In the "novel world" great tits Parus major forage on artificial black-and-white prey in a black-and-white laboratory environment built in indoor aviaries. Prey items are pieces of almond in paper shells with printed black symbols on both sides. Cryptic prey are prey items with a symbol that matches the background whereas aposematic prey have visible symbols. In this artificial world it is possible to manipulate signal conspicuousness, signal accuracy of mimetic prey, absolute and relative abundances of the prey types, distastefulness of the prey and so on. Because the prey and signals are artificial, wild predators can be used as naïve predators or, with pre-training, as experienced predators. This laboratory system is used to study the initial evolution of aposematism, mimicry and dietary conservatism.
Short video clip (.wmv) about the method.
The tiger moth Parasemia plantaginis is a polyphagous herbivore. The larvae of P. plantaginis have an orange patch on the otherwise black and hairy dorsal side. Hairs of the larvae can be used as a mechanical defence; the hairs break when touched causing irritation. The larvae are also chemically defended: the intensity of chemical defence varies among individuals feeding on different host plants. Furthermore, the size of the orange patch, which is a warning signal, varies considerably among individuals. We use this species to study the benefits of conspicuous signalling, trade-offs between producing (and maintaining) a warning signal and other life-history traits as well as environmental constrains to signal expression.
