Cooperation helps mammals survive in tough environments.
Cooperatively breeding mammal species, such as meerkats and naked-mole rats, where non-breeding helpers assist breeding females in raising their offspring, are better able to cope with living in dry areas than related non-cooperative species, new research reveals.
A comparative study of mammals, by University of Cambridge researchers Dieter Lukas and Tim Clutton-Brock, shows that cooperatively breeding species occur in dry areas, yet are absent in tropical climates — even though these are the places on earth with the highest biodiversity.
"Rainfall often affects food availability, and cooperatively breeding mammals appear better able to cope with the uncertainties of food availability during periods of drought," said Lukas, from Cambridge’s Department of Zoology.
In this study, published in the journal Royal Society Open Science, the researchers mapped the global occurrence of mammalian species living in different social systems to determine how averages and variation in rainfall and temperature explain species distributions.
They found that although the presence of non-breeding adults in breeding groups is not associated with contrasts in climate, non-breeders commonly play an important role in raising the offspring of breeders in species living in dry environments.
"Long-term field studies show that helpers improve offspring survival, and our findings highlight that such cooperation is particularly important under harsh conditions," said Clutton-Brock.
Groups of cooperative breeders occupy territories year-round.
Cooperative breeders are also twice as likely as non-cooperative mammals to occupy human-modified habitats suggesting that cooperative breeding may make it possible to colonize new environments.
Story Source: Materials provided by University of Cambridge.