Disentangling the effects of group size and density on shoaling decisions of three-spined sticklebacks (<Emphasis Type="Italic">Gasterosteus aculeatus</Emphasis>)
(1) Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121 Bonn, Germany;(2) Konrad Lorenz Institute for Ethology, Austrian Academy of Sciences, Savoyenstr. 1a, 1160 Vienna, Austria