Chapter 9: Molts and Plumages in the Annual Cycle of the Marbled Murrelet

Abstract

Marbled Murrelets have distinct basic, alternate and juvenal plumages. In after-hatching-year (adult) birds, the incomplete pre-alternate molt occurs rapidly over a period of about one month per individual between late February and mid-May. The complete pre-basic molt occurs between mid-July and December. At this time, individuals are flightless for about two months. In late summer, it is difficult to distinguish adult birds undergoing prebasic molt from juveniles at sea. Field methods for separating these age categories at sea at this time of the year are presented. By early fall, older juveniles are not distinguishable in the field from after-hatching-year birds in basic plumage. The timing of prebasic and pre-alternate molts were closely related to the timing of breeding, movements and other aspects of the annual cycle of Marbled Murrelets in Barkley Sound, British Columbia.

Parent Publication

• Ecology and conservation of the Marbled Murrelet

Citation

Carter, Harry R.; Stein, Janet L. 1995. Chapter 9: Molts and Plumages in the Annual Cycle of the Marbled Murrelet. In: Ralph, C. John; Hunt, George L., Jr.; Raphael, Martin G.; Piatt, John F., Technical Editors. 1995. Ecology and conservation of the Marbled Murrelet. Gen. Tech. Rep. PSW-GTR-152. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; p. 99-112