Researchers have found that Asian elephants that give birth as teenagers die younger than older mothers but raise bigger families during their lifetime.
Experts from the University's Department of Animal and Plant Sciences studied the reproductive lives of 416 Asian elephant mothers in Myanmar, Burma, and found those that had calves before the age of 19 were almost two times more likely to die before the age of 50 than those that had their first offspring later.
However, elephants that entered motherhood at an earlier age had more calves following their teenage years than those that started reproducing after the age of 19.
Research found that Asian elephants, which can live into their 70s, could give birth from the age of five.
The team also found elephants that gave birth twice in their teenage years had calves three times more likely to survive to independence than those born to mothers who had their first young after the age of 19.
Therefore, although having calves as a teenager reduced a mother's lifespan, early reproduction was favoured by natural selection because those mothers raised the largest families in their lifetime.
The study has been published in the Journal of Evolutionary Biology.