Common Cuckoos can distinguish the calls of their neighbors from a stranger's

March 13, 2017, The City University of New York
Common cuckoos are parasitic -- they are raised in the nests of other species. As adults, male cuckoos recognize their familiar neighbors and aggressively attack passing by stranger cuckoos: a phenomenon known as the Dear Enemy Effect. Credit: Csaba Moskat

Male cuckoos appear to have a unique call that makes them distinguishable to and from other males. A new study appearing in Animal Behaviour shows that an individual cuckoo call may determine how a male responds to an interloper in his territory—behaving more tolerantly towards neighbors and more aggressively towards strangers.

Common cuckoos, Cuculus canorus, are brood parasites: they lay their eggs in the nests of other bird species, and let these hosts incubate their eggs and feed and rear the nestlings. Although cuckoos do not show parental care, they demonstrate complex social behavior, including territoriality and male-male aggression. Cuckoos have a well-known and simple two-phrase ("cu" and "coo"), uttered by males during the . Previous studies have suggested that the "cu-coo" call of males is individually unique, allowing discrimination between different classes of males.

Researchers in central Hungary used playback experiments in a dense population of radio-tagged cuckoos to test whether neighboring males are tolerated more than unfamiliar intruders: the classic "dear enemy" phenomenon. The birds responded more aggressively to the calls of unfamiliar simulated intruders (strangers) than to the calls of conspecifics with whom they shared territorial boundaries (familiar neighbors). Cuckoos reacted within less than half a minute on average; they often approached the loudspeaker to within 5 to 10 meters from up to 80 meters away, and used their "cu-coo" calls in response. The birds used their simple call for the discrimination of familiar and unfamiliar individuals, and did so specifically to defend their own territories. In turn, they showed tolerance to nearby conspecifics, such as neighbors with overlapping territories. Since more than one cuckoo was interested in the playbacks, this study also confirmed the opportunity for brood-parasitic birds to socialize during the breeding season.

One of the study authors, Dr. Mark Hauber, Professor of Psychology, Hunter College, and Interim University Vice Provost for Research, City University of New York (CUNY), said, "This study is exciting for two reasons—it shows that brood parasitism is not an alternative for complex social dynamics in territorial birds. Also, song learning is not required for recognizing friends from enemies."

Future studies may examine the importance of individual call recognition, determine which parameter of the cuckoo call makes it unique, and clarify whether multiple overlapping territories, quasi "cuckoo hotspots," are related to the presence of female or driven by available host nests.

Explore further: Common cuckoo and warbler eggshells undergo similar levels of eggshell thinning

Related Stories

Birds find ways to avoid raising cuckoos' young

April 8, 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. Previous research ...

Why some cuckoos lay blue eggs

January 21, 2016

Cuckoos are nest parasites, meaning they lay their eggs in other birds' nests. The female cuckoo has to lay eggs that mimic the color, size and shape of the eggs of the host bird. Using a massive data set, including data ...

Egg colours make cuckoos masters of disguise

November 19, 2014

Cuckoos are notorious cheats. Instead of building a nest, incubating their eggs and raising their chicks, they lay their eggs in the nests of other birds and leave the task of raising their offspring to the unsuspecting host.

Recommended for you

New ant species from Borneo explodes to defend its colony

April 19, 2018

Amongst the countless fascinating plants and animals inhabiting the tropical rainforests of Southeast Asia, there are the spectacular "exploding ants", a group of arboreal, canopy dwelling ants nicknamed for their unique ...

Tiny fly blows bubbles to cool off: study

April 19, 2018

Humans sweat, dogs pant, cats lick their fur. Animals have adopted an interesting array of techniques for regulating body temperature through evaporation.

0 comments

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.