Cuckoos evolve to fool angry birds

Jan 12, 2011
Cuckoos on left, respective host on right. Credit: N. Langmore

(PhysOrg.com) -- Australian cuckoo birds have taken a new evolutionary step – mimicking the color of their host young to avoid certain death, according to a study by researchers from The Australian National University.

Researchers from the ANU College of Medicine, Biology and Environment focused on three species of the Australian bronze-cuckoo. Their study found that these birds have evolved so that they no longer simply lay eggs that mimic their hosts, but they also match the color of their young to avoid eviction from the nest.

are known for their parasitic ways. They lay their eggs in the nests of other species, leaving their young to fend for themselves. Once hatched, cuckoo nestlings evict all host offspring from the nest to ensure the maximum chance of survival.

Dr. Naomi Langmore from the Research School of Biology, who led the research team, said that the host birds are unable to identify the cuckoos’ eggs from their own, so their primary line of resistance is to kill the cuckoos once hatched.

“Field experiments have shown that nestlings that look different from host young are more likely to be rejected by host parents,” she said.

To ensure that their young survive, she added, the cuckoos have taken evolutionary steps so that their newly hatched young are the same colour as their host ‘siblings’.

“We have demonstrated that bronze-cuckoo nestlings have co-evolved to be striking visual mimics of their hosts,” Dr. Langmore said.

“Host parents will kill a parasite hatchling within the first two days of its life. But by matching the color of the host young, the cuckoos are accepted by their ‘parents’. The mimicry only lasts for eight days, which is long enough for the acceptance to occur. After that, the pin feathers appear on the body, and the young cuckoos begin to look like their own species.”

Each of the three species of cuckoo has their own choice of host bird. In turn, they have each evolved to lay different colored young, ranging from black, to yellow, to pink.

Explore further: Lowly 'new girl' chimps form stronger female bonds

More information: The paper, ‘Visual mimicry of host nestlings by cuckoos’ is published in the current issue of the Proceedings of the Royal Society B.

Related Stories

Birds use social learning to enhance nest defense

Jun 04, 2009

Reed warblers live with the threat that a cuckoo bird will infiltrate their nest, remove one of their eggs, and replace it with the cuckoo's own. This 'parasitism' enables the cuckoo to have its young raised by unsuspecting ...

Cuckoo's copying an evolutionary curiosity

Mar 31, 2010

(PhysOrg.com) -- A new study of brood parasitism in birds has shown that the nest-poaching New Zealand shining cuckoo's ability to mimic its grey warbler host is an evolutionary curiosity.

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 ...

Cuckoo chicks in Zebra finches

Apr 22, 2010

(PhysOrg.com) -- Some female zebra finches foist a part of their eggs on their neighbours. Scientists of the Max Planck Institute for Ornithology in Seewiesen discovered that in every fifth nest there is one ...

Researchers crack cuckoo egg mystery

Sep 22, 2010

Researchers at the University of Sheffield have discovered that cuckoo eggs are internally incubated by the female bird for up to 24 hours before birth, solving for the first time the mystery as to how a cuckoo chick is able ...

Recommended for you

Our bond with dogs may go back more than 27,000 years

20 hours ago

Dogs' special relationship to humans may go back 27,000 to 40,000 years, according to genomic analysis of an ancient Taimyr wolf bone reported in the Cell Press journal Current Biology on May 21. Earlier genome ...

Social structure 'helps birds avoid a collision course'

23 hours ago

The sight of skilful aerial manoeuvring by flocks of Greylag geese to avoid collisions with York's Millennium Bridge intrigued mathematical biologist Dr Jamie Wood. It raised the question of how birds collectively ...

Orchid seductress ropes in unsuspecting males

23 hours ago

A single population of a rare hammer orchid species known as a master of sexual deception appears to have recently evolved to seduce a new and wider-spread species of impressionable male wasps.

Scientists announce top 10 new species for 2015

May 21, 2015

A cartwheeling spider, a bird-like dinosaur and a fish that wriggles around on the sea floor to create a circular nesting site are among the species identified by the SUNY College of Environmental Science ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

gwrede
1 / 5 (2) Jan 12, 2011
Maybe lying and cheating are good things to learn, after all? Maybe, instead of honesty, I should teach my children to cheat and lie more than other kids?
gvgoebel
5 / 5 (3) Jan 12, 2011
Well, gwede, that would be easier than teaching them to take over red blood cells and evade the immune system like a malaria parasite -- or lay their eggs in a host and let them devour it from the inside like a parasitic wasp. "Mother nature is a bitch. Deal with it."

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.