Male birds with bolder personalities who more proactively explore new environments form stronger attachments with females before they mate, reports a study published online this week in Nature Ecology and Evolution. This finding suggests that differences in the behaviour of individuals could influence the structure and dynamics of animal social networks.
Around 90% of bird species form socially monogamous pairs, with longer-lasting relationships shown to be associated with increased reproductive outputs. However, the factors that influence the formation of these bonds are less well understood.
Josh Firth and colleagues tracked the social network associations of great tits in a wood near Oxford, England, over three years. Every bird captured in the wood was fitted with an identifying microchip to track individuals that consistently associated with each other in flocks. They then underwent a standardised ‘personality’ test to see how proactive, or bold, those individuals are in exploring new environments.
Analysing the social network associations of these birds over time as the mating season approached, the authors find that more proactive males met their future partners sooner and developed stronger network associations with their mates at a faster rate than the less bold males. However, they find that the strength of pair-bonds is unrelated to personality in female birds.