With an estimated world population of 22 million, the Thick-billed Murre, Uria lomvia, is probably even more numerous than the Common Murre. Large numbers of Thick-billed Murres breed within the Arctic Circle and remain year round in areas where there is some sea ice.
The Northern Equivalent of the Penguin
Murres are auks, or alcids, a group that also includes murrelets, auklets, puffins, razorbills, guillemots, and dovekies. Though smaller than most penguin species, murres have much in common with them. They:
- eat fish, small crustaceans and other small ocean creatures found in abundance on continental shelves. They sometimes range long distances from the colony in search of food.
- have very dark or black backs and white breasts: the black makes them difficult to see against the dark water from above, while the white helps them blend in with the surface from below.
- have small wings and are awkward on land, but have exceptional swimming ability. Murres can fly, but if they were larger, they wouldn’t be able to.
- gather in large noisy colonies each year to breed, always returning to the same place.
Life Cycle of a Thick-billed Murre
Murres can live more than twenty years, hunting for fish in northern waters and breeding on sea cliffs:
- Murre adults begin to breed at two to three years of age; they stay with the same mate and return to the same colony year after year.
- The female lays one egg on a sea cliff ledge without building a nest.
- Both parents take turns tending the egg, which hatches in just over a month. Then the parents take turns tending and feeding the chick.
- After the chick leaves the cliff at about three weeks of age, the father feeds it and teaches it to fish on its own for a month or more.
Interesting Facts About Thick-billed Murres
The Thick-billed Murre is an unusual bird in a number of ways:
- Eggs are laid on narrow rock shelves – the young leave before they are able to fly, gliding down from cliffs on immature wings.
- The male parent moults while caring for the fledgling in the water. Both are flightless as they begin a swimming migration that may span enormous distances. The birds probably swim the first 1600 km (1000 miles).
- The deepest recorded dive of a Thick-billed Murre reached a depth of 210 metres (690 feet). The birds can move at a speed of 2 metres per second (6.5 feet) under water.
- Diving birds can stay under water for up to three minutes.
- Though the Thick-billed Murre is not usually considered a game bird, humans have hunted the species for food for thousands of years.
The Thick-billed Murre is not threatened but it is thought to be declining for various reasons including hunting. In the future, conservation efforts may be necessary.
Related Content:
Sources:
"Bird Fact Sheets: Murres." Hinterland Who’s Who.
Firefly Encyclopedia of Birds. Perrins, Christopher ed. Buffalo: Firefly Books, 2003
Sea & Coastal Birds of North America. Leslie, Scott. Toronto: Key Porter, 2008.
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