title: Adaptive collective foraging in groups with conflicting nutritional needs.
abstract: Collective foraging, based on positive feedback and quorum responses, is believed to improve the foraging efficiency of animals. Nutritional models suggest that social information transfer increases the ability of foragers with closely aligned nutritional needs to find nutrients and maintain a balanced diet. However, whether or not collective foraging is adaptive in a heterogeneous group composed of individuals with differing nutritional needs is virtually unexplored. Here we develop an evolutionary agent-based model using concepts of nutritional ecology to address this knowledge gap. Our aim was to evaluate how collective foraging, mediated by social retention on foods, can improve nutrient balancing in individuals with different requirements. The model suggests that in groups where inter-individual nutritional needs are unimodally distributed, high levels of collective foraging yield optimal individual fitness by reducing search times that result from moving between nutritionally imbalanced foods. However, where nutritional needs are highly bimodal (e.g. where the requirements of males and females differ) collective foraging is selected against, leading to group fission. In this case, additional mechanisms such as assortative interactions can coevolve to allow collective foraging by subgroups of individuals with aligned requirements. Our findings indicate that collective foraging is an efficient strategy for nutrient regulation in animals inhabiting complex nutritional environments and exhibiting a range of social forms.
authors.affiliation: Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia; School of Mathematics and Statistics, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Alistair M
authors.initials: AM
authors.lastname: Senior
authors.affiliation: Research Center on Animal Cognition (CRCA) , Center for Integrative Biology (CBI), Toulouse University , CNRS , UPS, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Lihoreau
authors.affiliation: School of Physical Sciences , University of Tasmania , Hobart, Tasmania 7005 , Australia.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Charleston
authors.affiliation: School of Agriculture, Food and Wine , The University of Adelaide , Adelaide, South Australia 5005 , Australia.
authors.forename: Jerome
authors.initials: J
authors.lastname: Buhl
authors.affiliation: Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Faculty of Veterinary Science, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Raubenheimer
authors.affiliation: Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Simpson
keywords: collective decisions; foraging; individual-based model; nutritional geometry; social interactions; sociality