Size matters: preventing large mammal extinction

July 21, 2005

Saving large mammals such as elephants and rhino from extinction could be made more effective by focusing efforts on individual species as well as their habitats.
Scientists at the Zoological Society of London’s Institute of Zoology (IoZ) and Imperial College London have identified fundamental new approaches to improve the success of large mammal conservation. Published today in the journal Science, the largest study of its kind analyses key factors linked to the extinction of mammals.

“Conservation biologists have always known that large bodied mammals are at greater risk of extinction,” comments Professor Georgina Mace of the IoZ, “Now we understand the mechanisms, we are able to tailor conservation programmes dependant on size, to ensure they’re more effective.”

The study showed that extinction risk in smaller mammals, below approximately 3kg (about the weight of a small domestic cat), is determined primarily by the size and locations of their distributions, and the human impact to which they are exposed. Larger mammals have the additional pressure of biological disadvantages such as long gestation period and late weaning age to contend with, significantly increasing their susceptibility to extinction.

“In a world dominated by people, being big is substantially more of a disadvantage than we realised, which implies that the conservation of large mammals should assume a particular urgency,” said Dr Marcel Cardillo of Imperial College London.

“From a conservation policy angle, the message would be: small may be conservable but it is a little trickier for the larger mammals,” commented Dr Andy Purvis of Imperial College London.

The research findings suggest smaller species, of around less than 3kg, would benefit from conservation of their habitat area, whereas, larger bodied animals require a different approach, focusing upon the specific species, their biology and their habitat.

“This understanding enables us to predict what species are most at risk in the future,” said Dr Purvis. “That provides a way for conservationists to go on the front foot rather than wait for accidents to happen. We can try to work out which species are the ones we can do something for, and do some pre-emptive conservation planning. Of course, prevention is always cheaper than cure.”

The research means large bodied mammals such as ungulates (which include rhino and zebra) and many primates are more likely to be predisposed to decline and extinction.

Biological traits such as low population density, slow life history, late weaning age and extended gestation in mammals above a certain size means they are evolutionarily disadvantaged in the face of human impact, compared to species of smaller size. Large mammals may therefore need a more complex conservation strategy, which takes into account their biology in combination with the external threats they face.

Source: Zoological Society of London (ZSL)

Explore further: Scientists predict extinction risk for hard-to-track species

Related Stories

Scientists predict extinction risk for hard-to-track species

September 20, 2018

Species are going extinct all over the world: Scientists believe that Earth is losing between 200 and 2,000 species every year. That number is squishy, partly because there are so many species for which they lack good data—particularly ...

Recommended for you

What's behind the color and pattern of bird feathers?

September 26, 2018

While it may be true, as the old adage goes, that 'birds of a feather flock together,' what is less certain is how the feathers on those birds come to have their distinct patterns and colorations. Current data suggest that ...

The origins of the High Plains landscape

September 26, 2018

Starting at the eastern foot of the Rocky Mountains in the Midwest United States, the dramatic landscape of the High Plains stretches across several U.S. states. Dropping just a few hundred meters over a length of more than ...

A mechanism of color pattern formation in ladybird beetles

September 26, 2018

Many ladybirds have attractive color patterns consisting of black and red. This prominent color pattern is thought to function as a warning that indicates to predators that they are very bitter and unpalatable. A research ...

Zika and yellow fever—vaccines without eggs

September 26, 2018

A team led by researchers from the Max Planck Institute for Dynamics of Complex Technical Systems in Magdeburg is developing methods with which viruses for vaccines can be replicated in significantly higher concentrations ...

0 comments

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.