Meeting Abstract

P1.110  Jan. 4  Clutch Size Variation in the Sulidae: Latitude or Phylogeny? DANIEL, C*; HAUBER, ME; University of Auckland, New Zealand cdan011@ec.auckland.ac.nz

The ecological factors responsible for the positive correlation between clutch size and latitude has received a lot of attention in the recent literature, with studies featuring mostly small passerine birds. A large-scale analysis of these relationships has not yet been attempted in seabirds such as the Pelecaniformes. This study analyzes the contributions of phylogeny and latitude to the variation in clutch size in the order Pelecaniformes, with particular emphasis on the families Sulidae (boobies and gannets) and Phalacrocoracidae (cormorants and shags). Clear phylogenetic patterns were seen in the Sulidae, and to a lesser extent in the Phalacrocoracidae and Pelecaniformes. There was no significant correlation between latitude (range) and clutch size (p=0.14), suggesting that the phylogenetic contribution is more important in this order. The relationships between clutch size, obligate brood reduction and phylogeny, as well as the significance of clutch manipulation experiments in the gannets (Morus sp.) are also discussed.