Bird Lore: Marbled Murrelet

733
0

marbled_murreletThe seabird that is also a forest bird. That is the Marbled Murrelet, a member of the alcid family that includes murrelets, murres, guillemots and puffins. All of these North American seabirds nest on rocky, offshore islets along the Pacific Coast. Not so the Marbled Murrelet. At some point in its evolutionary past, it discovered that the tops of ancient conifers were perfect for its nests. The nesting location of this species was a bird science mystery until 1974, when a tree climber found the first nest atop on old-growth Redwood in central California’s Big Basin State Park. As it does not nest in any other habitat, the survival of this species became one more reason to protect ancient forests.

The Marbled Murrelet is unique among seabirds because its plumage has evolved to provide camouflage at sea and camouflage in forests. As with most seabirds, during its non-breeding season (winter), the Marbled Murrelet has whitish undersides so that it can not be seen well from below the water’s surface. During nesting season it is a reddish-brown with a marbling of white spots to blend in with the trees when seen from above.

Fish and crustaceans make up most of the Marbled Murrelet’s diet. It eats fish that are small, up to 5 inches in length, such as sand lance, capelin and herring. It forages while swimming underwater, mostly feeding in near-shore waters less than 100 feet deep. If you are familiar with the profile of the Marbled Murrelet, you can sometimes notice it on the surface from the public pier or other points along the Edmonds waterfront. This species is usually seen in ones or two. LeRoy recently photographed this bird in its breeding plumage from the pier.

The nest site is in old-growth forest, either along the coast or up to 15 miles inland. It is up to 150 feet above the ground. A Marbled Murrelet pair has one egg, which is mottled in color to protect it from predation. Both sexes incubate the egg for about a month. The adult birds only return to the nest during the low-light hours just before sunrise and just after sunset. If they are incubating the egg, this is when they rotate on or off the nest. If they are feeding their nestling, this is when they return with food. The use of low-light hours is another evolutionary trait that protects this species when it is away from the sea. After remaining in its nest for about a month, the young bird flies directly to the sea. After the young bird fledges, sometimes the family of three will be seen together on the saltwater.

The flight calls of two Marbled Murrelets can be heard here: http://www.xeno-canto.org/233926.

— By Carol Riddell

Carol Riddell manages the bird education displays, on behalf of Pilchuck Audubon Society and Edmonds Parks & Recreation, at the Olympic Beach Visitor Station.

LEAVE A REPLY

Please enter your comment!
Please enter your name here