MATE-CHOICE COPYING IN BLACK GROUSE

Recent field studies of lekking birds and mammals have provided eviden ce that mate selection in these mating systems may be affected partly by females copying the choices of others. Two pieces of evidence from black grouse, Tetrao tetrix, leks consistent with this view are presen ted. First, data on the temporal distributions of natural matings at 1 9 leks show that after being chosen by one female, a male is more like ly to be chosen by others. Second, in an experiment in which dummy fem ales were placed on males' territories, more females were attracted to the territories on days when males were able to copulate with the dum mies. This result was not repeated in two other treatments when males were presented with dummies with which they were not able to copulate or with decoys of ducks. This suggests that copulation itself makes a male more attractive to females, although several other cues might als o have contributed to the responses observed in these experiments.