Data from: Contest dynamics and assessment strategies in combatant monkey beetles (Scarabaeidae: Hopliini)

Some of the most striking examples of intrasexual contest competition are
to be found in the insects, whose weaponry and contest behaviours have
become highly intricate and diverse. Game theory has been used as a basis
to develop models of the competitive assessment strategies that may be
used by males to either judge their probability of winning by comparing
their own fighting ability to that of their opponents, or to persist in
contests for a period determined only by their own fighting ability.
Conclusions from empirical studies about the means of assessment in their
study systems have not, however, always been clear. In view of this, some
authors have suggested that utilizing a broad suite of data concerning
multiple facets of the study system may assist in gaining clearer insights
into animal contests and assessment strategies. The present study
integrates data on contest behaviour, weapon morphology, residency
effects, cost accumulation, and correlates of contest success, to test
game theory-informed models of competitive assessment strategies in the
sexually dimorphic monkey beetle Heterochelus chiragricus. We found that
males of all sizes engaged aggressively in intrasexual contests for mating
access to sedentary females, utilizing their hypertrophied hind legs as
weapons. Contest outcome was determined by hind femur size and strongly
influenced by residency effects. We found mixed support for both pure
self-assessment and mutual assessment contest strategies. Such
inconclusive findings are not uncommon in animal contest assessment
studies, even when contest cost and RHP data are contextualized with
behavioural and ecological data.