The Effects Of Environmental Variability And Latitude On Breeding Behaviors and Life History Traits Of Aves In North America

Breeding systems among Aves have garnered attention in the last several decades as many species considered monogamous have been found to exhibit an alternative breeding system such as polygyny, polyandry, cooperative breeding, or colonial nesting. My thesis focuses on assessing the correlations between type of breeding system and resource availability by using environmental variables as proxy variables. It also assess the correlations between life history trait variables and environmental variables. Both breeding system and life history traits are analyzed at the species and population levels while controlling for phylogenetic relationships and geographic location when appropriate. Breeding system among species was not significantly influenced by environmental variables or latitude. Breeding system within species was significantly influenced by environmental variables for the House Wren (Troglodytes aedon) for the variables mean annual temperature and mean temperature during the driest quarter. Life history traits among species were significantly correlated to environmental variables for clutch size and fledging but not for parental care. Life history traits within species were significantly correlated to environmental variables for the Bewick’s wren (Thryomanes bewickii) and marginally significantly correlated to environmental variables for the Brown-headed Nuthatch (Sitta pusilla) when geographic distance between populations was controlled.