Ecophysiology and evolution of sex roles in monogamous and polyandrous coucals
Black coucals (Centropus grillii), white-browed coucals (C. superciliosus) and coppery-tailed coucals (C. cupreicaudus) breed in the swampy grasslands of sub-Saharan Africa. In some places the closely related species occur in the same habitat and breed during the same time of the year, often in close proximity to one another. But they show extreme differences in their mating system.
White-browed and coppery-tailed coucals are socially monogamous, which means that one female and one male form a pair and sing duets. Both females and males incubate the eggs and feed the young. Black coucals are sex-roles are reversed: Females are almost twice as large as males; each female sings and defends a large territory, in which she 'pairs' with up to 5 males simultaneously (polyandry). In contrast, male black coucals rarely sing, but incubate the eggs and feed the young without any help from the female.
Which ecological and evolutionary factors have led to the dramatic differences in behaviour and life histories of these three coucal species? And which physiological mechanisms drive the differences in behaviour? To approach these evolutionary and eco-physiological questions we study individually colour- and radiotagged coucals in the Usangu Plains, Tanzania.
Selected publications of the coucal project
21 (6), S. 1147 - 1155 (2010)DOIThreat signaling in female song-evidence from playbacks in a sex-role reversed bird species. Behavioral Ecology