Chickless birds guard nests of relatives

Dec 20, 2013 by Andi Horvath
Chickless birds guard nests of relatives
Helper Fairy Wren scrutinising an invading cuckoo.

(Phys.org) —New research has solved a mystery as to why some birds choose not to reproduce, and instead help to guard the nests of their close relatives. This occurs in about nine percent of all bird species.

The University of Melbourne collaborated in a study led by ANU and Cambridge University. The findings showed non-breeders helped drive off birds like cuckoos, which lay their eggs in the of other birds.

"Birds like Cuckoos are called , which means they are reproductive cheats. They lay their eggs in the nests of other birds, imposing the costs of rearing on their hosts, who often lose their entire brood of chicks as a result," said Dr Naomi Langmore the lead investigator at ANU.

"Biologists have long wondered how this strategy, termed cooperative breeding, could be evolutionarily successful," she said.

Dr Michelle Hall and Associate Professor Raoul Mulder, coauthors on the study from the Department of Zoology, University of Melbourne, said "When it comes to guarding the nest, if there is extra help for the breeding pair, it enhances protection against brood parasites, and the chances that their own chicks will survive."

The team from the University of Melbourne contributed to the study with data from over 100 families of superb fairy wrens living at Serendip Sanctuary, near Melbourne and Campbell Park, near Canberra. Our data helped show that nests of larger family groups were less likely to contain cuckoo eggs than nests of small family groups. Experiments with model cuckoos conducted at Serendip Sanctuary showed that bigger host groups of birds aggressively mob the invading at their nests much more than smaller groups.

"Understanding this interaction between cooperative breeding and brood parasites also helped explain the uneven global distribution of cooperative breeding ," said Dr Hall. The global distribution of cooperative breeders and brood parasites is tightly linked and concentrated in two major geographic hotspots: Australasia and sub-Saharan Africa.

The findings have been published in the journal Science.

Explore further: Magpie parents know a baby cuckoo when they see one

More information: "Brood Parasitism and the Evolution of Cooperative Breeding in Birds," by W.E. Feeney et al. Science, 2013.

Related Stories

Magpie parents know a baby cuckoo when they see one

Dec 11, 2013

Cuckoos that lay their eggs in the nest of a magpie so that their chicks can be raised by the latter better hope that their young are not raised together with other magpies. The chances of cuckoo fledglings raised in mixed ...

Birds find ways to avoid raising cuckoos' young

Apr 08, 2013

Some species of birds reproduce not by rearing their own young, but by handing that task on to adults of other species. Known as brood parasitism, this habit has been most thoroughly researched in the cuckoo. ...

Cuckoos impersonate hawks by matching their 'outfits'

Oct 16, 2013

New research shows that cuckoos have striped or "barred" feathers that resemble local birds of prey, such as sparrowhawks, that may be used to frighten birds into briefly fleeing their nest in order to lay ...

Birds' strategic mobbing fends off parasitic invaders

Jan 29, 2009

Reed warblers use mobbing as a front line of nest defense against parasitic cuckoos, according to a new report published online on January 29th in Current Biology, a Cell Press publication. Cuckoos act as parasites by lay ...

Recommended for you

Transparent larvae hide opaque eyes behind reflections

3 hours ago

Becoming invisible is probably the ultimate form of camouflage: you don't just blend in, the background shows through you. And this strategy is not as uncommon as you might think. Kathryn Feller, from the University of Maryland ...

Peacock's train is not such a drag

4 hours ago

The magnificent plumage of the peacock may not be quite the sacrifice to love that it appears to be, University of Leeds researchers have discovered.

Spy on penguin families for science

11 hours ago

Penguin Watch, which launches on 17 September 2014, is a project led by Oxford University scientists that gives citizen scientists access to around 200,000 images of penguins taken by remote cameras monitoring ...

User comments : 0