Sydney, May 3 (IANS) Why some birds help raise offspring which aren’t their own has been an endearing mystery. But it now turns out that they may be doing so to produce future helpers for themselves.
Michelle Hall, visiting fellow at the Australian National University Research School of Biology, said fairy-wrens are habitual cooperative breeders, but it boils down to both family and inheritance.
‘For example, in purple-crowned fairy-wrens over 60 percent of helpers live with both parents in the territory they hatched on and over 90 percent live with at least one parent. So the young they help raise are usually siblings or half-siblings,’ said Hall, The American Naturalist reports.
Hall, who co-authored a long-term study on the subject, said: ‘In general, helpers that are more closely related to the nestlings provide more help and their efforts thus see more of their shared genes entering the gene pool.’
While the findings may explain unexpected animal altruism, Hall said they are by no means universally observed, according to a School of Biology statement.
‘In a twist, some helpers in purple-crowned fairy-wrens, and other cooperative breeders, also provide help for unrelated young in the nest. But it turns out these helpers are also playing a selfish game and maximising direct benefits by producing future helpers of their own.
‘They help when their chances of inheriting the current breeding territory are greater, and thus are helping to raise their own future assistants,’ Hall concluded.
Sjouke Kingma from the Max Planck Institute for Ornithology led the study along with Anne Peters from Monash University.
