Sunday, July 17, 2011

Some Now Or More Later In Moth Reproduction

The abstract from a (gated) paper by Nokelainen et al:
[Wood tiger moth males] have two distinct colour morphs: white and yellow. The efficacy of the warning signal of these morphs was tested by offering them to blue tits in the laboratory. Birds hesitated significantly longer to attack yellow than white males. In a field experiment, the survival of the yellow males was also higher than white males. However, mating experiments in the laboratory revealed that yellow males had lower mating success than white males. Our results offer an explanation for the maintenance of polymorphism via trade-off between survival selection and mating success.
Yellow moths are less likely to be attacked because their conspicuous color acts to fend off predators. On the other hand, the authors cannot suggest a clear reason for why white male moths have greater mating success. Whatever the mechanism is, this is a clear example of some now vs more later in evolution.