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 Scientists have now taken a bit of a look under the hood of these
feline Ferraris to gauge how much energy they burn as they traverse
their African habitats and to gain insight into factors that may be
contributing to their precipitous population plunge.
A study published on Thursday in the journal Science described how
researchers tracked 19 free-roaming cheetahs for two weeks at two
sites in South Africa and Botswana. They measured energy expenditure
after injecting cheetahs with isotope-laden water and later
analyzing their feces.
They were surprised to learn that cheetahs used relatively little
energy in their high-speed chases for prey like gazelles and
impalas. The world's fastest land mammals, known for their spotted
coat, cheetahs accelerate from a standstill to 60 mph (96 kph) in
three seconds in amazing short bursts of speed.
"Our data suggest that they are indeed perfectly adapted to this
hunting technique. They recover pretty fast, so the high-speed
hunting doesn't really affect their quality of life," said one of
the researchers, North Carolina State University biologist Johnny
Wilson.
The findings also contradicted the hypothesis that cheetahs expend
an inordinate amount of energy catching new prey after bigger
competing predators like lions and hyenas steal carcasses brought
down by them.
Their biggest energy drain was the distances cheetahs must walk
while seeking prey thanks to man-made problems like habitat loss in
grasslands and other areas, fences restricting free travel and
people killing too many of the animals cheetahs eat.
Queen's University Belfast biologist Michael Scantlebury, who led
the study, said the cheetahs traveled up to nearly 19 miles (30 km)
per day. He said "cheetahs may be Ferraris but most of the time they
are driving slowly," traipsing over sand dunes in baking heat with
no water to drink.
Cheetah populations have declined from about 100,000 to 10,000 over
the past century, experts say.
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"It is us humans that are going to be responsible for their
dwindling numbers. We need to be even more careful to look after and
maintain the remaining areas of the world that are truly wild, and
we need to think about the consequences of our actions," Scantlebury
said.
Another study in the same journal used a different approach to
assess energy expenditure in another big cat, the mountain lion of
the Americas, also known as a puma or cougar.
Scientists studied energy expenditure by mountain lions by somehow
putting some on treadmills. They then used a special tracking collar
to monitor their movements in the wild. Mountain lions do not use
speed, but use an energy-conserving sneak attack with a lethal
pounce.
"The more time that the animals could spend in low-activity level
behaviors - stalking, sit-and-waiting, slow walking - the greater
the relative benefit of the kill, basically less calories expended
for obtaining prey calories," said University of California-Santa
Cruz wildlife physiologist Terrie Williams.
(Reporting by Will Dunham; Editing by Tom Brown)
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