TERRITORIALITY AND SONG AS FLEXIBLE PATERNITY GUARDS IN DUNNOCKS AND ALPINE ACCENTORS

I compare paternity defense strategies in the variable mating systems of alpine accentors Prunella collaris and dunnocks P. modularis. I sho w that in dunnocks breeding territoriality functions exclusively for m ate defense. Male investment in territoriality increases with the numb er of females they are defending, and when females are removed males s harply decrease their song output and eventually abandon their territo ries. Further, I show that paternity defense strategies vary in relati on to group composition. In single-male groups there is greater invest ment in territorial defense and less investment in mate guarding durin g the female fertile period than in multimale groups. I discuss the in fluence of the contrasting habitats of dunnocks and alpine accentors o n their paternity defense strategies.