Asymmetric contests over resources for survival and migration: a field experiment with bluethroats
The relative importance of prior occupancy and of asymmetries in both value of winning and in resource-holding potential for the outcome of animal contests was tested. Bluethroats, Luscinia s. svecica, were offered food ad libitum in the field. Prior to migration, at a moulting site, their weight increased rapidly and peaked after a few days. Lean birds won significantly more interactions than fat
