Intragroup competition predicts individual foraging specialisation in a group-living mammal
Wiley for Centre National de la Recherche Scientifique (CNRS)
©2018 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use,distribution and reproduction in any medium, provided the original work is properly cited
Individual foraging specialisation has important ecological implications, but its causes in group-living species are unclear. One of the major consequences of group living is increased intragroup competition for resources. Foraging theory predicts that with increased competition, individuals should add new prey items to their diet, widening their foraging niche (‘optimal foraging hypothesis’). However, classic competition theory suggests the opposite: that increased competition leads to niche partitioning and greater individual foraging specialisation (‘niche partitioning hypothesis’). We tested these opposing predictions in wild, group-living banded mongooses (Mungos mungo), using stable isotope analysis of banded mongoose whiskers to quantify individual and group foraging niche. Individual foraging niche size declined with increasing group size, despite all groups having a similar overall niche size. Our findings support the prediction that competition promotes niche partitioning within social groups and suggest that individual foraging specialisation may play an important role in the formation of stable social groupings.
The research was funded by a European Research Council Starting Grant (309249) and Natural Environment Research Council (UK) Standard Grant (NE/J010278/1) awarded to MAC.
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record
Published online 14 March 2018