Hyper-dispersed cache distributions reduce pilferage: a laboratory study

Abstract

L. H. Male and T. V. Smulders (correspondence), Newcastle University, Centre for Behaviour and Evolution, Henry Wellcome Building,Framlington Place, Newcastle upon Tyne, NE21 4HH, UK. E-mail: tom.smulders@ncl.ac.ukMany animals use hoarding as a long-term strategy to ensure a food supply at times of shortage. We suggest that long-term scatter hoarders, whose caches are vulnerable to potentially high pilferage, should hoard in ways to reduce cache loss.This could be achieved by manipulating the density and dispersal patterns of caches to reduce the foraging efficiency ofpilferers. This study explores the effect of distribution patterns on cache loss in the laboratory. We recorded the discoveryof food items in different dispersal patterns by two bird species: coal tits Periparus ater (a hoarder) and great tits Parusmajor (a non-hoarder). Hyper-dispersed distributions reduced foraging efficiency because both species used systematiclocal search patterns. This study shows that hyper-dispersed distributions would be advantageous to hoarding animals toreduce cache loss.