Time allocation in Canada geese during the breeding season

Abstrakti

The effect of breeding status and sex on time allocation in Canada Geese Branta canadensis during the breeding season was studied in 1988 in central Sweden. Time budgets were established during four parts of the breeding season: on the breeding grounds before egg-laying, during incubation, when the goslings were newly hatched and when the goslings were fledged or nearly fledged. Most differences in time allocation between categories and sexes were due to differences in energetically costly processes and in the demands of other types of behaviour than foraging, mainly vigilance. Prior to nesting, there were indications that the use of reserves could be important, at least for breeding females. The allocation of time to foraging prior to and during the moult by non-breeding geese suggested that during the moult they relied on energy reserves gained in the preceding period . Vigilance was the most common behaviour for breeding geese after the goslings had hatched. During the early broodrearing period, breeding females showed a weak tendency to be less vigilant and spend more time foraging than breeding males, though these differences were not statistically significant. When the goslings were fledged or nearly fledged, the time allocation of breeding females and males was almost identical. The proportion of time spent on vigilance by geese with goslings was not significantly correlated with the brood size .