An individual's gain in a foraging group

By modelling an individual's gain through waiting times between subsequent prey encounters we characterise its performance when foraging alone or in a group. The larger the group, the longer the time between successful prey c aptures. The waiting times also depend on how the grouping behaviour affect s foraging efficiency of individuals, when joining a group. With full addit ivity (A = 1) grouping has no effect on an individual's foraging efficiency , while with larger values of additivity individuals co-operate. When A is below one subadditivity occurs and individuals interfere each other when fo raging in the patch. With A < 0 competition in the group is so hard that th e intake-rate for the group is less than the rate of gain of a solitary for ager. When additivity equals zero the patch corresponds to a system with co ntinuous input and immediate consumption of the arriving prey items. The mo del, via waiting times, renders it possible to examine different foraging s cenarios. For example, assuming that the forager already has gained k prey, for solitary foragers waiting times for the (k + 1)(th) prey are not affec ted by time in the patch, whereas for an individual in a group the waiting times get longer with increasing time. This is because other individuals af fect the prey availability by their foraging activity. Using the model we w ere able to uncover that in depleting patches under resource matching distr ibution of foragers food-intake rates of individuals differed in groups of different size. Finally, via modification of waiting times the finder's adv antage (the gain accumulated before others in the group arrive) can be impl emented into group foraging.