Moreno J. (1989) Energetic constraints on uniparental incubation in the Wheatear Oenanthe oenanthe. ARDEA 77 (1): 107-115

The incubation behavior of Wheatears Oenanthe oenanthe was studied during 3 years in the island of Oland, S. Sweden. Breeding females which got additional food were compared with 'normal' females in order to test whether the female attentiveness was constrained by energetic requirements. Provisioned females took shorter foraging recesses but did not increase length of the time spend in the nest. During the coldest year, there was a positive correlation between the amount of supplementary food and attentiveness. The length of incubation periods was also negatively affected during that year by the amount of food offered. No marked effect of food provisioning on hatching success was observed. The pattern of incubation in the Wheatear seems constrained by the energy requirements of females.