It’s an arms race between the patterns, colours and contrast of the eggs and the visual acuity of the predators
The researchers, from the University of Exeter and the University of Cambridge, travelled across Zambia and South Africa and took over 14,000 images and many hours of video footage as part of Project Nightjar. The aim was to work out which predators are able to see the hidden eggs of different ground-nesting birds. Back in the lab, they used specially customised software to recreate the visual world of the predators, analysing what makes objects blend in or stand out from their backgrounds, based on real field data – the first time that camouflage data has been directly linked to survival rates of real animals in the field.
The researchers have taken the analysis one step further by recruiting another predator: humans. By playing the ‘citizen science’ game Egglab, people can take their place in the evolutionary tree and spot eggs in images derived from the research. The eggs even ‘evolve’ as the game progresses, yielding yet more data on how types of camouflage evolve in different habitats.
Dr Jolyon Troscianko from the University of Exeter’s Sensory Ecology and Evolution group says Project Nightjar came about because theories about how camouflage works hadn’t been tested in the wild. “It’s very difficult to find a study system where you can link predation with the quality of an animal’s camouflage,” he said.
Along with co-principal investigators Dr Martin Stevens, also from the University of Exeter, and Dr Claire Spottiswoode from the University of Cambridge, the team developed a study system using two classes of ground-nesting birds inspired by Spottiswoode’s previous encounters with nightjars in Africa. “I was bowled over by their camouflage, which led to discussions with Martin about how we could take advantage of these birds for camouflage research, leading to our collaboration on the current project,” she said.
Watch the video and read the full story
Image:Mozambique Nightjar
Credit: Dr Claire Spottiswoode
Reproduced courtesy of the University of Cambridge
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