Collective pooling of foraging information in animal fission-fusion dynamics

1In animal species with fission-fusion dynamics, individuals can split from or follow others during collective movements. In spider monkeys (Ateles geoffroyi) this decision depends in part on the information they have about the location of available feeding trees. Foraging widely and continuously splitting and joining from others, individuals could be pooling their partial information such that the group as a whole has a more complete picture of a heterogeneous foraging environment. Here we use individual utilization areas over a realistic foraging landscape to infer the sets of potentially known trees by each individual. Then we measure the spatial entropy of these areas, considering tree species diversity and spatial distribution. We measure how complementary pairs of areas are, by decomposing the spatial entropy into redundant and unique components. We find that the areas uniquely known by each pair member still contain considerable amounts of information, but there is also a high redundancy in the information that a pair has about the foraging landscape. The networks joining individuals based on the unique information components seem to be structured efficiently for information transmission. Distributed foraging in fission-fusion dynamics would be an example of adaptive pooling of information and thus, collective intelligence.