Time-activity budget for common loons, Gavia immer, nesting on Lake Superior

Three pairs of color-marked Common Loons (Gavia immer) nesting on the Lake Superior shoreline of Isle Royale National Park, Michigan, were observed from mid-May to early August of 1992 and 1993 to develop atime-activity budget which could be compared with that of loons nesting on inland lakes elsewhere. Lake Superior loons spent significantly more time moving about their territories during the pre-nesting stage than at any other time during the breeding season and significantly more time resting during the post-nesting stage than at any other time (P< 0.05). We present evidence that the optimal time budget for aloon in its given habitat may be relatively flexible and subject to environmental influence. Differences in loon behavior over time may reflect changing environmental conditions (e.g., changes in the prey base or water quality) and provide valuable information for conservation efforts. [ABSTRACT FROM AUTHOR]