Just winging it!

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‍Scientists have found that 52 different bird families rely on the risky display technique of 'faking' a broken wing to protect their nests, including some songbirds. The researchers from the Max Planck Institute in Germany as well as California Polytechnic State University have published a new paper in Proceedings of the Royal Society B: Biological Sciences which outlines these fascinating findings.

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Broken-wing displays are interesting within the field of animal behaviour, because honesty is usually the best policy! They are a form of deception, which is typically selected against in nature, where honest communication is the top priority between individuals of the same species. However, deceptive behaviour has been shown to occur where animals feel vulnerable to predation and have no better form of defence.

Broken-wing displays are used by some to lure away predators from their nests, by feigning a wing injury and dragging their wing along the ground. This allows the predator to become distracted by an easier ‘snack’ and leave the nest to follow the injured parent. This behaviour is commonly witnessed in ground-nesting waders like the ringed plover or killdeer, where nests are low to the ground and obvious to nearby predators.

This study used a combined approach of surveying ornithologists, birders, and avian researchers, in addition to an evidence review, to identify which species were found to have used feigning an injury to dupe predators. Researchers found that not only is this behaviour not specific to shorebirds, but it is widespread within 52 different bird families and in over 250 species. Members of the warblers, thrushes and tits have been shown to exhibit this behaviour, and the vast array of species that it is present in suggests that it evolved independently in birds facing the same kind of threats under different environmental conditions.

Birds with open nests (ground-nesters and exposed nests) were more likely to use this type of behaviour. Whereas cavity-nesting birds, such as woodpeckers and kingfishers, were markedly absent from displaying it. It was also found that birds who ‘mob’ (aggressively fly at) predators are more likely to fake a broken wing.

Latitude was also found to correlate with the use of this anti-predator behaviour. This is largely due to the number of hours that are light and the level of predation risk. Bird species that have fewer broods and more chicks were also more likely to try this risky behaviour, signalling reproductive success is paramount to these species and that the defence of their current nest outweighs the risk of their own possible predation.

This study shows that you never know if your favourite songbird has something new up their sleeves that you’ve never witnessed before. So, keep your eyes open and your binoculars clean when birdwatching and try to catch sight of your favourite feathered friends fooling their predators!

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The SBS Team

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If you are a scientist and would like to shine a light on your recent research covering songbirds here in the UK, then let us know! As a supporter of our charity, if you have ideas for blog posts you would like to see and topics you would like us to cover on #theSBSblog, please contact us at dawn-chorus@songbird-survival.org.uk or our Research and Engagement Manager at charlotte@songbird-survival.org.uk. 

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