Size-biased foraging behaviour in feral cattle

The foraging behaviour of a feral cattle population in southwest Spain was studied. Descriptive variables of intake behaviour (i.e. bite rate, step rate and bite/step ratio) were influenced both by extrinsic factors (food abundance and type of plant community) and by an intrinsic factor (individual body size). The type of plant community decisively influenced the grazing behaviour of animals. Food abundance affected the foraging behaviour, but was not independent from the type of plant community. Body size influenced the foraging behaviour depending on the level of food availability. Small and medium-sized animals (juveniles, sub-adults and adult females) were more selective in their diet than larger animals (adult males) and changed their foraging behaviour according to the level of food abundance in order to maintain intakes of preferred food. Differences in foraging behaviour among size classes could be related to the sexual segregation between adult males and females out of the rutting period.