cows vs. elephants

[Guest guest]

Here is yet another sad story how meat eating is affecting wonderful wild animals, through cattle grazing and global warming. The key quotes are: "The study shows how the elephants lost out to cattle grazing on grasses. " and As we have global climate change [which cows significantly contribute to], that's going to

change the available resources. As you have populations increase - and

all African populations are increasing dramatically - then you'll have

more competition for the resources".Peace, Dan

 

Elephant hair reveals competition

 

 

 

By Jason Palmer

 

Science and technology reporter, BBC News

 

 

 

 

 

The diet and behaviour of elephants evidenced by the chemical makeup of

their tail hairs shows how they compete with other species, researchers

say.

The six-year study,

published in Proceedings of the National Academy of Sciences, followed

a single family of elephants in northern Kenya.

The study shows how the elephants lost out to cattle grazing on grasses.

It also shows the rate of conception rising as food and water resources become more abundant each year.

The study is part of an ongoing research programme tracking the

elephant family using GPS receivers on each individual and determining

a dietary history from their tail hairs. That history is laid out chronologically in an "isotope

record" along the hair. Isotopes are naturally occurring variations of

atoms that are chemically identical but have a slightly different mass.

Different food or water sources that the elephants might

access contain different ratios of isotopes of carbon, hydrogen or

nitrogen. The team's prior work in 2006 showed the power of the

maxim "you are what you eat"; a clear record of the elephants' diets

was evident in the proteins that made up their tail hairs.

 

'Out-competed'

 

“

 

You have to worry about the conflict of how humans want to use resources and how wildlife wants to use resources

 

â€

 

Thure Cerling

 

"Now, we have a long-term record so we can really see what one normal

family is doing over a long period of time," said Thure Cerling, the

University of Utah professor who leads the research. In the new work, the team also analysed the content of

deuterium - an isotope of hydrogen - in the elephants' tails to

determine the source of the water they drink. "During the dry season, the river they're accessing

comes from quite far away, so the water has had a lot of time to

evaporate and change its isotope composition," Professor Cerling told

BBC News. "Then during the rainy season, the rivers come up and

the whole isotope composition changes and we're able to actually see

that." But the surprise finding came from one season in which

the elephants apparently did not eat grasses that should have been

readily available. "When the rainy season comes you get this big sprouting

of grasses, but they can't access it until it is 30 to 50 centimetres

high," Professor Cerling said. "It's got to grow tall enough before

they can actually yank it off with their trunks. "We have this one incident where they apparently missed

an entire good season of grass resource; the GPS data shows that they

were outside [samburu National Reserve] in a community area where it

appears that they had to compete with cattle.

"They got out-competed in that situation."

The team also noted that conceptions rose sharply just a few weeks

after the rainy season brought abundant food and water. "They bulk up during the rainy season, get into good

condition, right as things are starting to get good," Professor Cerling

explained. What is more, the elephants' 22-month gestation period

means that the maximum birthing period is shortly before things get

good again. "That's right when they have adequate water and just

about the right time to access this high-protein grass source," he

added.

 

Future conflicts

 

 

The approach gives an intimate look into the elephants' behaviour and

diet in a way that traditionally could not be done. While that is of

tremendous academic interest to wildlife ecologists, Professor Cerling

says the recent findings point to an imminent problem of broader

interest. "It points out you have to worry about the conflict of

how humans want to use resources and how wildlife wants to use

resources," he says. "As we have global climate change, that's going to

change the available resources. As you have populations increase - and

all African populations are increasing dramatically - then you'll have

more competition for the resources.

"If you're concerned about preservation of wildlife then you have to worry about that competition." Story from BBC NEWS:

http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/7992786.stm

 

Published: 2009/04/13 23:24:07 GMT

 

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