Teen elephant mothers die younger but have bigger families, study finds

March 7, 2014
A male Asian elephant in the wild at Bandipur National Park in India. Credit: Yathin S Krishnappa/Wikipedia

Asian elephants that give birth as teenagers die younger than older mothers but raise bigger families during their lifetime, according to new research from the University of Sheffield.

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, that entered motherhood at an earlier age had more calves following their teenage years than those that started reproducing after the age of 19.

The team's findings will help maximise fertility in captive and semi-captive elephants, reducing the strain on the endangered wild population.

Research found that Asian elephants, which can live into their 70s, could give birth from the age of five.

Yet surprisingly, for a species that live as long as humans do, their fertility peaked on average at the age of 19 before declining.

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 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.

Dr Adam Hayward, of the University of Sheffield's Department of Animal and Plant Sciences, said: "Understanding how maternal performance changes with age and impacts on later-life survival and fertility is important. Asian elephants are endangered in the wild and low fertility in captivity necessitates acquisition of elephants from the wild every year to maintain captive populations.

"Our research was carried out on semi-captive Asian elephants working in timber camps in Myanmar.

"As religious icons in South-east Asia and a key species of the forest ecosystem, their decline is of serious cultural and ecological concern.

"Our results will enable the management of captive and semi-captive elephants to be tailored to maximise fertility, reducing strain on the wild population."

Virpi Lummaa, Reader of Evolutionary Biology at the University of Sheffield, added: "We rarely get the opportunity to study how other species with a lifespan similar to humans grow old.

"This study represents a unique analysis of the ageing process in a similarly long-lived mammal.

"It also supports the evolutionary theory that selection for in early life is energetically demanding, which accelerates declines in survival rates with which are typical of most animals."

Explore further: Climate change endangers elephants, study says

Related Stories

Climate change endangers elephants, study says

January 28, 2013

By making new use of historical records, scientists have shown that climate change could have a greater impact on Myanmar's elephants' dwindling numbers than previously thought.

Thai tourist industry 'driving' elephant smuggling

March 2, 2013

Smuggling the world's largest land animal across an international border sounds like a mammoth undertaking, but activists say that does not stop traffickers supplying Asian elephants to Thai tourist attractions.

Deadly virus threatens endangered elephants

June 17, 2013

(Phys.org) —Researchers are racing the clock to better understand a deadly virus which has the potential to intensify population declines in the endangered Asian elephant.

Thai police seize 16 'illegal' elephants

August 21, 2013

Thai police said Wednesday they had seized 16 elephants from tourist destinations as part of a nationwide swoop on operators suspected of using smuggled wild pachyderms for entertainment.

Asian elephants reassure others in distress

February 18, 2014

Asian elephants console others who are in distress, using physical touches and vocalizations, finds a study to be published in the open access journal PeerJ. The findings are the first empirical evidence of consolation in ...

Elephant age estimated from voice

March 6, 2014

A paper published in Bioacoustics explains how researchers have been able to estimate the age of an elephant based on its vocal sounds. Results showed that they could distinguish infants, calves, juveniles, and adults with ...

Recommended for you

Study suggests fish can experience 'emotional fever'

November 25, 2015

(Phys.org)—A small team of researchers from the U.K. and Spain has found via lab study that at least one type of fish is capable of experiencing 'emotional fever,' which suggests it may qualify as a sentient being. In their ...

A huge chunk of a tardigrade's genome comes from foreign DNA

November 23, 2015

Researchers from the University of North Carolina at Chapel Hill have sequenced the genome of the nearly indestructible tardigrade, the only animal known to survive the extreme environment of outer space, and found something ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.