A pair of murres watch over their chick.

The common murre is one of the success stories of the sea – about 10 million breed in the northern parts of the Pacific and Atlantic Oceans, and millions more are young birds that are gaining the experience they’ll need to attempt nesting the first time. Many of the features of murres’ life history show just how difficult life at sea is. Murres don’t even try to breed for the first time until they’re five or six years old and murres lay only one egg in a clutch, probably because the difficulty of finding food means that they are able to feed only one chick. Both parents take turns incubating the egg on a bare rock ledge. Common murres can fly 200 kilometers from the nest to find food for their chicks, and may dive as deep as 100 meters for food, but 70 kilometers and 50 meters are probably more typical maximums. Murres feed their chicks three to five fish a day, and adults eat mostly fish too, but they may also consume zooplankton and squid.

Murres nesting on Duck Island.

One of the most interesting sides of murre biology is that chicks leave the nest before they can fly, and before they’re even half grown. Biologists think this happens because it’s too difficult for murre parents to bring enough fish to the colony the raise a full-grown chick, so the chick finishes growing at sea, where the father looks after the chick and helps feed it for about two months. One of the most beautiful parts of our field season is when the murre chicks leave the nest. At dusk in late August murre fathers congregate on the water below the colonies and call up to their chicks in anxious voices. Soon the chicks begn answering with their shrill calls, and the little downy birds start raining down into the water. The lucky ones jump off the cliff and land in the water, but many others bounce down the rocks on their first trip out of the nest – it’s amazing what those little guys can survive. As for why only the fathers accompany chicks at sea, no one knows for sure!

Varied colors and patterns of Common Murre eggs.