In a recent paper from Behavioural Ecology, the Emlen lab examines the cost of male ornamentation of the Japanese rhinoceros beetle (Trypoxylus dichotomus) on flight. (click here for the link to the full article) Sexual selected traits such as horn size are expected to pose significant fitness costs to the males as has been previously discussed. In this study, the author found that male flight in terms of speed and distance was no different from females and there was also no difference among males morphs. Oh wait…did I mention they used radiotelemetry on beetles??!!! They fit the beetles with mega-tiny radio transmitters!
This study also measured compensatory morphological traits and found that increased horn size was linked to larger wing size as well as greater flight muscle mass.
This paper is definitely worth a read and the authors offer a few interesting explanations for failing to observe differences in flight speed and distance among male morph and compared to females.