg is pyriform or pear-shaped which prevents it from rolling off of the ledge. This is because the egg pivots around the pointed tip when it is disturbed. The shape also maximizes the amount of surface area that will be in contact with the parent's brood patch during incubation. Eggs are laid between May and July in populations breeding on the Atlantic coast and between March and July on the Pacific coast. The eggs vary in colour from pure white to shades of green, blue, or brown with spots or speckles of brown, lilac, or black. These various colour forms are important for egg recognition by parents. Both parents participate in the incubation process, which takes between 28 and 34 days and is divided into 12-24 hour shifts. Chicks of the common murre are semiprecocial. Chicks fledge (leave the nest) at 18-25 days and go out to sea with the male of the pair. The chick is able to fly at the age of 39-46 days. (Ehrlich 1988, del Hoyo, et al. 1996, Terres 1980)

  • Average eggs per season
    1
    AnAge
  • Average time to hatching
    31 days
    AnAge

Lifespan/Longevity

Behavior

The common murre nests in large colonies (called a loomery) on rocky offshore islands of the sea. Often these islands have numerous other bird species nesting there including puffins, guillemots, kittiwakes, gulls, storm petrels, and razorbills. These islands usually have stratification for nesting sites. Murres are usually found on the cliff ledges of the upper half of the cliff, below puffins and gulls but above kittiwakes and guillemots. The common murre is monogamous and they exhibit a high degree of site and mate fidelity. Pairs arrive several weeks before eggs are laid and they participate in courtship displays including, mutual bowing, billing and preening. The male often throws his head back and points his bill vertically in a display to the female. The colonies are usually so dense that as many as 20 pairs may be incubating in an area of only 1 square meter. If an egg is lost early on it can be replaced in 14-16 days. The main reasons for egg loss are mishandling by the adult and some occurs as a result of gull predation. Both adults of a pair care for the chick before it is fledged. Often, to prevent young chicks from jumping off the ledge before they should, adults will stand between the chicks and the cliff edge. When the chick leaves the nest it leaps off and flutters down to the sea, a drop of 800-1500 feet. The male of the pair then escorts out the chick to sea, where he feeds and cares for it until it is able to fly on its own. For up to 2 weeks after the chick is fledged, the female remains at the breeding site.

The murre flies strongly using steady wing beats. They are fast direct fliers and exhibit considerable agility when feeding, by frequently turning from side to side. Usually they fly close to the water when they are feeding or are around the breeding grounds. For long distances, the common murre travels in large flocks high in the air. As a result of its small wing size and relatively heavy body, it must run along the water surface to obtain enough speed to achieve lift and take flight.

The main vocalization of the common murre is a soft purring. On the breeding grounds, croaks, growls and moans are also made. (Ehrlich 1988, del Hoyo, et al. 1996, Terres 1980)

Communication and Perception

Food Habits

The common murre is mainly piscivorous. They are surface divers that can remain submerged for up to one minute at a time. They often dive to a depth of 100 feet but have been recorded to reach a depth of 550 feet. They use their strong wings to fly underwater. Adults consume between 20g and 32g of food everyday. They mostly catch small fish up to 7 inches in length, which they carry in their bills lengthwise with the tail hanging out. Most of the fish species consumed include polar cod, capelin (Mallotus), launces, sprat (Sprattus), sandeels (Ammodytes), small Atlantic cod and herring (Clupeus). They also eat a variety of marine worms, amphipods, shrimp, molluscs, and Arctic squids.

(Ehrlich 1988, del Hoyo, et al. 1996, Terres 1980)

Economic Importance for Humans: Positive

The excrement of the common murre is rich in potash, which is important for the growth of many marine species. Many of these species are essential food sources for a variety of fish species which have economic uses by humans.

(Terres 1980)

Economic Importance for Humans: Negative

Unknown.

Conservation Status

Although the common murre is not threatened, they are highly susceptible to the damaging effects of oil spills and pollution.

(Terres 1980)

Contributors

Jody Bennett (author), University of Alberta, Cindy Paszkowski (editor), University of Alberta.

Glossary

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

visual

uses sight to communicate

References

Ehrlich, P. 1988. The Birder's Handbook: a Field guide to the Natural History of North American Birds. New York: Simon & Schuster.

Terres, J. 1980. The Audubon Society Encyclopedia of North American Birds. New York: Random House.

del Hoyo, J., A. Elliott, J. Sargatal, eds. 1996. Handbook of the Birds of the World. Vol. 3. Hoatzin to Auks. Barcelona: Lynx Edicions.