Female strawberry poison dart frogs can be non-choosy when it comes to finding a mate concludes research published in Frontiers in Zoology today. In a population with a strongly biased sex ratio and low trait variance between males, females receive no benefit from expending energy and effort searching out the ‘fittest’ mate. Instead they lose no time in seeking out the male in the closest proximity as a partner.
Ivonne Meuche, from the University of Veterinary Medicine Hannover, and her team continuously observed mating behaviour of 20 female Oophaga pumilio frogs, during the time period between two successive ovipositions. In parallel, they measured surrounding males’ behaviour and spatial distribution in order to establish what was important to females when choosing a male to mate with. In most lek mating systems, where a number of males are present and thereby may compete for female attention, females will chose males based on heritable traits or assumed parenting skills. However, Meuche found that in this population, there was no correlation between mating success of a given male and any physical or acoustic trait measured, or territory size. Unusually, in this system, females selected males purely based on proximity.
The function of male display characteristics and behaviours is a well discussed topic of research for behavioural and evolutionary biologists. This study demonstrates an interesting example of an unusual female sampling tactic whereby females will accept the closest male as a mate. The authors suggest that in this system, this is an optimum tactic due to low fecundity and low benefits of intensive mate sampling – hence there is little to gain by being a picky female. Further investigation is required to discover whether all strawberry poison dart frogs show these levels of indifference towards their mate choices.