What factors contribute to an ownership advantage?

Abstract

In most taxa, owners win fights when defending a territory against intruders. We calculated effect sizes for four factors that potentially contribute to an ‘owner advantage’. We studied male fiddler crabs Uca mjoebergi , where owners won 92% of natural fights. Owners were not more successful because they were inherently better fighters ( r =0.02). There was a small effect ( r =0.18) of the owner's knowledge of territory quality (food availability) and a medium effect ( r =0.29) of his having established relations with neighbours (duration of active tenure), but neither was statistically significant. There was, however, a significant effect due to the mechanical advantage the owner gained through access to the burrow during fights ( r =0.48, p <0.005).