Birds in love produce more babies, study shows

A study finds that birds who freely choose their own mates have 37% more offspring than those which were paired up by researchers in a sort of avian ‘arranged marriage’

True love: a pair of zebra finches bond in a laboratory study that examined the evolutionary value of love. (Credit: Wolfgang Forstmeier/Malika Ihle et al)

Birds who freely choose their own mates produce 37 percent more offspring than those which were paired up by researchers in an avian “arranged marriage”, according to research published today in the peer-reviewed journal, PLoS Biology. Additionally, cross-fostering experiments revealed that embryo mortality depended upon the compatibility of the genetic parents, whereas chick mortality depended upon the the behavioural compatibility of the foster parents. Further, although parents that freely chose their own mates had similar rates of embryo mortality to that of birds in “arranged marriages”, those birds that freely chose their own mates were much better at raising their chicks. This suggests that birds may be choosing mates based on behavioural compatibility -- a finding that has important implications for conservation of animals that form pair-bonds.