Key Insights – Mokkonen et al. 2012

Mokkonen M., E. Koskela, T. Mappes & S.C. Mills. 2012. Sexual antagonism for testosterone maintains multiple mating behaviour. Journal of Animal Ecology 81: 277-283.

OVERVIEW:
This study used artificial selection for plasma testosterone (T) in bank voles to study the effect on female and male multiple mating behaviour. T increases male mating success, yet little is known about the impact of testosterone selection on female mating behaviour. 

NOVEL FINDINGS:
-selecting for T increased male mating success, but decreased female mating success.
-positive Bateman gradients for both females and males; multiple mating behaviour benefited both sexes through greater reproductive success.
-polyandry decreased the fitness of males

OTHER NOTABLE DETAILS:
-the sexually antagonistic selection of testosterone maintains multiple mating behaviour in bank voles
-female litter size increased with the number of partners, which may provide a mechanism for females to regulate their reproductive effort based on environmental conditions