The ostrich communal nesting system
Princeton University Press
, 1992 - Nature
- 196 pages
This book describes and presents new data on the ostrich communal nesting system, in which several females lay in one female's nest, with only one female and the male doing all the work. It unravels the basis of the cooperation observed, and explains how this unusual system involving apparent altruism is maintained by natural selection. The book is based on three field seasons of study of these unique, elusive birds in Tsavo West National Park in Kenya. The study depended on recognizing individual birds, detecting and monitoring well-concealed nests, determining motherhood of eggs from their surface appearance, and time-lapse photography of nests. Key findings were that females could switch rapidly between reproductive strategies, that a nesting female could recognize her own eggs and when necessary discriminate against those of other females, and that the whiteness of ostrich eggs is an adaptation which protects them against overheating but at the cost of greater vulnerability to predation. As the important field of study of cooperative breeding systems expands, a number of key species form the examples that underpin our general understanding of reproductive cooperation. The ostrich is increasingly becoming such a textbook species, on the basis of the results obtained in this study on vigilance and egg discrimination. In this extraordinary bird - the world's largest - it has been possible as never before to explain and quantify the effects of the different choices the birds make, and to integrate ecological and morphological factors' such as predation and large size. The book should act as both a catalyst and a model in the study of vertebrate behavioural ecology.