Playing the field can be deadly, at least for crickets. Research published today in the journal Nature indicates that well-fed casanova crickets spend so much energy on mating calls to court female partners that they die sooner than malnourished males do.
John Hunt of the University of New South Wales in Australia and his colleagues observed two groups of field crickets. One group ate a restrictive, low-protein diet whereas the other dined on protein-rich foods. The researchers monitored the creatures' size, mating behavior and how long they lived. For female crickets, those fed a robust diet lived longer than did their protein-starved counterparts. This pattern did not hold for the males, however. Instead, the well-fed males used their extra energy to woo female partners by calling more extensively during early adulthood and experienced shortened life spans as a result. "They literally knocked themselves out trying to impress female crickets," says study co-author Luc F. Bussiere, also at the University of New South Wales.
The findings demonstrate that the best reproductive strategy in the animal kingdom does not always coincide with living a long life. What is more, long-lived males are not necessarily those in the best condition, which indicates that longevity is not always a reliable measure of male quality. "One thing that consistently prolongs life span in a range of species is a restricted diet," remarks co-author Rob Brooks of the University of New South Wales. "Now we know a bit more about how this occurs in male crickets--by suppressing sexual advertisement."