Plenty of fish yet
male voles choose monogamy
… but do their partners?
Monogamy is relatively rare in the animal kingdom, with extra-pairs matings happening a lot more than you might think. Males in particular are thought to gain the most from polygamy by being able to sire multiple offspring, whilst females may gain from monogamy through defence or paternal care of their young.
Yet despite having access to multiple females, male prairie voles choose to form exclusive pair bonds with individual females (Blocker & Ophir, 2016). In contrast, female prairie voles readily engage in promiscuous mating (Wolff et al, 2002).
So why (under laboratory settings) are male prairie voles monogamous whilst females are promiscuous?
Blocker & Ophir, 2016 argue that one explanation could be that the costs to males of trying to hang on to multiple females at once are too great, and that male prairie voles gain the most by aggressively monopolising just one female. Females on the other hand have nothing to lose from polygamy so will mate with other males if the opportunity presents itself.
In prairie voles it seems that monogamous behaviour may be male-driven.