Backwell, PatriciaMatsumasa, M.Double, MichaelRoberts, AlexanderMurai, MinoruKeogh, J ScottJennions, Michael2015-12-100962-8452http://hdl.handle.net/1885/39929Male fiddler crabs (genus Uca) have an enlarged major claw that is used during fights. In most species, 50% of males have a major claw on the left and 50% on the right. In Uca vocans vomeris, however, less than 1.4% of males are left-clawed. Fights between opponents with claws on the same or opposite side result in different physical alignment of claws, which affects fighting tactics. Left-clawed males mainly fight opposite-clawed opponents, so we predicted that they would be better fighters due to their relatively greater experience in fighting opposite-clawed opponents. We found, however, that (i) a left-clawed male retains a burrow for a significantly shorter period than a size-matched right-clawed male, (ii) when experimentally displaced from their burrow, there is no difference in the tactics used by left- and right-clawed males to obtain a new burrow; however, right-clawed males are significantly more likely to initiate fights with resident males, and (iii) right-clawed residents engage in significantly more fights than left-clawed residents. It appears that left-clawed males are actually less likely to fight, and when they do fight they are less likely to win, than right-clawed males. The low-level persistence of left-clawed males is therefore unlikely to involve a frequency-dependent advantage associated with fighting experience.Keywords: crab; fighting; functional morphology; intrasexual interaction; intraspecific competition; male; persistence; polymorphism; sexual selection; article; burrowing species; crab; experimental study; fighting; nonhuman; prediction; priority journal; Aggressio Frequency-dependent; Laterality; Male-male competition; Mate choice; Polymorphism; Sexual selectionWhat are the consequences of being left-clawed in a predominantly right-clawed fiddler crab?200710.1098/rspb.2007.06662015-12-09