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, 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.
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 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.
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 high fertility in early life is energetically demanding, which accelerates declines in survival rates with age which are typical of most animals."
The study of elephants, which lived between the 1940s and the present day, was funded by the NERC and the Leverhulme Trust and is published today in the Journal of Evolutionary Biology.
Notes to editors:
The University of Sheffield
With almost 25,000 of the brightest students from around 120 countries, learning alongside over 1,200 of the best academics from across the globe, the University of Sheffield is one of the world's leading universities.
A member of the UK's prestigious Russell Group of leading research-led institutions, Sheffield offers world-class teaching and research excellence across a wide range of disciplines. Unified by the power of discovery and understanding, staff and students at the university are committed to finding new ways to transform the world we live in.
In 2011 it was named University of the Year in the Times Higher Education Awards and in the last decade has won four Queen's Anniversary Prizes in recognition of the outstanding contribution to the United Kingdom's intellectual, economic, cultural and social life.
Sheffield has five Nobel Prize winners among former staff and students and its alumni go on to hold positions of great responsibility and influence all over the world, making significant contributions in their chosen fields.
Global research partners and clients include Boeing, Rolls-Royce, Unilever, AstraZeneca, Glaxo SmithKline and Siemens, as well as many UK and overseas government agencies and charitable foundations.
For further information, please visit http://www.sheffield.ac.uk
For further information please contact: Hannah Postles, Media Relations Officer, on 0114 222 1046 or email firstname.lastname@example.org
To read other news releases about the University of Sheffield, visit http://www.sheffield.ac.uk/news
Hannah Postles | EurekAlert!
Magic number colloidal clusters
13.12.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
Record levels of mercury released by thawing permafrost in Canadian Arctic
13.12.2018 | University of Alberta
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
13.12.2018 | Life Sciences
13.12.2018 | Physics and Astronomy
13.12.2018 | Earth Sciences