The Relationship between Deferred Breeding and Mortality in the Laysan Albatross

The dynamics of the Laysan Albatross show agreement with the concepts associated with delayed breeding in the following ways: (1) young birds do not first breed in significant numbers until the age of 8 or 9 years, (2) they nest later than experienced breeders in their first 2 or 3 years, (3) chicks hatched from eggs laid late in the season are subject to much greater mortality than those from earlier eggs laid by experienced breeders, and (4) young breeders fledge relatively few chicks in their first 2 years of breeding. The generally increased mortality postulated as occurring when birds initiate breeding at ages younger than usual for the species is not found in the Laysan Albatross. Higher mortality rates occur only in the 3rd to 6th years of breeding, without sexual difference and without significant relationship to the age at which breeding began. Nonetheless, evidence shows that Laysans that initiate reproduction 2 years earlier or 1 or 2 years later than normal may not survive as long.