Comparative Statistical and Information Analysis of Combat in the Fiddler Crabs, Uca Pugilator and U. Pugnax

Statistical and information theory analyses were performed with data derived from the aggressive interactions of two temperate species of fiddler crabs (Uca pugilator and U. pugnax). Over 400 fights were observed for each species, in their natural habitats. The two species showed differences in the distributions of their aggressive acts and in the average number of acts performed during combat. Many acts were statistically linked in ways which align meaningfully with the contribution of aggressiveness to the survival of the animals. Information analysis showed quantitative differences in uncertainty measures, but the efficiency of their communication systems, i.e., the amount of information transmitted, remained the same between combatants of each species. An interesting finding is the relative difference (about 15%) in intraspecific normalized transmission values which occur between Resident and Wanderer. We suggest that this role-specific relationship can be addressed by hypothesizing the optimum strategies that would tend to maximize the combatant's burrow-holding potential, while minimizing the penalties for losing a burrow.