Scientists expose true extent of cuckoo's cunning

September 4, 2017

The common cuckoo, notorious for evading parental duty by hiding her eggs in the nests of other brooding birds, is even more devious than previously thought, scientists revealed on Monday.

After laying an egg, the female distracts the owner of the nest—a reed warbler in this case—essentially by frightening the poor bird out of its wits, they said.

The cuckoo gives a "chuckle" that mimmicks the call of the sparrowhawk—which loves to snack on warbler flesh—before abandoning her egg among the warbler's clutch and flying off to freedom.

"This hawk-like chuckle call increases the success of parasitism by diverting host parents' attention away from the clutch and towards their own safety," a duo of Cambridge University researchers wrote in the journal Nature Ecology & Evolution.

"As a result, the female cuckoo might have 'the last laugh' in this particular battle."

The bird whose behaviour gave us the word "cuckoldry", is an example of a "brood parasite"—birds, insects or fish that trick others into raising their young.

This is often at the expense of the foster parents' own offspring.

To avoid getting caught—which will lead to the imposter egg being kicked out of the nest—the cuckoo has developed some nifty tricks, including matching its egg colouring to that of its target, for camouflage.

The bird has also adopted "remarkable secrecy and speed" in depositing its egg, said the team.

For this reason, scientists have battled to understand why the cuckoo would risk exposure by "chuckling" so soon after committing its crime.

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Clever Bird: Magpie Mimics Human Child

14:29 22.11.2015(updated 14:31 22.11.2015) 

Magpie learned to copy human speech.

Turns out that parrots aren't the only avians capable of imitating human speech. Check out how this magpie can mimic a child's laughter.

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Deceptive woodpecker uses mimicry to avoid competition

Date: August 11, 2015

Source: Central Ornithology Publication Office

Summary: Birds of a feather may flock together, but that doesn't mean they share a genetic background. Though birds were first classified into groups primarily based on appearance, research demonstrates that this method isn't necessarily accurate: in a group of very similar-looking South American woodpecker species, genetic analysis has now shown one to be only a distant cousin of the others, in an intriguing case of visual mimicry.

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Tiny birds ‘cry hawk’ to give offspring chance to escape predators

Date:

June 2, 2015

Source:

University of Cambridge

Summary:

New research has found that the 6 gram brown thornbill mimics the hawk alarm calls of neighboring species to scare a nest predator by convincing it that a much bigger and scarier predator -- the brown goshawk -- is on its way.

Currawongs, which raid the nests and hunt the chicks of thornbills, are also prey to goshawks. Although currawongs normally benefit from listening in on hawk alarm calls of other species, thornbills exploit this and turn it against them.

As well as issuing their own hawk alarm call, thornbills mimic those of the local species to create the impression of an impending hawk attack, which in turn distracts the pied currawong -- a predator 40 times larger than the thornbill -- providing thornbill nestlings with an opportunity to escape.

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Hidden in plain sight: Amazonian bird chick mimics toxic caterpillar to avoid being eaten

Date:

February 23, 2015

Source:

University of Chicago Press Journals

In a study published in the January 2015 issue of The American Naturalist, Gustavo A. Londoño, Duván Garcia, and Manuel Sánchez Martínez report a novel nesting strategy observed in a tropical lowland bird that inhabits an area with very high losses to nest predators.

How can tropical birds cope with the high rates of nest predation that are typical in most tropical habitats? Are there nesting strategies that allow tropical birds to escape predators such as birds, mammals, and snakes that regularly eat eggs and nestlings?

During the fall of 2012, while working on a long-term avian ecological study, the researchers discovered the second nest ever described for the cinereous mourner (Laniocera hypopyrra) at Pantiacolla Lodge in the upper Madre de Dios River in southeastern Peru. They observed that upon hatching, the chicks had downy feathers with long orange barbs with white tips, which was very different from any other nestling they had observed in the area. The peculiar downy feathers attracted their attention, but the nestling behavior provided a more important cue. While researchers were collecting morphological measurements, the nestling started moving its head very slowly from side to side in a way typical of many hairy caterpillars. While working in the area, the investigators found a poisonous caterpillar with similar size and hair coloration as the nestling. Therefore, the researchers suggest that this is an example of Batesian mimicry in which the nestling tricks predators into thinking that it is a toxic, spiny caterpillar rather than a highly edible nestling.

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