A small Australian marsupial called "antechinus" sacrifices hours of sleep at night to dedicate more time to sex during the mating season. Males only reproduce once in their life and live one year, while females live two years.
The study does not clarify what causes the death of males after the breeding season, although the researchers do not believe that it is due solely to loss of sleep. The authors suggest that these animals may gain some advantage by sleeping less during this time, or they may accept the drawbacks of staying awake to improve their chances of parenting.