All the latest in environmental issues
The purpose of zebra stripes
Zebra stripes are not for camoufl age. They probably are to
confuse biting fl ies, but new research indicates they may
also be for temperature control. The researchers collected
fi eld data from live zebras and found that during the
middle seven hours of the day the black stripes become
12–15°C hotter than the white. The diff erential
temperatures and air activity on the black and white
stripes set up small-scale convective air movements within
and just above the stripes — a zebra’s own personal breeze.
They also found that zebras have an unexpected ability to
raise the hair on their black stripes while the white ones
remain fl at. The researchers proposed that the raising of
black hairs during the heat of the day, when the stripes
were at diff erent temperatures, assisted with the transfer
of heat from the skin to the hair surface. Combined with
sweating, this is an eff ective cooling mechanism.
Source: Journal of Natural HistoryKoalas drinking in climate change
Koalas are particularly vulnerable to the
eff ects of climate change, suff ering both
from heat stress and because the trees
they rely on are aff ected by temperature
and rainfall change. A long-held view
has been that koalas get all their
hydration from eating leaves, but new
research has challenged that idea. The
researchers conducted fi eld work in
Gunnedah in western NSW, setting up
water stations and monitoring whether
koalas might visit them. During the fi rst
12 months of the study, researchers recorded
605 visits to 10 pairs of water stations, with
401 of these visits resulting in koalas drinking.
They found that the total number of visits and total
time drinking doubled during summer compared to other seasons. The stations
might also attract predators, but stations that are inaccessible to ground-based
predators might be a useful tool in helping koalas survives climate change.
Source: PLoS ONEThe nature dose
We know that spending time in
nature is good for your physical
and mental health. The question
is, how much time in nature is
an adequate dose? A new study
addressed this by analysing
data from nearly 20,000 people
in England, finding that people
who spend at least 120 minutes
a week in nature are significantly
more likely to report good
health and higher psychological
wellbeing than those who don’t
visit nature at all during an
average week. No benefits were
found for people who visited
natural settings such as town
parks, woodlands, country parks
and beaches for less than 120
minutes a week. It also found the
120-minute threshold applied to
both men and women, to older
and younger adults, across
different occupational and ethnic
groups, among those living in
both rich and poor areas, and
even among people with long-
term illnesses or disabilities.
So the nature dose for wellbeing
is two hours a week.
Source: Scientific Reports Photography^ GettyImagesThe carbon dioxide (CO 2 ) produced when fossil
fuels are burned is normally released into the
atmosphere and is a major greenhouse gas.
Researchers working on synthetic fuels, also
known as carbon-neutral fuels, are exploring
ways to capture and recycle that CO 2. Now,
researchers have successfully developed a high-
efficiency catalyst that converts dissolved CO 2 into
carbon monoxide (CO). Previously, most catalysts
have involved precious metals such as gold, but
these researchers have used a stabilised formof iron. Currently, most of the carbon monoxide
needed to make synthetic materials is obtained
from petroleum. Recycling the CO 2 produced by
burning fossil fuels into CO would help preserve
precious resources, as well as limit the amount
of CO 2 released into the atmosphere. The process
could also be combined with storage batteries
and hydrogen-production technologies to convert
surplus renewable power into products that
could fill the gap when demand outstrips supply.
Source: ScienceCarbon-neutral fuels
18 | wellbeing.com.au
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