These are the questions that evolutionary biologist Wouter Halfwerk is trying to answer in the CAMOSENSE research project. He has been awarded a Vidi grant from the Dutch Research Council (NWO) for this project.
The way in which predators and prey interact often has a major effect on their entire ecosystem. Many of these interactions are characterised by an evolutionary arms race in which the prey evolve characteristics that help them to evade or escape their predators, who then adapt to become more efficient at finding and catching the prey.
Camouflage as a weapon
Camouflage plays an important role in this arms race, with prey animals in particular using it to conceal themselves. However, the effectiveness of camouflage is highly dependent on the predators’ sensory abilities and on the external characteristics that enable the prey to blend into their surroundings.
In the CAMOSENSE project, researchers are focusing on moths that need to conceal themselves from birds during the day and avoid bats at night. Bats locate the moths as they fly using ultrasound (echolocation). Songbirds move along the vegetation and visually search for resting moths.
Halfwerk explains, “In the lab, our research team recently showed that many moths are covered in hairs that can absorb ultrasonic sound waves. This stealth layer renders them ‘invisible’ to a bat’s echolocation system. In the Vidi project, we plan to explore the visual and acoustic characteristics of a large number of species. We want to identify the conditions under which they are likely to encounter certain predators, and the extent to which they are protected by camouflage.”
Setting up a database
These camouflage properties will be partly modelled and partly tested in behavioural experiments involving bats and songbirds. Ultimately, the researchers want to create a database of camouflage properties per species and per type of environment. “This database will enable researchers to predict how ecological communities might transform in response to climate change and urbanisation. They can also use it to predict insect infestations and the impact on biodiversity”, says Dr Halfwerk.
