Sneaking from a female perspective

Alternative male mating tactics in species with external fertilization are often viewed as coercive matings by low-quality males, when a male, unable to attract a female himself, steals fertilizations from a spawning pair by adopting ‘sneaky’ mating tactics, thereby eroding the interests of both the pair-mating male and female. Although a cost of sneaking to guarder males is inevitable, we highlight emerging evidence that females may actually seek and benefit from mating with sneaking males. Sneaking may thus be a means by which females gain access to resources critical for reproduction when these are defended by males adopting a guarder tactic, while maintaining some control over indirect (genetic) benefits through mate choice. We consider a range of potential costs and benefits that females may obtain from matings that involve sneakers and review empirical studies on female responses to sneaking. We show that the outcome of the trade-off between costs and benefits is context specific and may vary among mating systems, species, populations within species, and individual females within populations. This emerging evidence undermines the view that sneaking necessarily represents forced fertilizations and that sneakers are always low-quality males making ‘the best of a bad job’. When females prefer to spawn in the presence of sneaker males, the distinction between deliberate polyandry and sneaking becomes ambiguous and females may only be limited in the expression of their mating preferences by resource monopolization or mate guarding by dominant males, resulting in an intersexual conflict.