What are the implications if moths rest most often underneath branches?
Leaving aside Wells’s frantic attempt to create a problem where none exists, the relevance of moth resting locations for the ‘classic story’ (natural selection by bird predation) deserves some consideration. Majerus’ considered opinion is that peppered moths rest more commonly underneath branches than was previously appreciated, and that if this is true then some quantitative estimates of selection coefficients may need to be adjusted. However, he is quite clear that the basic qualitative conclusions of Kettlewell (that differential bird predation of moth morphs on changing backgrounds is the selective force) do not need to be changed. As Majerus notes, crypsis is still important for moths in tree branches. He even comments directly on this with two of his photos (Plate 3, photos (b) and (c)). And of course, birds are known to (a) fly and (b) feed in forest canopies, so it is very difficult to see why resting on trunks vs. branches would change bird predation in any radical way.
