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 broods being fed by their foster parents are much lower, according to research led by Manuel Soler of the Universidad de Granada in Spain. The findings are published in Springer's journal Behavioral Ecology and Sociobiology.

The post-fledging period is a critical phase for juvenile survival during which parental care is still very important. This is also true for inter-specific , whose offspring are incubated and raised by members of other species. Very little is known however about the relationships between foster parents and fledglings of brood parasites. Sometimes, great spotted cuckoo and magpie nestlings from the same can fledge successfully, but most often parasitic nestlings out-compete host nestlings and only cuckoos leave the nest.

Soler and his team studied the brood parasitic great spotted cuckoo (Clamator glandarius) and its magpie (Pica pica) over the course of five breeding seasons. Aspects of cuckoo post-fledging performance, such as feeding behavior, parental defense and fledgling survival, were studied in experimental nests in which only cuckoos or both magpie and cuckoo nestlings survived until leaving the nest. Some of the fledglings were also radio tracked. The study was the first to focus on the defense behavior of adult magpies towards parasite fledglings.

They found that great spotted cuckoo fledglings are more frequently fed by magpie hosts when they are reared in nests with cuckoo-only broods, compared to those reared sharing the nest with host nestlings. This is especially true in the first three weeks after fledglings leave the nest. These are the first experimental results to show the importance of the nest situation for the performance of brood parasite fledglings.

The results support the idea that magpies are capable of discriminating cuckoo fledglings when they are allowed to compare them with their own fledglings. The researchers believe that the difference disappeared three weeks after leaving the nest because fledgling cuckoos by then tend to join cuckoo groups that are communally fed by more magpies than those involved in rearing the cuckoos in the nest.

"The presence of the host's own for comparison may be a crucial clue favoring the evolution of fledgling discrimination;" writes Soler. "Furthermore, the risk of discrimination at the fledgling stage probably is an important selection pressure driving the evolution of the arms race between brood parasites and their hosts."

Explore further: Cheats of the bird world: Cuckoo finches fool host parents

More information: Soler, M. et al (2013). Great spotted cuckoo fledglings are disadvantaged by magpie host parents when reared together with magpie nestlings, Behavioral Ecology and Sociobiology. DOI: 10.1007/s00265-013-1648-9

add to favorites email to friend print save as pdf

Related Stories

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 evolve to fool angry birds

Jan 12, 2011

(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 ...

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 ...

Recommended for you

Lemurs match scent of a friend to sound of her voice

14 hours ago

Humans aren't alone in their ability to match a voice to a face—animals such as dogs, horses, crows and monkeys are able to recognize familiar individuals this way too, a growing body of research shows.

Love-shy panda artificially inseminated

23 hours ago

Britain's only female giant panda, Tian Tian, has been artificially inseminated after failing to mate with her male partner Yang Guang, Edinburgh Zoo said Tuesday.

User comments : 0

More news stories

Ranchers benefit from long-term grazing data

Scientists studying changes in the Earth's surface rely on 40 years of Landsat satellite imaging, but South Dakota ranchers making decisions about grazing their livestock can benefit from 70 years of data ...

Floating nuclear plants could ride out tsunamis

When an earthquake and tsunami struck the Fukushima Daiichi nuclear plant complex in 2011, neither the quake nor the inundation caused the ensuing contamination. Rather, it was the aftereffects—specifically, ...

Unlocking secrets of new solar material

(Phys.org) —A new solar material that has the same crystal structure as a mineral first found in the Ural Mountains in 1839 is shooting up the efficiency charts faster than almost anything researchers have ...