Effects of different methods of non-lethal tissue sampling on butterflies


Lindsay A. Crawford, Department of Biology, University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada. E-mail: lcrawfo6@uwo.ca


1. We investigated the effects of two methods of non-lethal tissue sampling on post-release flight behaviour (short-term response) and survival (long-term response) of two butterflies, Pieris rapae and Coenonympha tullia, within the same natural habitat. We applied three treatments: control (no tissue removal), wing clipping, and leg removal. Our study is the first to directly compare the effects of these common sampling methods.

2. We monitored the flight behaviour of the butterflies by following individuals immediately after their release. In 99 behaviour trials of P. rapae and 101 of C. tullia we found no significant differences in proportion of time spent flying or displacement per unit time among treatment groups in either species.

3. We used standard mark–recapture techniques continuously throughout the flight season to compare the survival of individuals. We marked a total of 687 P. rapae and 490 C. tullia butterflies. We found no significant differences in survival among treatments in either species.

4. We detected differences between the sexes in survival in P. rapae and flight behaviour in C. tullia. In addition to indicating differences in ecology between the sexes, these results also suggest that our analyses were sufficiently powerful to detect a significant effect of tissue removal had such an effect existed.

5. Our work is an important addition to the accumulating evidence that these methods of non-lethal tissue sampling are generally not detrimental. These sampling techniques closely mimic conditions in the wild, as wing wear and leg losses occur naturally.