Koalas hug trees to stay cool (6th June, 2014)
Scientists have
unlocked one of the secrets as to how koalas stay cool and avoid dehydration in
the intense heat of Australian summers. They hug trees. For decades people
thought the cuddly marsupials clung to trees simply because they were tired and
wanted somewhere to nap. Researchers from Melbourne University have now cast
new light on the tree-hugging habits of the koala. Lead researcher Natalie
Briscoe said there is a five-degree difference in temperature between a tree
trunk and the air. Koalas utilize the cooler surface by spreading themselves
out on large branches or by hugging the trunk. Ms. Briscoe said: "Access
to these trees can save about half the water a koala would need to keep cool on
a hot day."
Briscoe studied the
behaviour of 37 koalas on an island off the Melbourne coast. She is part of a
team trying to identify how koalas might survive higher temperatures brought by
global warming. Her observations and conclusions regarding the cooling effects
of the trees came as a surprise to her. She noted that the koalas sat upright
in cooler weather, hugged branches when it became warmer, and then wrapped
themselves around the tree trunk when it got hot. The animals even moved to
different trees that had cooler trunks. She said the trees are probably cooler
because of the water they suck up from the ground. The koala's cooling
technique could be one way for humans to survive increasingly hot summers.
MULTIPLE CHOICE -
QUIZ
1.
|
What have scientists done
to a secret?
|
6.
|
How many koalas did
researchers look at?
|
a) shared it
b) unlocked it c) kept it d) exposed it |
a) 37
b) 36 c) 35 d) 34 |
||
2.
|
For how long did people
think koalas hugged trees to sleep?
|
7.
|
How did the researcher
feel about the conclusions of the research?
|
a) 34 days
b) since 1812 c) decades d) millennia |
a) stunned
b) satisfied c) shocked d) surprised |
||
3.
|
What have researchers
cast on the koala's habits?
|
8.
|
Why did koalas move to
different trees?
|
a) nets
b) seeds c) doubt d) new light |
a) for food
b) because of ants c) they were cooler d) to get a change of scenery |
||
4.
|
What is the difference in
temperature between a tree trunk and the air?
|
9.
|
How do trees get water?
|
a) hot and cold
b) 5 degrees c) three fish d) the mercury is rising |
a) absorb it from rain
b) photosynthesis c) by osmosis d) they suck it up from the ground |
||
5.
|
How much water can koalas
save by hugging trees?
|
10.
|
What could humans survive
by using the koala's cooling technique?
|
a) half
b) 2 litres c) as much as they sweat d) a few drops an hour |
a) 30-minute saunas
b) hotter summers c) deforestation d) a eucalyptus shortage |
