Only the fittest cockroaches find a mate – study
Published: 9 December 2015 at 12:31
New research shows how energetic courtship displays attract female partners
Female cockroaches select only the fittest males to mate with, according to a new study published by the journal PLOS ONE.
The research, led by Dr Sophie Mowles of Anglia Ruskin University, investigated the courtship displays of the Cuban burrowing cockroach (Byrsotria fumigata).
Male Cuban burrowing cockroaches perform a “wing-raising” ritual to attract a female, which involves the repeated vertical flaring and lowering of their wings.
The scientists found the ones that produced the most energetic displays were more likely to attract a female. In fact males that did attract a mate performed the “wing-raising” on average four times more vigorously as the ones that didn’t.
And using a specially constructed racetrack, the scientists also conducted an experiment to measure the amount of energy expended during the “wing-raising” display.
The males that had taken part in the courtship display had depleted performance (lower top speeds and shorter distances covered) than males that had not taken part (control), demonstrating that courtship is energetically costly and depletes the stamina of the cockroaches.
Dr Mowles, Lecturer in Animal & Environmental Biology at Anglia Ruskin University, said:
“This is the first time these techniques have been used to demonstrate how a dynamic, repeated courtship display can affect future performance.
“Our experiments show that the courtship display significantly fatigues the male cockroach, and it’s the energy expended during the display, rather than other factors such as size of the male, that is used by females to inform their mating decisions.
“Signs of male stamina are clearly important to the females, presumably as it ensures they pass good genes on to their offspring.
“The females will want to ensure their offspring have high physical fitness, providing them with the ability to evade predators, defeat rivals and attract females themselves.”
The full open access article “Physiological Costs of Repetitive Courtship Displays in Cockroaches Handicap Locomotor Performance” can be read here.