The control of prolactin secretion and nest defence in the ring dove (Streptopelia risoria)

Abstract

Abstract The ring dove is a member of the Columbidae in which both sexes share in the incubation of two eggs. It is unlike other avian species in that the concentration of plasma prolactin does not begin to increase until several days after the initiation of incubation to reach a peak at the time of hatch. It appears that this increase is triggered by the length of time of sitting and possibly responds to a tactile component. However, unlike in those species where one sex alone participates in incubation, visual stimuli do maintain the elevated levels of prolactin in the broding dove. An increase in prolactin concentration is considered to be responsible for an increase in aggressive behaviour shown by doves at the time of hatch and whilst brooding the young. Data are presented to illustrate those agonistic responses which constitute nest defence during the breeding cycle. The involvement of both environmental and hormonal influences in the induction of such behaviour is discussed.