Wildlife Spotlight: Common Murre (Uria aalge)

By Peter Winch
Published: February 2007

Common murres in the ocean. Credit: NOAA

Often described as “flying penguins” or “footballs”, common murres are the most abundant bird in the Gulf of the Farallones National Marine Sanctuary.  Every winter these hearty seabirds return to the sanctuary to prospect (scout) for nests.

Common murres belong to the Alcid Seabird family, which includes Puffins and Auklets.  Their breeding plumage, which lasts from December through August, is a distinctive charcoal-black and white.  They have thin black bills and short stubby wings, and are about fourteen inches in length. 

Murres are amazing swimmers and divers, using their strong wings to attain depths of up to 100 meters (300 feet) to forage for food. They feed on cod, capelin, sprat, sand eels, herring, marine worms, amphipods, shrimp and mollusks.

Nesting

Common murres arrive on the Farallon Islands in late fall and begin their nest prospecting.  Breeders normally return to the same site each year, and males and females will stay with each other for many years.

“It is especially important to avoid disturbing the murres during the prospecting and nesting period,” says Karen Reyna, manager of the Seabird Colony Protection Program with the Gulf of the Farallones National Marine Sanctuary. “If the murres are disturbed by watercraft or low-flying aircraft, they may abandon their breeding site altogether.”

In April, a single pear-shaped egg is laid.  The shape is an adaptation to prevent the egg from rolling out of its nest, which is often perched high on a rocky ledge.  Males and females spend equal time incubating the egg.  Chicks hatch in June and are fed three to five fish a day for three weeks.  The hatchlings then literally leap off their precipitous cliff nest into the ocean in response to the adult males calling from the sea below.

The chicks are now officially fledged and begin their life on the ocean.  The fathers do all the parenting, and throughout the summer the fathers can be seen with their chicks, showing them how to forage and be safe in the marine environment.  During the summer they remain closer to shore where the best food supply is.

Murres migrate offshore in September and October and live entirely at sea until they are ready to return to start nest prospecting again.

History

Before the 1850’s the common murre population out at the Farallones was estimated at 400,000 to 500.000.  However, the California Gold Rush of 1849 brought a massive influx of human population to the Bay Area.  This created a fundamental lack of basic raw materials, one of which included eggs.  There were no chickens or chicken farms.  As a result, an extensive murre egging industry developed at the Farallones.

The eggers took millions of eggs over a forty year period, which reduced the common murre population down to 5,000.  There were rival egging gangs (people were killed over eggs), and certain individuals made a fortune.

The murre population has increased steadily, especially since the island was made a refuge in 1969, and is now at its highest since the egging era.  Last year, there were 170,000 murres counted out at South East Farallon Island.  It is estimated there are at least 10 million in the northern parts of the Pacific and Atlantic.

Come See the Murres

FMSA’s whale watching trip on April 29th will be a great opportunity to view this awesome seabird at its peak population out at the islands.