Context-dependent misclassification of masquerading prey
Masquerading prey resemble inedible objects such as leaves, twigs, stones and bird-droppings; and benefit because their predators misclassify them as the objects that they appear to resemble. From previous work on the importance of context cues in animal learning, we predict that predators will be less likely to misclassify masquerading prey as their models when they are found in a context in which predators have never before experienced the model. Here, we test this prediction using domestic chicks Gallus gallus domesticus as predators and twig-mimicking larvae of the Early Thorn moth Selenia dentaria as masquerading prey. We found that the benefit of masquerade was significantly larger when the twig-mimicking caterpillar was found in the context in which birds had previously experienced twigs. This suggests that masqueraders may have to pay opportunity costs associated with matching their models in position and microhabitat; and that predators’ classification decisions are complex and multi-factorial.
KeywordsMasquerade Crypsis Camouflage Predation Predator-prey Caterpillar
We thank NERC for funding; and John Delf, Hannah Rowland and Mike Speed for considerable help and advice throughout the project. We thank three anonymous reviewers for very helpful comments.
- Caro T (2005) Antipredator defences in birds and mammals. Chicago University Press, Chicago, pp 34–55Google Scholar
- Cott HB (1940) Adaptive colouration in animals. Methuen, London, pp 311–343Google Scholar
- Dockery M, Meneely J, Costen P (2009) Avoiding detection by predators: the tactics used by Biston betularia larvae. British J Entomol Nat Hist 22:247–253Google Scholar
- Edmunds M (1974) Defence in animals: a survey of anti-predator defences. Longman, HarlowGoogle Scholar
- Gluck MA, Mercado E, Myers CA (2008) Learning and memory: from brain to behaviour. Worth Publishers, New YorkGoogle Scholar
- Hailman JP (1977) Optical signals: animal communication and light. Indiana University Press, Bloomington, pp 174–176Google Scholar
- Krause J, Ruxton GD (2002) Living in groups. Oxford University Press, OxfordGoogle Scholar
- Ruxton GD, Sherratt TN, Speed MP (2004b) Avoiding attack: the evolutionary ecology of crypsis, warning signals and mimicry. Oxford University Press, OxfordGoogle Scholar
- Shettleworth SJ (2010) Cognition, evolution and behaviour, 2nd edn. Oxford University Press, OxfordGoogle Scholar
- Skelhorn J, Ruxton GD (2010) Predators are less likely to misclassify masquerading prey when their models are present. Biol Lett (in press)Google Scholar