Annual and seasonal survival of Orange-crowned Warblers breeding on the Channel Islands.

T. S. SILLETT; S. I. PELUC; J. YOON ; C. K. GHALAMBOR

Laramie, Wyoming,

Congreso; 125th Stated Meeting of the American Ornithologists' Union.; 2007

Statistically rigorous population studies of passerine birds require several years of data because of interannual variation in weather and avian demographic rates. Here, we present a mark-recapture analysis of 5 yr survivorship data for Orange-crowned Warblers (Vermivora celata sordida) breeding on Catalina Island, California. Annual rainfall varies dramatically on the Channel Islands, due in part to forcing from the El Niño Southern Oscillation. Annual survival of warblers on Catalina Island covaried with annual rainfall from 2003 - 2007, being lower in dry years and higher in wet years. However, survival during the breeding season did not vary strongly with rainfall. Our results suggest that V. c. sordida populations could be at risk from predicted drying and shifts in rainfall regime on the Channel Islands due to climate change.