Influences on male reproductive success in long-lived Blanding's Turtles (Emydoidea blandingii)

Abstract

Knowing how the number and qualities of mates influence male reproductive success (RS) can help interpret mating system dynamics that are important for conservation efforts. We combined parentage data (1999-2006) with data from a long-term life history study (1953-2007) of Blanding's Turtles (Emydoidea blandingii, Holbrook 1838) on the University of Michigan's E. S. George Reserve to document the relative influence of mate number and quality on male RS. Blood samples were taken from > 92% of resident adults and tissue samples were taken from 723 hatchlings from 92 nests of 54 females over 8 nesting seasons. The incidence of multiple paternity averaged 41.6% (N = 77), was variable among years (min-max = 15.4-55.6%), and was positively associated with female age, body size, and clutch size. Repeat paternity was observed in 69.9% of sequential clutches of the same female separated by 1-7 years. Male RS was variable (1-40 offspring) and was positively associated with the number of mates and clutches sired. The youngest male to sire offspring was 22 years old. Adult movements that result in encountering different mates and/or the ability to use attributes (e.g., size or age) to identify high-quality mates have the potential to substantially increase RS.