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Topic: Megafauna


In the News (Sun 13 Apr 14)

  
  Megafauna extinction — people theory
Megafauna became extinct up to 50,000 years ago in Australia and New Guinea, around 10,900 years ago in North (and presumably South) America, about 1500 years ago in Madagascar, and between 900 and 600 years ago in New Zealand.
Secondly, megafauna are the biggest and slowest animals in the environment.
The other theory of megafauna extinction that is based on climate change must argue that extinction could have happened at almost any time in the last 50,000 years, whether the climate has been warm and wet or cold and dry, or any combination in between.
www.amonline.net.au /factsheets/megafauna_extinction.htm   (380 words)

  
 Megafauna extinction — patterns of extinction
The extinction of megafauna around the world was probably due to environmental and ecological factors.
It is believed that megafauna initially came into existence in response to glacial conditions and became extinct with the onset of warmer climates.
In temperate Eurasia and North America, megafauna extinction concluded simultaneously with the replacement of the vast periglacial tundra by an immense area of forest.
www.amonline.net.au /factsheets/megafauna.htm   (457 words)

  
 Megafauna - Wikipedia, the free encyclopedia
Megafauna are generally defined as animals that weigh over 500 kg to 1 tonne, i.e., any animal larger than the largest widespread domestic animal, the domestic bull.
Megafauna animals are generally K-strategists, with great longevity, slow population growth rates, low death rates, and few or no natural predators capable of killing adults.
Many species of megafauna have become extinct within the last million years, and, although some biologists dispute it, human hunting is often cited as the cause.
en.wikipedia.org /wiki/Megafauna   (448 words)

  
 Cuddie Springs: Archaeology, Univ. of Sydney
Investigations reveal a stratified deposit of human occupation and fossil megafauna, suggesting a temporal overlap and an active association of megafauna with people in the lead up to the last Glacial Maximum, when conditions were more arid than the present day.
Megafauna appear to be just one of a range of food resources exploited during this time.
Disappearance of megafauna is likely to be a consequence of climatic change during the lead up to the last Glacial Maximum and human activities may have compounded an extinction process well under way.
acl.arts.usyd.edu.au /research/cuddie/cuddie.html   (1745 words)

  
 Death of the Megafauna - Features - The Lab - Australian Broadcasting Corporation's Gateway to Science
There are many theories as to why the megafauna became extinct, but two simplistic and hotly-contested ones are the 'blitzkrieg' model, and climatic change.
Some scientists believe that the extinction of the megafauna in Australia was either caused by a 'blitzkrieg' of human-induced extinction, or through disruption of the ecosystem by humans.
One reason that discovering what caused the death of the megafauna is difficult, is the lack of exact methods of dating.
www.abc.net.au /science/features/megafauna/default.htm   (1066 words)

  
 Megafauna
The large animals of any particular area or time are its megafauna.
The term "charismatic megafauna" refers to animals that have great popular appeal: for example, the Giant Panda, the Red Wolf, the Blue Whale or the Koala.
Charismatic megafauna often garner a disproportionate level of public concern.
www.ebroadcast.com.au /lookup/encyclopedia/me/Megafauna.html   (254 words)

  
 Mammals - Fossil Mammals - Lost Giants
However, for the first Australians, there is no smoking gun in the form of murdered megafauna, there are no specialised weapons, and their immediate ancestors were almost certainly not systematic hunters of big animals.
dated six sites with megafauna at significantly less than 46,000 years old, yet they dismissed them, based on the grounds that they were more likely to have been disturbed because they didn't contain skeletal material in neat, anatomically correct positions.
Megafauna probably persisted longest in ever-shrinking wetter regions, especially toward the coast.
www.amonline.net.au /mammals/fossil/lost_giants.htm   (2737 words)

  
 Pleistocene megafauna - Wikipedia, the free encyclopedia
Pleistocene megafauna is the term used to describe the larger species of mammals, birds and reptiles that lived on earth during the Pleistocene Epoch.
Firstly is the fossil evidence of megafauna found in conjunction with human remains, particularly with evidence of hunting, such as embedded arrows and tool cut marks in the bones, and cave paintings depicting hunting.
It is theorised that the megafauna of Asia and Africa evolved with man, and learnt to be wary of them, whereas in other parts of the world the wildlife was ecologically naive and was easier to hunt.
en.wikipedia.org /wiki/Pleistocene_megafauna   (1122 words)

  
 [No title]
Mathematical models that incorporate the size and number of megafauna genera prior to extinction, the reproduction rate of large animals under the threat of extinction, and the population growth, and expansion rate of human predators, shows that the overkill hypothesis is feasible.
This paper is a bit antiquated at this point, and is based on the idea that “The only unique event during this period was the arrival of big game hunters.” Obviously this is a false premise given the mounting evidence of climate change and ecosystem alteration during this period.
Two main hypothesis have proposed mechanisms for this mass extinction event: the overkill hypothesis proposes that post-glacial human expansion was responsible for the death of millions of megafauna across northern latitudes.
www.uvm.edu /~pbierman/classes/gradsem/2001/megafauna.doc   (1798 words)

  
 News in Science - Sparks fly in megafauna debate - 31/05/2005
She believes megafauna may have died out at different times across Australia depending on a complex interaction of factors.
More evidence that points away from human intervention in the extinction of the megafauna comes from Queensland University of Technology research published today supporting the idea that climate change was responsible.
The researchers say this suggests the extinction of Darling Downs megafauna was caused by a massive shift in climate rather than by the arrival of humans who over-hunted animals or destroyed habitats by burning the landscape.
www.abc.net.au /science/news/stories/s1378661.htm   (752 words)

  
 Pleistocene Megafauna Extinctions on the Colorado Plateau
One camp in the debate contends that a rapidly changing climate at the end of the last ice age did in the Pleistocene megafauna, as they are called, by transforming their habitat.
In this view, the megafauna were betrayed not by the naivete of the big animals themselves but that of their immune systems.
But the changing climate, according to this hypothesis, changed the landscape as well; instead of widely scattered patches, habitat types like forest, savanna and prairie tended to be increasingly limited to certain parts of the continent.
www.cpluhna.nau.edu /Biota/megafauna_extinctions.htm   (2152 words)

  
 The Epoch Times | What Killed Australia’s Megafauna?
Africa is the only continent that has megafauna today; elsewhere they were extinct by the end of the Ice Age 12,000 years ago.
Other evidence suggests that most of the megafauna had already disappeared before the arrival of humans, with megafauna in Tasmania already extinct by the time humans arrived there 31,000 years ago.
The debate cannot be resolved until new techniques are applied to accurately place the last occurrences of megafauna and the arrival of humans in Australia, requiring further collaboration between the scientific disciplines.
www.theepochtimes.com /news/5-4-24/28063.html   (385 words)

  
 WORLDTWITCH - Carlos Yamashita, Anodorhynchus macaws as followers of extinct megafauna: an hypothesis
Após a extinção da megafauna neotropical, esses pontos arrasados de manada de megafauna são simulados ciclicamente em margens de grandes rios durante a estação seca.
After the extinction of the autochtonous megafauna these raised gaps are simulated along the river banks during dry season.
Although speculative, this work draws attention to the fact that the Neotropical fauna was, not long ago, still richer, and that complex interactions between the extinct species and the extant survivors existed, and these had an important role in shaping the behavior of many of the present-day species.
www.worldtwitch.com /cymacaws.html   (2881 words)

  
 Barlow: Megafauna extinction and phenotypic lag   (Site not responding. Last check: 2007-10-16)
Throughout that vast continental mass, a quarter of all genera of animals regarded as megafauna -- those weighing more than a 100 pounds, or 45 kilograms -- were lost to extinction.
In the Western Hemisphere, the Age of Great Mammals came to an abrupt end 13,000 years ago, when the mastodons and mammoths, the ground sloths and glyptodonts, the native horses and large camels, and a beaver and an armadillo both as big as a bear all disappeared forever.
North America lost 68 percent of its generic richness of Pleistocene megafauna (32 of 47 genera), and South America lost 80 percent (47 of 59 genera).
cogweb.ucla.edu /ep/Megafauna.html   (491 words)

  
 Megafauna Murder
The authors of the paper, titled "Megafauna Extinction: A Paleoeconomic Theory of Human Overkill in the Pleistocene," are the same trio of economists who wrote an earlier paper suggesting trade among Homo sapiens led to the extinction of Neandertals.
The authors of "Megafauna Extinction" posit that if early North American hunters focused merely on hunting relatively small animals such as rabbits and deer, accidental encounters with big megafauna like mammoths were common enough to result in megafaunal kills.
Once the megafauna are gone, hunters switch fully to chasing minifauna, which reproductively sustain their populations.
www.meta-religion.com /Archaeology/Other/megafauna_murder.htm   (1253 words)

  
 Megadig:what's it all about?
Megafauna were very large animals that once lived in Australia.
By studying their bones, the MAGNT team can tell how our megafauna lived, what Australia was like when they lived, and perhaps why they died out.
Megafauna is made up of the word mega which comes from a Greek word, megas, that means large, and fauna which comes from Latin and means animal life.
amol.org.au /discovernet/alcoota/about.asp   (315 words)

  
 SFL ORG. News Center Cold, not man, killed off Australia's megafauna, say scientists
In a paper soon to be published in Quaternary Science Reviews, Dr Field and Dr Stephen Wroe from UNSW argue that most of the giant animals died out in the Ice Age which occurred 130,000 years ago, long before the appearance of humans in Australia 45,000 years ago.
Their review of the available evidence indicates that only eight species of megafauna actually lived alongside humans.
"They are making a desperate attempt to try to dismiss the only site where megafauna and humans are found together, so that this dogma of the mass extinction 46,000 years ago can stand," she responded.
www.sflorg.com /sciencenews/scn062006_01.html   (455 words)

  
 Prehistoric Life - Ice Age Animals in Australia.   (Site not responding. Last check: 2007-10-16)
Evidence of the former existence of the Australian megafauna was known by the Aborigines, and was soon discovered by the earliest European settlers.
A large collection of fossils from Wellington Caves, west of Sydney, was sent to England by Major Thomas Mitchell in 1831 for examination by the renowned Sir Richard Owen.
Aboriginal hunting, or their use of fire which led to an increase in grasslands and dry forests may have been partly responsible, but it is likely that the drought conditions which occurred at the peak of the last glaciation about 18,000 years ago was also involved.
www.museum.vic.gov.au /prehistoric/mammals/australia.html   (419 words)

  
 Climate Change Caused Extinction of Australia's Giant Animals
Megafauna - giant mammals, birds and reptiles - roamed the globe in the Pleistocene epoch, between 1.8 million and 10,000 years ago.
Current theories suggest that between 50,000 and 20,000 years ago, increasing aridity in Australia led to cooler and drier conditions that decreased wooded habitats and expanded deserts and grasslands, but researchers have not clearly understood what impact it had on the giant animals.
The Darling Downs contain some of the most extensive and significant Pleistocene megafauna deposits in Australia but because it has been excavated since the 1840s it was assumed that the palaeoenvironment record was well established.
www.ens-newswire.com /ens/jun2005/2005-06-01-02.asp   (1033 words)

  
 Megafauna   (Site not responding. Last check: 2007-10-16)
:''See Megafauna (board game) for the board game'' Megafauna are the large animals of any particular region or time.
Generally a "large animal" is defined as one weighing over 100 pounds (45 kg), though the threshold may range from 10 pounds (5 kg) up to 1 ton (1 metric tonne).
The sense in which the term is used is usually apparent from the context: A particular group of large, extinct animals.
megafauna.iqnaut.net   (341 words)

  
 Australia's Megafauna
In this activity, you will investigate the animals that make up the Australian megafauna, how and why they are different to large animals found elsewhere in the world and what might have caused their extinction.
Your task is to answer a number of questions about the Australian megafauna by accessing web sites that have been identified as providing most of the necessary information.
On a map of Australia, indicate and name locations that are significant in the study of the Australian megafauna.
science.uniserve.edu.au /school/quests/mgfauna.html   (1246 words)

  
 Floral Legacies of the Megafauna
This open country would probably also have been the preferred location for hawthorns, crab apples, plums and locusts because all are intolerant of shade and today are more at home in forest edges and clearings than in deep woods.
The same may be said of fruit and seeds designed to be dispersed by the megafauna.
We can't bring back the thorn - molding megafauna, but we can and must bring back the assemblage of Wolves, Panthers, Wolverines and large raptorial birds that form the peak of the trophic pyramid and are needed to balance the system.
www.asecular.com /forests/megafauna.htm   (1324 words)

  
 NOVA | America's Stone Age Explorers | End of the Big Beasts | PBS
Known as the Younger Dryas, this partial return to ice-age conditions may have stressed the megafauna and their habitats sufficiently to cause widespread die-offs, Grayson and others believe.
"I don't think that evidence exists." Another question anti-overchillers have is how the megafauna survived numerous glaciations and deglaciations during the past two million years only to succumb to the one that closed the Pleistocene.
Grayson admits that overchill advocates have failed to develop the kind of records that are needed to test climate hypotheses in detail.
www.pbs.org /wgbh/nova/stoneage/megafauna.html   (1636 words)

  
 Planet Ark : FEATURE - Mystery surrounds the death of Australia's megafauna
If the dates are right, this questions earlier theories blaming the last ice age 21,000 years ago, or man hunting the animals to extinction after arriving about 60,000 years ago.
Smith says the new dates pointed to a third theory - the "slow burn" - in which the megafauna was gradually wiped out by man changing the landscape plus climate changes.
In Africa, these was the origins of the elephant, giraffe and hippopotamus - megafauna which thrived as humans and the animals evolved together.
www.planetark.org /dailynewsstory.cfm/newsid/12091/story.htm   (1144 words)

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