BBC_Knowledge_2014-06_Asia_100p

into a much smaller time frame, and koalas simply aren’t

able to adapt.”

Climate change means a build-up of carbon dioxide in

the atmosphere, which has an impact on leaf chemistry.

While it speeds up growth, it does so at the expense of

nutrients, increasing the toxins that the koala’s large ‘super

liver’ has already adapted to deal with.

Christine’s research has shown that koalas can’t survive

in persistent temperatures over 37.7ºC. They already work

hard to avoid heat, often taking to specific ‘shade trees’

during the day, and climbing into food trees in the cool of

the night to browse. “They can cope with the odd hot day,”

explains Christine, “but they can’t deal with the protracted

heat waves that are we are starting to see, where we get

temperatures over 40ºC for a week at a time. Researchers

noticed this in the 1980s when, after long hot periods,

koalas just fell out of the trees and died. During the 2008–9

drought, eucalypt leaves dried so much that the animals

weren’t getting the moisture or nutrition they needed from

the leaves, and they struggled to thermoregulate.”

Political success

More than 20 years of campaigning led to Australia’s

Labour government awarding the status of ‘Vulnerable’

to koalas in Queensland and New South Wales.

Translating this into action that addresses the problems

faced by urban koalas is tough, but Christine would like

to see important climate refugia identified and protected.

“The situation is just going to get worse,” she explains.

“Inland Queensland and New South Wales are going to

become hotter and drier, so they will lose their food trees.

Between 1990 and 2009 we found an 80 per cent decline

in koalas around the western parts of these areas. As you

move to the coast it gets cooler with more rainfall, so our

modelling shows that these will be the key refuge areas

for koalas.”

While Christine views this as a realistic and proactive

approach that could get the most from limited political

action, scientists – including AKF chief ecologist Douglas

Kerlin – feel it could simply lead to more urbanisation.

“Focusing on climate refugia means we’re not planning for

recovery of the species but just trying to hold on as long as

possible,” he says. “I’m concerned that the idea is being used

by some people to open up the rest of the country

to development.”

And with Labour now in opposition following an

election in September 2013, political change is seen as

cause for concern. “The new state premier of Queensland,

1930

President Hoover bans the

import of koala skins into the

US, effectively extinguishing

demand and bringing the end to

koala hunting.

POST–WWII

Tourism to Australia

increases and koalas are

exported to zoos overseas,

as the animal’s international

popularity rises.

1934

Frederick Lewis, the chief inspector of

game, says that the formerly abundant

animal is nearly extinct in the state

of Victoria, estimating that only

500 – 1,000 remain.

1924

With koalas extinct in Victoria and South

Australia, authorities start trans-

locations from small populations on

French Island and Phillip Island back to

the mainland.

KOALA TIMELINE SINCE EUROPEAN SETTLEMENT

RIGHT: there

are 600 types

of eucalypt in

Australia, but in

each area koalas

browse on

just a handful

of varieties

BELOW: koalas in

urban environments

are more likely

to show signs of

chlamydia infection

Poster: KJ Historical/Corbis

KOALAS