The surprising discovery of this study is that hosts achieve egg recognition in different ways
Rebecca Kilner
For some birds, recognising their own eggs can be a matter of life or death.
In a new study, scientists have shown that many birds affected by the parasitic Common Cuckoo - which lays its lethal offspring in other birds’ nests - have evolved distinctive patterns on their eggs in order to distinguish them from those laid by a cuckoo cheat.
The study reveals that these signature patterns provide a powerful defense against cuckoo trickery, helping host birds to reject cuckoo eggs before they hatch and destroy the host’s own brood.(Image removed)
To determine how a bird brain might perceive and recognize complex pattern information, Dr Mary Caswell Stoddard at Harvard University and Professor Rebecca Kilner and Dr Christopher Town at the University of Cambridge developed a new computer vision tool, NATUREPATTERNMATCH. The tool extracts and compares recognizable features in visual scenes, recreating processes known to be important for recognition tasks in vertebrates.
“We harnessed the same computer technology used for diverse pattern recognition tasks, like face recognition and image stitching, to determine what visual features on a bird’s eggs might be easily recognised,” explained Stoddard.
Using the tool, the researchers studied the pigmentation patterns on hundreds of eggs laid by eight different bird species (hosts) targeted by the Common Cuckoo.
Inset image: Reed Warbler caring for Cuckoo chick. Credit: David Kjaer
Main image: NATUREPATTERNMATCH extracts visual features, here represented by magenta vectors (left). Three eggs each (represented in different rows) laid by three different Great Reed Warblers are shown here (right).
Credit: Mary Caswell Stoddard/Natural History Museum
Reproduced courtesy of the University of Cambridge
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