  Dispersal is ubiquitous throughout the tree of life: factors selecting for
dispersal include kin competition, inbreeding avoidance and spatiotemporal
variation in resources or habitat suitability. These factors differ in whether
they promote male and female dispersal equally strongly, and often selection on
dispersal of one sex depends on how much the other disperses. For example, for
inbreeding avoidance it can be sufficient that one sex disperses away from the
natal site. Attempts to understand sex-specific dispersal evolution have
created a rich body of theoretical literature, which we review here. We
highlight an interesting gap between empirical and theoretical literature. The
former associates different patterns of sex-biased dispersal with mating
systems, such as female-biased dispersal in monogamous birds and male-biased
dispersal in polygynous mammals. The predominant explanation is traceable back
to Greenwood's (1980) ideas of how successful philopatric or dispersing
individuals are at gaining mates or resources required to attract them. Theory,
however, has developed surprisingly independently of these ideas: predominant
ideas in theoretical work track how immigration and emigration change
relatedness patterns and alleviate competition for limiting resources,
typically considered sexually distinct, with breeding sites and fertilisable
females limiting reproductive success for females and males, respectively. We
show that the link between mating system and sex-biased dispersal is far from
resolved: there are studies showing that mating systems matter, but the
oft-stated association between polygyny and male-biased dispersal is not a
straightforward theoretical expectation... (full abstract in the PDF)
