A new study shows that young birds raised under stressful conditions leave home earlier and develop a wider social network.
The paper co-authored by Damien Farine, now a post-doctoral researcher at the University of California, Davis, anthropology department, Neeltje Boogert, University of St Andrews, and Karen Spencer, Oxford University, was published in Biology Letters Wednesday, Oct. 29.
The researchers found that zebra finch chicks stressed during early development showed more independence from their parents, associated more randomly with other members of their flock and were less choosy about the birds they fed alongside.
“Stress is a possible mechanism to allow birds to try alternative strategies,” Farine said. “If you get a lot of this stress happening you may see them doing behaviors they have done before including widespread dispersals. When we see birds popping up in places they’ve not been before it might have something to do with stressful development. This could thus have major implications for maintaining locally-adapted behaviors and genetic structure across different sub-populations.”
Wild birds secrete a stress hormone when faced with food scarcity, predators or competition. The researchers artificially increased stress hormone levels in zebra finch chicks and tested how this affected their foraging behavior. The birds’ were monitored in aviaries where the stressed chicks and their families could visit bird feeders at any time and with any other birds. Each bird was fitted with a chip that recorded each time a bird visited one of the feeders over the course of five weeks.
For the full study go to http://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2014.0561.
Follow Damien Farine on Twitter at @DamienFarine.
Contributed by Jeffrey Day.