AN ELEPHANT IN YOUR BACKYARD??

Ever since I was a kid, reading The Journals of Lewis & Clark, and George Catlin's journals, I have fantasied about seeing the American Plains with the herds of buffalo, elk, antelopes, and on and on. Going further back in time,  I would like to see the plains before the extinction of the megafauna.  Throw in some cloned mammoths, giant ground sloths, perhaps a Saber-tooth Cat or two.  It would certainly be interesting to have " Pleistocene (1.65 million until 10000 years ago)  Parks" in The Americas, and Australia. 

  AMERICAS NEED ELEPHANTS: ECOLOGIST SAYS

(AUSTRALIA TOO!!)

ABC AUSTRALIA - News In Science by Dani Cooper

In what sounds like a page from a Michael Crichton novel, an Australian ecologist has called for the introduction of elephants into South America and the creation of Pleistocene parks across the world.

Professor Chris Johnson, of  James Cook University, Far North Queensland, says the re-introduction of large herbivores to the Americas would help restore ecosystems and save threatened native species.

 

 

The experiment would also help settle the debate over whether humans or climate change caused megafauna, such as mammoths and giant kangaroos, to become extinct, he says.

In a literature review released today in The Proceedings of the Royal Society, the ecologist examines how the loss of giant herbivores about 50,000 years ago affected ecosystems.

Johnson, from James Cook University's School of Marine and Tropical Sciences, says the large animals maintained vegetation openness and in wooded landscapes created "mosaics" of different vegetation with a high diversity of plant species.

However, the extinction of megafauna saw landscapes very quickly, in ecological terms, become dense and uniform, he says.

Human-driven extinction

Johnson says his paper adds weight to the argument that humans, rather than climate change, were responsible for the extinction of mammals such as Australia's giant wombat, Diprotodon optatum.

"Any changes in vegetation that coincided with extinction are perhaps too readily attributed to changes in temperature, rainfall or atmospheric CO2," he says.

"This thinking has often gone further, to conclude that extinction of megafauna was a consequence of vegetation change, as if powerful creatures such as mammoths were helplessly subject to climate-driven changes shifts in environment."

Johnson says, "one of the things we know about large animals is they are very resilient".

"What's more sensible is to look at an African savannah and ask ourselves how does this change if we take out the elephants."

He says because the debate is driven by paleontologists and archaeologists they "haven't thought through the interaction between animals and plants".

Johnson points to studies that show vegetation changed after the giant plant eaters became extinct and not, as is required under the climate change scenario, before.

He points to studies of ancient emu eggshells that show more than 50,000 years ago the flightless bird had a broad diet that was a mixture of subtropical and arid grasses and shrubs, trees and temperate grasses.

 

"In Pleistocene times, giant 'megafauna' inhabited Australia. These animals mysteriously disappeared in Australia about 15,000 yearsago, including:

* the great rhinoceros-like Diprotodon,                                                                            

*the giant kangaroo standing 3 metres (10 feet) high
* a giant marsupial wombat
* Megalania, a goanna 6 metres (12 feet) long
* Quinkana, a land crocodile 3 metres long
* Wonambi, a python 7 metres long
* the flightless birds, Genyornis (giant emu) and Dromornis, which matched the great Moa in size"

Yet by about 45,000 years ago the bird's diet no longer included subtropical and arid grasses.

"It shows their foraging environment was once broad and diverse and that this contracted to a more uniform landscape," he says. "Climate cannot account for this change."

Evolutionary 'ghosts'

Johnson also points to "evolutionary ghosts" in the Australian landscape such as the endangered Acacia peuce tree that is found in isolated pockets in the Simpson Desert.

He says the plant has protective features that include a very prickly, ridged leaf that grew "up to the height of a diprotodon's nose". After that is has a soft, willowy, sweet leaf.

"The browse line is an evolutionary ghost" he says that shows the A. peuce had a defence mechanism against megafauna.

"If you look for those traits in Australian acacias [today] they are quite rare," he says, "whereas in African acacias they are ubiquitous."

Johnson says there are many plants that once interacted with the megafauna that still retain obsolete defences and ineffective methods of seed dispersal.

He says reintroduction of large herbivores to regions where these plants still exist could help save them.

He points to studies by US ecologist Daniel Janzen that shows feral horse populations are fulfilling the ecological role extinct native American horses once played.

"There are now some native plant species that rely on feral horses for seed dispersal," says Johnson.

He says reintroducing elephants to South America would have a similar impact on vegetation.

"They would walk into an ecosystem that is just waiting for them," he says.

Pleistocene park?

Johnson also believes the creation of Pleistocene parks, where the original large mammals or their closest analogues are reintroduced, is feasible and essential to conserve biodiversity.

"To understand living plant communities we need to re-imagine them with their full complement of Pleistocene megafauna," he says.

"This insight should also provide the foundation for ecological restoration, which should aim to reinstate interactions between large herbivores and vegetation where that is still possible."

 

Some further reading if you enjoyed the above article, John

A Russian plan for Siberia from 2005:  http://news.bbc.co.uk/2/hi/science/nature/4533485.stm

And a section from the book: THE WORLD WITHOUT US by Alan Weisman, (I highly recommend the book; and Discovery Channel did a series based on the book) this is a  really interesting section dealing with the parks in Kenya, and how the Masai and their cattle used to be in balance with the herds of elephants and other wildlife, but that has changed with the parks shrinking:  http://www.theglobalist.com/storyid.aspx?StoryId=6629