Polyandry in a marine turtle: Females make the best of a bad job

Abstract

The female perspective on reproductive strategies remains one of the most active areas of debate in biology. Even though a single mating is often sufficient to satisfy the fertilization needs of most females and the act of further mating incurs costs, multiple paternity within broods or clutches is a common observation in nature. Direct or indirect advantage to females is the most popular explanation. However, the ubiquity of this explanation is being challenged by an increasing number of cases for which benefits are not evident. For the first time, we test possible fitness correlates of multiple paternity in a marine turtle, an organism that has long attracted attention in this area of research. Contrary to the widespread assumption that multiple mating by female marine turtles confers fitness benefits, none were apparent. In this study, the environment played a far stronger role in determining the success of clutches than whether paternity had been single or multiple. A more likely explanation for observations of multiply sired clutches in marine turtles is that these are successful outcomes of male coercion, where females have conceded to superfluous matings as a compromise. Thus, multiple matings by female marine turtles may be a form of damage control as females attempt to make the best of a bad job in response to male harassment.

Polyandry pays off: The effects of multiple mating and number of fathers on morphological traits and survival in clutches of nesting green turtles at Tortuguero

“…Hence, we found no evidence of improved fitness in the offspring when sired by a primary father (male who gives greater proportion of the offspring) compared to any other secondary fathers. Similar results were concluded in Lee and Hays (2004) study.…”

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“…Hence, we found 392 no evidence of improved fitness in the offspring when sired by a primary father (male who gives 393 greater proportion of the offspring) compared to any other secondary fathers. Similar results were 394 concluded in Lee and Hays (2004) study. 395 In this study, measurements of morphological traits (crawling speed, length and weight) were taken 396 following the same procedure.…”

“…While some 41 authors have argued that its prevalence is intriguing, due to the energetic fitness costs that such 42 behaviour incurs (Lee & Hays, 2004;Bilde et al, 2009), others have demonstrated how females may 43 gain indirect genetic benefits to offset the cost by mating with multiple males (Byrne & Roberts, 2000; 44 LaBrecque et al, 2014). For example, polyandry may provide genetic benefits by improving the 45 chance that females will acquire "good" genes or by enhancing the genetic diversity of their progeny 46 (Yasui, 1997 (Packer et al, 1991;Craighead et al, 1995;Keane, Dittus & Melnick, 1997;FitzSimmons, 1998; Uller 51 & Olsson, 2008) and enabling investigation into the genetic consequences of multiple matings.…”

“…In a previous study from 90 Ascension Island in the middle Atlantic, the fitness in clutches was found to be not correlated with the PrePrints 93 authors of this study did not measure direct physical or morphological traits in the hatchlings. In the 94 present study, most measures from the Lee & Hays (2004) study were included in the analysis. 95 Moreover, in addition we expanded by including measures of morphological traits of offspring survival 96 measured by the emergence success; weight, length and crawling speed in order to generate additional 97 parameters that may provide a more detail insight into the offspring fitness.…”

Condition dependence of reproductive strategy and the benefits of polyandry in a viviparous lizard

“…Confronted with the potential costs of multiple mating, the risk of disease transmission, predation, energetic loss and costs resulting from harmful male adaptations (Andersson 1994;Byrne & Roberts 1999;Thrall et al 2000), many hypotheses have been proposed to explain why females mate multiply (Reynolds 1996;Jennions & Petrie 2000;Eberhard & Cordero 2003). First, these females may not retain complete control over mating or they may avoid the cost of resistance to male harassment (Thornhill 1980;Lee & Hays 2004). Second, females may obtain direct benefits from multiple mating, which extends from the supply of sufficient fertile sperm (assurance of fertilization; Sheldon 1994) to any form of paternal investment, such as parental care, nuptial gifts or sperm nutrients (Davies 1992;Andersson 1994).…”