Female philopatry and male-biased dispersal in a direct-developing salamander, Plethodon cinereus

Abstract

The local resource competition hypothesis and the local mate competition hypothesis were developed based on avian and mammalian systems to explain sex-biased dispersal. Most avian species show a female bias in dispersal, ostensibly due to resource defence, and most mammals show a male bias, ostensibly due to male-male competition. These findings confound phylogeny with mating strategy; little is known about sex-biased dispersal in other taxa. Resource defence and male-male competition are both intense in Plethodon cinereus, a direct-developing salamander, so we tested whether sex-biased dispersal in this amphibian is consistent with the local resource competition hypothesis (female-biased) or the local mate competition hypothesis (male-biased). Using fine-scale genetic spatial autocorrelation analyses, we found that females were philopatric, showing significant positive genetic structure in the shortest distance classes, with stronger patterns apparent when only territorial females were tested. Males showed no spatial genetic structure over the shortest distances. Mark-recapture observations of P. cinereus over 5 years were consistent with the genetic data: males dispersed farther than females during natal dispersal and 44% of females were recaptured within 1 m of their juvenile locations. We conclude that, in this population of a direct-developing amphibian, females are philopatric and dispersal is male-biased, consistent with the local mate competition hypothesis.

The ‘male escape hypothesis’: sex-biased metamorphosis in response to climatic drivers in a facultatively paedomorphic amphibian

“…Similarly, in tiger salamanders, paedomorphic males are more philopatric than females to their ponds. The philopatry of one sex is thought to result from the asymmetry in the costs of dispersal, as well as the greater benefits of familiarity with a natal area, resulting in greater acquisition of resources [63,64]. The acquisition of resources of individuals using temporary and permanent ponds, but also of those remaining in water, versus those moving to land, is likely to be very different; therefore, variation across studies may lie in the relative advantages of life in the aquatic and terrestrial environments.…”

How Sex-Biased Dispersal Affects Sexual Conflict over Care

“…By our knowledge, all meta-analyses on the selective causes of sex-differences in parental care focus on birds (Olson et al, 2008;Liker et al, 2013), so we discuss the ramifications of our model below in the context of birds. Nonetheless, we emphasize that evolutionary transitions between female-only, male-only and biparental care also occur in fish, reptiles and amphibians (Goodwin et al, 1998;Balshine, 2012), and given the recent accumulation of studies on sexbiased dispersal in these groups (e.g., Palo et al, 2004;Liebgold et al, 2011;Wang et al, 2012;Hutchings, 2003) assessing the consequences of our model should be a goal of future meta-analyses.…”

Potential reduction in terrestrial salamander ranges associated with Marcellus shale development

“…Modeling steps, from left to right: probability surface to generate new well pad locations, 10,000 well pads, 20,000 well pads, and 50,000 well pads. Liebgold et al, 2011), recovery of populations in disturbed areas is difficult to predict and will be limited in ways that are poorly understood. Legacy effects of Marcellus development on terrestrial salamander populations are potentially varied and still unknown as these drilling methods and policies are new and changing as technology develops.…”

“…Older and interior forests can better maintain these conditions (Ash, 1995), and accordingly, almost all terrestrial plethodontid species in the eastern US reach their peak abundances in mature and old-growth forests (Petranka et al, 1993;Petranka, 1998;Connette and Semlitsch, 2013). These species are typically characterized by sensitivity to microhabitat changes, low fecundity, limited dispersal ability (Liebgold et al, 2011;Ousterhout and Liebgold, 2010), small home range sizes (Sinsch, 1990;Mathis et al, 1995;Stebbins and Cohen, 1995), and high endemism. Even in forested landscapes, plethodontid salamanders are sensitive to water loss, contributing to variation in abundance and distribution over small scales (Peterman and Semlitsch, in press).…”