Non‐morph specific predation of peppered moths (Biston betularia) by bats

Abstract

Abstract 1. Industrial melanism in the peppered moth, Biston betularia, is one of the foremost examples of natural selection in action.2. Differential bird predation was suggested as the main agent for the evolution of melanism in the peppered moth by Tutt in the 1890s, with empirical support being published by Kettlewell in the 1950s.3. Some recent critiques that have attempted to undermine Kettlewell’s work have lacked objectivity, and have been answered previously.4. One criticism that has not previously been addressed is that of the role of bat predation in the case.5. The difficulty of using non‐visual differential predation by bats to explain the increase and decrease in melanism in the peppered moth, correlated as it is to pollution levels, is outlined.6. Predation experiments, in which moths of the typica and carbonaria forms of the peppered moth were released and observed at night, were used to determine whether bats differentially predate these forms.7. Results of experiments at three sites showed no significant differences in the level of bat predation of the two forms of peppered moth.