Extra-pair paternity in birds: a life-history dilemma?

FERRETTI VALENTINA; MAKAREWICH, C. A.; MASSONI, VIVIANA; ROBINSON, TARA; LILJESTHROM, MARCELA; WINKLER, DAVID W.; LOVETTE, IRBY J.

Ithaca

Congreso; 12th International Behavioral Ecology Congress; 2008

Since 1987 when DNA molecular techniques were first applied to behavioral and ecological studies of mating systems in birds, the long standing assumption that almost 90% of avian taxa are monogamous (Lack 1968) has steadily eroded. Now, it is difficult to speak of avian mating systems without distinguishing between social and genetic mating systems, but we still lack a unified understanding of the causes of variation in extra-pair paternity rates (EPP). Our limited knowledge of this topic may be due to 1) insufficient sampling of EPP rates for taxa with certain life histories (e.g., tropical, southern temperate taxa) and/or 2) inadequate understanding of the links between EPP and other life history traits. Here I present paternity data for swallow species in the genus Tachycineta that breed at different latitudes across the Americas, and show how tropical and southern hemisphere birds have different reproductive strategies than do the better-studied northern hemisphere birds. I further use these data to explore the relationships among various life-history traits (i.e. clutch size, lay date, survival) that might affect the level of EPP.