Some Social and Hormonal Determinants of Nest-Building Behaviour in the Ring Dove (Streptopelia Risoria)

Two experiments were performed to evaluate some of the controlling factors in ring dove nest-building behaviour. In the first study six pairs of animals were observed each day until the first egg appeared. Behaviour was recorded during four intervals on each day in order to obtain estimates of diurnal changes in behaviour. Moreover, each pair was presented with a variety of nest-building materials in order to determine those kinds that would be most acceptable to the animals in subsequent studies. The birds showed striking diurnal changes in behaviour. Bow-cooing, aggressive pecking by the male, nest soliciting, time-in-the-nest, and allopreening exhibited a steady decline throughout the day. Nest-building activity reached a peak between one and seven hours after the lights came on in the morning and then declined throughout the remainder of the day. By contrast, copulatory behaviour, though infrequent in the morning hours, rose sharply in the late afternoon and reached a peak during the evening watch. Feeding and self-preening also increased slightly during the afternoon and evening. The ring doves also showed marked preferences in their choice of nest materials. Light-colored reed was preferred almost exclusively to dark-colored reed. Moreover, as nest construction progressed, there was a change in the type of material collected. During early building approximately equal numbers of pine needles as well as light and heavy reed were collected. As the nest neared completion, reed collection diminished and pine needles alone were collected. The resulting structure consisted of a base of several materials lined with pine needles alone. Observations in this first experiment suggested that gathering activity by the male was elicited by the presence of the female in the nest site. A second experiment was designed to examine this relationship. Twelve female ring doves were injected with progesterone and diethylstilboestrol while another twelve females served as oil-injected controls. Hormone-treated females were found to become more firmly established at the nest site during the first two days after introduction to a male. The males mated with these hormone-treated females engaged in more nest material gathering than did males mated with oil-treated females. It was concluded that gathering behaviour by the male is determined, at least in part, by relevant social cues from the female.