Post-fledging Survival of Marbled Murrelets Brachyramphus Marmoratus Estimated

Post-fledging juvenile survival rates are difficult to measure, particularly for seabirds (Harris et al. 1994, Gaston 1997). However, several studies have highlighted the demographic importance of estimates of survival during the first year, and until first breeding, for both seabirds (e.g. Hudson 1985) and birds in general (e.g. Ganey et al. 1998, Hafner et al. 1998). Such estimates are particularly important in the construction of population projection models (e.g. Caswell 2001). Commonly used in studies with conservation implications, these models provide a standard analytical tool for estimating population growth rates as well as assessing the possible consequences of changes in various demographic parameters to these rates.