At first sight just a small brown bird, the dunnock's unobtrusive appearance belies its extraordinary behaviour and mating patterns. In this book Nick Davies gives a full account of the mating systems of the dunnock or hedge sparrow, Prunella modularis, which include pairs, a male with two females, two males with one female, and several males with several females. Detailed observations, elegant field experiments, and DNA fingerprinting are combined to show how this variable social organization from selfish individuals competing to maximize their own reproductive success. Further experiments reveal how the cuckoo may thwart the dunnock's parental efforts. David Quinn's exquisite drawings provide a visual summary of the birds' behaviour. All students of ecology, evolution, and animal behaviour will want to be familiar with this work, which addresses the wider issues of the influence of ecology on mating systems and the evolutionary significance of conflict within and between species. This is the third volume in the Oxford Series in "Ecology and Evolution", and the first in this series to tackly behavioural ecology. Nick Davies is a Lecturer in Zoology at the University of Cambridge and co-editor with J. R. Krebs of the leading text in the field, Behavioural ecology: an evolutionary approach.