Female reproductive qualities affect male painted turtle (Chrysemys picta marginata) reproductive success

Abstract

Male reproductive success (RS) in polygamous species with minimal social systems is often determined by the number of mates. However, because male RS is translated through females, the number of offspring sired can also be influenced by female qualities. Empirically sufficient data to document how tradeoffs between mate number and quality influence male RS are seldom available for long-lived, iteroparous species. We combined long-term life history data on the E. S. George Reserve (ESGR, MI, USA) with parentage data from 155 clutches of 59 female painted turtles (Chrysemys picta marginata) of varying reproductive frequencies (2003)(2004)(2005)(2006) to determine the relative contribution of female numbers and qualities on male RS. One previously documented trait of female painted turtles that can have substantial influences on male RS is repeat paternity through the use of stored sperm to fertilize over 95 % of within-year clutches. In addition, our study found that second-clutch producing female painted turtles on the ESGR have higher among-year reproductive frequencies than do first-clutch only females. Multiple paternity was detected in 14.1 % of clutches (min-max=6.1-30.0 % annually), and the number of mates of both sexes was low annually (males 1.0; females 1.2) and over 4 years (males 1.1; females 1.7). Among successful males, RS varied substantially (1-32 offspring) and was strongly influenced by the combination of female reproductive frequency and repeat paternity (>38 % among years), but not mate number. Low mate number for both sexes was unexpected in a species without complex mating behaviors or parental care.

Social network analysis of mating patterns in American black bears (Ursus americanus)

“…That is, males and females of mated pairs are closer in age than unmated pairs. Age-assortative mating can result from males preferentially competing for old (large) high-quality females that may convey high reproductive success to males through more numerous or higher quality offspring (Webster et al 1995;McGuire et al 2014) or because older animals can preferentially acquire and retain occupancy of highquality territories and therefore are more likely to come into contact with one another (e.g. Ferrer & Penteriani 2003).…”

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

“…A comparison between Blanding's Turtle and Midland Painted Turtles supports the prediction that the effect of female quality (specifically reproductive frequency combined with repeat paternity) would be higher in species where females produce multiple clutches per year relative to species that produce a maximum of one clutch per season (McGuire et al 2014). Some female painted turtles produce more than one clutch within a season that are almost always sired by the same male, resulting in substantial increases to a male's RS stemming specifically from the increased reproductive frequency of females McGuire et al 2011McGuire et al , 2014. In Blanding's Turtles, the number of clutches sired was a substantial source of variation in male RS, but was achieved through increasing mate number or through increased reproductive frequencies of the females whom he sired offspring with (or a combination of both).…”

“…The 41.6% overall incidence of MP in clutches of female Blanding's Turtles on the ESGR was similar to one other population of Blanding's Turtles in Scott County, Minnesota (56.3%; Refsnider 2009), but higher than the 8% observed in a 4-year study of a small population in northern Illinois (Anthonysamy 2012). The proportion of clutches with MP in the ESGR and Minnesota populations of Blanding's Turtles was higher than found in other freshwater turtle populations (Western Painted Turtles, Chrysemys picta belli (Gray, 1830): 10.7%-33% (Pearse et al 2002); Midland Painted Turtle, Chrysemys picta marginata Agassiz, 1857: 6.0%-30.0% (McGuire et al 2014)). In the European Pond Turtle (Emys orbicularis (L., 1758)), Roques et al (2006) estimated the incidence of MP to be 10%; however, their estimate of MP was more conservative (i.e., it was based on three or more paternal alleles in more than four loci) than the methods used to quantify MP in painted turtles (based on three or more paternal alleles in any locus; Pearse et al 2002;McGuire et al 2014) or more than one male identified through parentage assignment (McGuire et al 2014).…”

“…However, even in species with minimal social organization, female qualities can also have a substantial influence on male RS (Altmann 1997;Craig et al 2002;Wong and Svensson 2009;Zhang et al 2010;McGuire et al 2011McGuire et al , 2014. Spatial or temporal variation in the number and qualities of reproductive females can alter the relative importance of mate number and quality on male RS (Emlen and Oring 1977;Gross 1996;Dreiss et al 2010;McGuire et al 2014). Therefore, documenting the conditions that influence the relative importance of mate number and mate quality to male RS requires detailed knowledge of reproductive histories and reproductive qualities of females that often require data from long-term lifehistory studies to understand mating systems of long-lived iteroparous species, such as turtles (McGuire et al 2011).…”

“…Mating-system studies conducted in conjunction with long-term studies of freshwater turtles are rare, but the few that exist have provided new perspectives on the relative contributions of mate numbers versus mate qualities on male RS Pearse et al , 2002McGuire et al 2011McGuire et al , 2014, and can be important for developing conservation and management plans (McGuire et al 2013). For example, aspects of the mating system can influence the effective population size, levels of spatial-genetic structuring, and population-and cohort-specific coancestry (Nunney 1993;Scribner et al 1993;Miller et al 2009;Pearse and Anderson 2009).…”