Guest essay by Eric Worrall
Just like the USA, Australian Megafauna disappeared from Australia soon after humans arrived, but scientists claim the evidence suggests climate change was responsible.
Giant kangaroo victim of climate change
Robyn Wuth
MAY 18 2020 – 12:11PMGiant kangaroos and enormous crocodiles that lived 40,000 years ago in tropical northern Australia died out because of climate change, a study has found.
As the rest of the world was running from giant man-eating carnivores, Australia was home to a kangaroo that stood 2.5 metres tall and weighed a massive 274kg.
It fought for its place in the food chain alongside a marsupial “lion” and the world’s largest wombats.
…
“The megafauna at South Walker Creek were uniquely tropical, dominated by huge reptilian carnivores and mega-herbivores that went extinct around 40,000 years ago, well after humans arrived on to mainland Australia,” said palaeontologist Scott Hocknull.
“Their extinction is coincident with major climatic and environmental deterioration both locally and regionally, including increased fire, reduction in grasslands and loss of fresh water.
“Together, these sustained changes were simply too much for the largest of Australia’s animals to cope with.”
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Read more: https://www.canberratimes.com.au/story/6760372/giant-kangaroo-victim-of-climate-change/
The abstract of the study;
Extinction of eastern Sahul megafauna coincides with sustained environmental deterioration
Scott A. Hocknull, Richard Lewis, Lee J. Arnold, Tim Pietsch, Renaud Joannes-Boyau, Gilbert J. Price, Patrick Moss, Rachel Wood, Anthony Dosseto, Julien Louys, Jon Olley & Rochelle A. Lawrence
Explanations for the Upper Pleistocene extinction of megafauna from Sahul (Australia and New Guinea) remain unresolved. Extinction hypotheses have advanced climate or human-driven scenarios, in spite of over three quarters of Sahul lacking reliable biogeographic or chronologic data. Here we present new megafauna from north-eastern Australia that suffered extinction sometime after 40,100 (±1700) years ago. Megafauna fossils preserved alongside leaves, seeds, pollen and insects, indicate a sclerophyllous forest with heathy understorey that was home to aquatic and terrestrial carnivorous reptiles and megaherbivores, including the world’s largest kangaroo. Megafauna species diversity is greater compared to southern sites of similar age, which is contrary to expectations if extinctions followed proposed migration routes for people across Sahul. Our results do not support rapid or synchronous human-mediated continental-wide extinction, or the proposed timing of peak extinction events. Instead, megafauna extinctions coincide with regionally staggered spatio-temporal deterioration in hydroclimate coupled with sustained environmental change.
Read more: https://www.nature.com/articles/s41467-020-15785-w
The issue of the possible role of Aboriginals in megafauna extinction is as sensitive in Australia as elsewhere. From the study;
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The ODP820 charcoal record illustrates an increased fire frequency starting ~44 ka, intensifies from ~40 ka, and peaking ~28 ka23,27,43(Fig. 3g). While anthropogenic landscape burning has been attributed to these increases over the last 50,000 years27,43, this has been challenged and a more likely explanation involves the complex relationship between climate and vegetation with fire frequency47. Importantly, the increased and sustained burning from ~44 ka indicates a fundamental shift toward environmental deterioration and instability that would have impacted the survival of megafauna.
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A role for people in the extinction of Sahul megafauna through their direct extirpation has been previously proposed. However, with no evidence of butchery or kill sites, it has been proposed that extinction occurred rapidly across Sahul shortly after human arrival12,13,14,22,52,53,54,55. In the absence of evidence for direct extirpation, indirect human-mediated factors such as landscape burning have been proposed but are difficult to differentiate from non-human factors15,16,21,56,57.
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Read more: Same link as above
I suspect humans at least contributed to Australian megafauna extinction, despite the delay between human arrival and extinction. The theory that humans had very little to do with megafauna extinction requires accepting the hypothesis that the abrupt extinction of megafauna which had likely survived for millions of years, and the arrival of humans at roughly the same time, was all just a big coincidence.
It is not necessary to believe that humans ate all the megafauna, for humans to have played a role in their extinction. A 2013 study suggested land clearance in Australia can cut local rainfall in half. Fire wielding humans can clear a lot of land, deliberately or otherwise, though as the study suggests, it would be difficult to differentiate human started fires from natural fires.
There’s a family of 5 kangaroos living up the street from me here in a country New South Wales town. I walk past them every day. If they were 2.5 metres tall I would take up running again.
My wife and I once encountered a family of Big Reds next to a toilet block at Little Beach. The kangaroos were hanging around waiting for scraps, looking menacing. The only reason we didn’t run is they can hop a lot faster than a person can run.
We get mobs of eastern greys around the property on a regular basis. My husband watched a couple of big bucks sparring up on a hill in silhouette of the sunrise.
The big bucks are quite muscular, if you happen apon them and they stand upright and stick out their chests it’s best to pretend you didn’t see them and walk quietly away.
Reminds me of the advice I got from an experienced guide on my first visit to East Africa.
“If you encounter an aggressive animal, stand your ground and try to scare it off, everything dangerous runs faster than you.”
However my experience is that there is actually only two really dangerous species in Africa, humans and malaria trypanosomes.
I have no direct experience, but I’d be inclined to add the Cape Buffalo to that list.
I have, and while it is a somewhat irascible animal it is safe provided you don’t go too close. African elephants are if anything more dangerous. One should also keep well away from Black rhinoceros while the White Rhinoceros is remarkably docile and peaceful.
I have read that the Hippospotamus claims more victims than any other African non human mammal.
They are incredibly strong and highly unpredictable, and just cuz you are in a boat don’t mean you are safe.
I do have some experience, and will second the motion to nominate the mosquito as the most dangerous animal in Africa, after humans. You can avoid danger from almost every thing else.
As a matter of fact hippopotami are more dangerous on land than in water. They defend their territories vigorously and attack all intruders includng humans.
Fortunately they only graze on land at night.
Never go outdoor at night when there are hippopotami around!
I think I’ll stay in Washington State, where the most dangerous thing you’ll encounter is a hipster in a Subaru doing 10 below the speed limit in the left lane.
“There’s a family of 5 kangaroos living up the street from me here”
How did 5 kangaroos get on the housing list?
Was it from a HOP fund or something?
Ba-dum tish.
Thank you, thank you, I’m here all week. Don’t forget to tip your waitress.
Like the Moa in New Zealand? Yeah right!
If you try to picture the immense habitat changes that would have accompanied the transitions from interglacial to glacial to interglacial stages, it’s easy to see how challenging those times may have been for megafauna… before humans became a significant part of the equation.
As I’ve often said, I think we were just the straw that broke the camelops’ back.
But 40 Ka was well before the Last Glacial Maximum. Maybe an interstadial, similar to previous milder glacial intervals in the last glaciación and the many such Ice sheet advances of the Pleistocene.
Please excuse my accidental Spanish.
What blew my mind was that 37 genera of large animals and some small ones went extinct over a period of several thousand years in North America – 60-something in South America. This talk by Donald Grayson is fascinating, and he discusses various hypotheses. Before this I had only heard about mammoths and humans. Climate is certainly on the cards. I wondered about the possibility of something like a prion disease that worked its way through the food chain, with smaller animals that reproduce faster ultimately able to overcome the disease.
I think there were multiple factors… But, people (and dogs) were just too much.
And the diseases on the fleas on the dogs…..
Whoops forgot to put in link
“liked” for the laugh of the day factor;-)
prior finds of suchlike critters from Sth Aus desert border areas worked on by flimflam flannery , who does a decent enough job on his own specilaty, found em trapped in caveins pits or areas they couldnt escape from
and thylacaleo the giant aussie lion relative was reckoned to have dropped in for a fedd and also got caught.
climate rated NOT a mention.
and seeing as the aborogines now try n push their arrival to 60k yrs back
we could blame them more than any other manmade effects maybe?
wombats cats n roos ALL do rather well in dry land/desert fringes right now
I doubt anythings changed.
crap like this really makes my hands itch to slap someone upside the head;-)
“the aborogines now try n push their arrival to 60k yrs back”
Which means that they would have arived in Australia at least 5,000 years before their ancestors left Africa.
Now there may have been humans in Australia 60,000 years ago, but if so they were Denisovans, not Homo sapiens. Aborigines (and papuans) do have a remarkably large admixture of denisovan genes.
Archaeology is such a free for all of spacious hypotheses and outright day-dreaming passed off as science, it’s not even worth pondering whether it’s right or not. Just assume it’s not and check back in 20-30 years to see whether they’ve changed the dogma.
The more I read the more depressed I get. We are witnessing the end of the age of enlightenment.
Given the marsupial prevalence in the area, the original hominids in Australia were obviously also marsupial. It is therefore thanks to the arrival of the Aboriginals that there are no more marsupial hominids. I for one am especially pleased by this as, like the Sea Horse, it was the Male Marsupial Hominid that contained the Pouch for carrying the young. The Vestigial pouch is still sometimes present in current males as the Kegger Belly
There was probably a lot of smuggling going on back then.
The megafauna in Austrlia was not eaten in the first two weeks after the aborigines arrived in Australia. They were on the menu for thousands of years until like many other Australian marsupials since, they eventually went extinct. The tradition was continued by White Settlersn with the Tasmanian Tiger in 1937. Fire wielding aboriginal hunters were able to clear a lot of land and hunt marsupials concurrently over the years, The loss of trees certainly altered the climate but was not alone able to eliminate the megafauna marsupials. The ill-fated Moa in New Zealand is another good example of invasion culling.
These days the Left finds the aboriginals’ success in food gathering, land clearing and advancing Natural Selection to be a great embarrassment and steers clear of it. ‘Climate Change’ is snow seen as a useful scapegoat.
There is no mention in the article above about when aborigines (or rather the first humans) came to Australia. Considerable dating puts the Lake Mungo find in western NSW in the range of 40,000 to 45,000 BC. I see on the net that the people there were a distinct race different to present aborigines. It is likely the later settlers (invaders) killed off these people as well as some of the fauna of which some were still around upto 10,000 BC (example the Tasmanian Tiger and Marsupial Lion). Evidence of aboriginal occupation has been found in NT and northern WA dating in the range 50,000 to 65,000 BP. There was plenty of time for the early inhabitants to change the landscape with fire and to kill some of the large slow moving fauna. The present aborigines have no connection with the first settlers in the country and maybe not even a second wave which was like the Tasmanian aborgines which became isolated when bass strait flooded around 12,500 BP. There are no full blood surviving Tasmanian aborigines.
nicholas
“These days the Left finds the aboriginals’ success in food gathering, land clearing and advancing Natural Selection to be a great embarrassment and steers clear of it. ‘Climate Change’ is snow seen as a useful scapegoat”.
My husband and I spent 7 weeks in Alice Springs, NT a couple of years ago. We didn’t see much in the way of roadkill let alone live kangaroos in the Territory. It’s easier to hunt with a 4 wheel drive and a rifle.
We get mobs of roos here in NSW, emus too.
We don’t know the lifespan nor number of offspring for these extinct megafauna. Early hominids didn’t necessarily need to be blood-thirsty hunter gatherers. God knows its easier and safer to catch a fish, rob eggs from a bird nest, or pick berries, than to organize a dozen people to go out and take down a large mammal with some pointy sticks. But if those creatures have few offspring, contributing to the death of one per decade might be enough to cause their extinction over a few thousand years.
So in the past humans were good and blame natural processes, now it’s humans are bad and natural processes are benign. Confirmation bias.
The aboriginal onslaught on the kangaroo did not have to be intentional. They did not have to try slaughtering the giant kangaroos. The use of fire stick burning eventually changed the trees and grasses from a decent pasture land suited to grazing by giant Kangaroos to either a near desert more suited to the smaller kangaroos (which did not need so much grass) or to eucalyptus forest, not suited to anything except koalas and small wombats.
Ironically kangaroos thrive on golf courses, where the fairways are well watered, and there are shady areas to each side, useful for resting at mid day. There they can watch the descendants of mad Englishmen going out in the heat of the day.
Somewhat of topic, but as you mentioned eucalyptus, I remember to have read, they are good absorber of NO2, that may be a reason to let them grow in towns and cities, despite the danger when it burns.
I just found a study about:
More than a 600-fold variation in nitrogen dioxide assimilationamong 217 plant taxa
Assimilation of nitrogen dioxide in response to fumigationwith 15N-labelled nitrogen dioxide was studied in 217 planttaxa. The taxa included 50 wild herbaceous plants collectedfrom roadsides (42 genera, 15 families), 60 cultivated herba-ceous plants (55 genera, 30 families) and 107 cultivatedwoody plants (74 genera, 45 families). Two parameters, the‘NO2-N content’, or NO2-derived reduced nitrogen contentin fumigated plant leaves (mg N g–1dry weight), and the‘NO2-utilization index’, or percentage of the NO2-derivedreduced nitrogen in the total reduced nitrogen, were deter-mined. The NO2-N content differed 657-fold between thehighest (Eucalyptus viminalis; 6·57) and lowest (Tillandsiaionanthaand T. caput-medusae; 0·01) values in the 217 taxa;62-fold in a family (Theaceae) and 26-fold in a species(Solidago altissima). Nine species had NO2-utilization indicesgreater than 10%, of which Magnolia kobus, Eucalyptus vim-inalis, Populus nigra,Nicotiana tabacumand Erechtiteshieracifoliahad NO2-N contents > 4·9. These plants can beconsidered ‘NO2-philic’ because in them NO2-nitrogen hasan important function(s). The Compositae and Myrtaceaehad high values for both parameters, whereas the monocotsand gymnosperms had low ones. These findings suggest thatthe metabolic pathway of NO2-nitrogen differs among plantspecies. The information presented here will be useful forcreating a novel vegetation technology to reduce the atmo-spheric concentration of nitrogen dioxide.
As verification for my earlier comment.
But climate change is only caused by human CO2 emissions?
“Together, these sustained changes were simply too much for the largest of Australia’s animals to cope with”
Yes sir, but isn’t that how it works? Nature’s species portfolio of life on earth at any given time is not a god given perfection of nature to be preserved but a fleeting glimpse of a work in progress in the cruel dynamics of evolution that has no place for our self appointed role as the manager of nature and the enforcer of the Bambi principle.
Or is the issue here that it was humans that had caused this extinction? If so why are humans not allowed to be part of nature and cause extinctions? Would this extinction have been more acceptable if it were some other species that had caused the extinction? Are we not part of nature? Are we from outer space?
https://tambonthongchai.com/2020/01/13/human-pollution-the-planet-is-doomed/
Some of us are from outer space.
Chaam – Your third paragraph is excellent! I have often tried to say the same. Somehow, many people seem to think we are an invader of this planet, not a product of it. DNA clearly shows we are related to the other denizens of this world. There is nothing foreign in our DNA.
Actually the ice ages had remarkably small effect on megafauna. There was a number of extinctions about 2.6 million years ago when the ice ages really got started, but the following 50 glaciations had remarkably small effect.
Until this last one, which was not very remarkable as ice ages go (at least MIS 12 and MIS 16 were worse), but this one was the first with Homo sapiens included, and that apparently made a lot of difference.
I would have liked one of those giant crocodiles for matching accessories for the entire family. Crocodile leather is very soft-pure luxury. What a hit the family could have made with matching crocodile accessories. For myself, I would like a crocodile hat (complete with teeth), waistcoat, jacket, belt, wallet, briefcase ,backpack, shoes and boots. Could even have them in assorted colours to coordinate easily-even a slob like myself could look stylish with little effort. The wife could have matching accessories, including handbags, purses and travel bags, although she wouldn’t be seen dead in a crocodile hat or waistcoat. All this from just one crocodile with lots of meat as a bonus. Alas, “climate change” has robbed us all of this. If it were not for us 20th century humans burning so much fossil fuel many thousands of years in the future, we could have had these luxuries, with kangaroo fur lining in the jackets, waistcoats and casual boots. Once again, just a single giant kangaroo would have made all of those luxury goods for the entire family with lots of high quality lean kangaroo meat as a bonus.
Damned climate change.
Mind you, if they were still around, COVID would have got them.
Sorry no extinct giant crocodiles in Australia. Palimnarchus and Quinkana were actually smaller than the saltie. Would giant goannas (Megalania) or giant snakes (Wonambi) do instead?
“the abrupt extinction of megafauna which had likely survived for millions of years, and the arrival of humans at roughly the same time, was all just a big coincidence.”
And note that this big coincidence happened at different times on each continent (and Madagascar and New Zealand), but strangely enough in each case just after humans arrived.
Also note that the megafauna became extinct in New Guinea at the same time as in Australia (they were part of the same landmass then). And it became extinct even in the parts of New Guinea that were rainforest then and are still rainforest, and have never burned.
This is just politically correct “noble savage” nonsense.
Bang on.Just to coincidental.Fire stick technology must have had a huge effect on the landscape.Sustained hunting of mega fauna over thousands of years and an altered landscape was most likely the culprit.
So, over large animals outstripped their food supply and succumbed to disease and predation from better adapted animals. Sounds just like climate, nature doing what nature does.
40 thousand years ago, say it isn’t so. Damn those CO2 spewing animals.
Prominent marsupial expert and keen catastrophic warmist, Prof Tim Flannery, wrote a tome called ‘The Future Eaters’ which laid the blame squarely at mankind.
I bought the book, read it, thought it bulldust, changed my mind after a while weighed down by weight of popular opinion, before going back to my original position (which is much the same journey I’ve taken with AGW).
Sure, early Australians preyed on the megafauna, but the changes in climate were profound as can be seen in the changes to the Australian flora through the ages (the latter being a subject I’ve long been interested in). Burning undoubtedly intensified those changes, but I rather suspect that was largely after the extinctions.
While the megafauna still existed, there would surely have been less need to burn as the megafauna would have done much the same job. It was likely that the loss of megafauna and the drying of the continent that went with that which would have increased the need to burn in order to create suitable habitat for hunting the remaining small to medium fauna.
I also rather suspect that the human presence here is older than currently agreed upon which, if true, would make the extinction through human predation theory even less plausible. Given the history of anthropology over the last half century or so, I doubt that this suspicion is any way a long shot. However, some of the best likely evidence of this may be under a good deal of seawater and, thus, not easy to find.
It is ironic, but proof that natural climate change killed off the Australian megafauna may be obscured by subsequent natural climate change.
I should add that I have no doubt that the New Zealand story is one of late human arrival to islands that caused significant extinctions, such as happened elsewhere in the second millennium AD.
That doesn’t correlate so easily to the Australian story, however. The timelines are vastly different and island fauna is far easier to destroy. If human predation played a part in Australia, it was likely as the megafauna was forced into smaller pockets of habitat due to climate change, in which case, the climate must bear greater responsibility. It is easy to blame ‘Stone Age’ humans if one thinks of them as fundamentally different to people today or, even more so, if one thinks of people today as a plague. I subscribe to neither position.
Clearing land with fire or whatever can have a significant impact on rainfall. On a fragile continent like Australia that could have tipped the balance.
Naturally occurring fires have the same effects. Climatic changes have many contributing causes. On a delicately balanced land mass such as AUS large herds of large herbivores well could have exacerbated vegetation loses from natural and human caused fire. Those herbivores could very well have initiated much of the problem by over grazing certain plants and leaving others which could have added to the fire fuel load. Lots of speculation in every direction, it was 40,000 odd years ago, hard to tell at this great remove from the actual events.
Yes, land-clearing can have a significant impact on rainfall. That is well-known.
However, large-scale (continental) land-clearing with fire by a stone technology would surely require an at least periodically dry climate and/or reasonably flammable vegetation to begin with. I’m not sure that sits well with the record.
The ‘fragile’ continent ethos is overblown, I believe. As a livestock farmer, I have little time for the idea, for example, that Australia’s soils are only suited to soft-padded marsupials. Australia is ‘fragile’ only because it is geologically old and geographically lacking the mountain ranges to ensure rainfall over much of the continent. Otherwise, it is more resilient than given credit for.
Australia-New Guinea is a large island, with unique megafauna, like NZ, Madagascar, Mauritius, Hawaii, etc.
Its big animals, unused to humans, had survived the same climate changes over the previous 2.6 million years.
Yes, Australia is an island continent, but the scales are vastly different.
The following is a general statement, not pertaining to your reply: People see what they want to see. The political left tend to see people as a plague and cast blame through prejudice. The right see stone age people as lesser people and, therefore, also cast blame through prejudice (no doubt, that shall offend many here deeply, but that doesn’t make it untrue).
I shall leave it there. Permanently. This site is important, for the carbon cult has to stop. But equally, the tendency to take righteousness too far should also stop. I have no doubt that I have upset many just a little on this site, despite being in agreement with them on the matter on which this site was founded, simply by calling myself any sort of leftist however moderate. It is the same attitude found on other similar sites, all of which I no longer comment on, that of always knowing better and it is both fundamentally a strength and a ritualised weakness in fighting the carbon cult, just as the early Australians had inherent strengths and weaknesses in their highly ritualised land-management
which they pursued to the detriment of greater scientific observation.
I’ll finish for good, with one observation gleaned recently from a similar site – the understandable ire of the right at the left’s antipathy to freedom of information should come with an acceptance that it was the left who saw fit to introduce it…, just as the Democrats should accept that it was the Republicans who stood against slavery. No side is always right.
Size doesn’t matter much, except perhaps for speed of man-made mass extinction.
Australia’s megafauna, like those of NZ, Madagascar, Mauritius and Hawaii were unique, truly insular. But humans also wiped out megafauna in Europe, Asia and the Americas, which consisted of similar species, with some American differences.
We know that modern people hunted mammoths, as opposed to just scavenging them, and that the tuskers had survived the Eemian and prior interglacials, no problem.
I hunt elk with a rifle. It is difficult to get just one let alone the last one. Hard to believe a smaller population of humans with spears and fire sticks wiped out a whole continent of only the larger animals. Same in the Americas and other areas like mammoths across Siberia. Huge area in a short period. This is an embarrassingly egoistic, impossible and stupid theory.
Maoris likely killed off the Moa. The alternative to the theory that humans contributed to the death of megafauna is all the extinctions when humans arrived in various places were a big coincidence.
Eric,
Granted the moa and carrier pigeons succumbed to human superiority but they are probably not the most wily or wary. Mammoths coexisted with man for 200,000 + years across Russia Asia then suddenly were gone. And they weren’t burned out. They went with several other megafauna some of which were probably not hunted hard like the saber tooth. Elk and Bison died by rifles. Pigeons by shotgun. They were all plentiful when living with spear hunters in north america for 20,000 + years. The cause could be simple but probably not. Man may have had some influence but probably not much. I’m thinking something like corona virus or sheltering in place
People with horses and firearms almost wiped out bison. Plus railroads. We did end the similarly numerous passenger pigeon. Big animals are easier.
Elk were wiped out in most of the PNW and had to be imported from the Rockies.
I had a dream just last night that I saw a group of passenger pigeons in a field. I wouldn’t mind if we tried to bring them back to existence.
Somehow, we apparently wiped out the Rocky Mountain locust, so some say. I don’t think we should bring them back. Perhaps the CCP will.
“we apparently wiped out the Rocky Mountain locust”
Color me shocked someone knows about that!
However, it’s claimed farming did them in. But they originated far from where plowing was going on, and the homesteads anywhere close were far and few between and very small.
Giving there’s no myths from Amerindians in the area mentioning massive locust swarms, before the 1876 farmers had that fun, it’s basically a very odd fluke of nature.
Actually nobody really knows where the Rocky Mountain Locust originated or lived between outbreaks.
By definition those animals that are still around are the ones that haven’t been exterminated. Naive animals that haven’t been in contact with humans are often exceedingly easy to kill.
Go to e. g. the Galapagos islands or South Georgia and have a look.
Or just compare how birds behave on Taiwan, where people don’t eat wild birds, and mainland China where they most definitely do.
The funny thing is that similar events occurred in North America shortly after the arrival of men.
Once is an accident.
Twice is a coincidence.
Thrice is enemy action.
Eric Worrall @ 7:23 am reminds me of the Maoris. That is it, three times. It is enemy action.
Sorry Mr. Hocknull. Thanks for playing the game. We are giving you a goodie bag with my autographed picture in it as a souvenir of your appearance here. Good Luck, and God Bless.
Not to mention Madagascar …. Four times.
Many other isolated oceanic islands as well. And North and South America should count as twice. Also Asia and Europe. The Eurasian-American megafauna survived the Eemian and prior interglacials. Then modern humans arrived.
While the change from glaciation to interglacial had to have stressful effects on megafauna around the globe, methinks the biggest culprit was “climate change” brought about by the CO2 spewing from the ever-growing number of cooking fires and intentional burns for clearing vegetation and driving prey to kill sites. But we shouldn’t blame the early humans; I’m sure someone will propose a theory of European Cro-Magnon people arriving in hide-covered boats and dugout canoes for hunting parties that led to massive die-offs. Some sort of Stone Age Euro-trash!
Just as well that Bunyips and Drop Bears survived hey?
It seems that there isn’t anything undesirable that alarmists haven’t blamed on climate change. I’m reminded of the joke about a man whose only tool is a hammer and for whom all problems look like a nail.
For me, the lack of balance or openness to alternatives, or positive results, is what I find so questionable about the entire blame game.
As in N. America, these mega fauna survived many similar climate shifts over the millions of years that they had existed.
It’s quite a coincidence that the one climate shift that coincided with the arrival of humans is the one that did them in.
So it’s proven, that human are also reponsible for the climate change, how ever…..
😀
I prefer the explanation that humans were the straw that broke the camels back. Megafauna animals were in moderate decline from the beginning of the Pleistocene as the Earth entered an ice age 2.58 mya and more desertification of the entire world with cooler temps became the norm for the majority of the time during glacial advances. Those colder and dustier times that became the new normal after the start of the Pleistocene were not the same environment that they evolved from over prior multiple millions of years when the Earth was much warmer prior to the Pleistocene. Some megafauna started going extinct 125,000 years ago, without any human cause.
Most of northern NA was covered in a vast ice sheet where life was effectively extinct under the ice that covered multiple millions of square miles including most of northern Europe. So except for interglacials every 40K to 100K years, the Earth was becoming a lot more of a brutish place to survive for the larger megafauna beasts, while smaller mammals began to thrive more. The extinction of megafauna was inevitable in the scheme of things without humans, but would have probably took another glacial advance of 100k years to wipe most of them out had not modern humans came along and finished the last of them off fairly quickly. There is no doubt humans played a huge role in this, especially at the end of the last glacial maximum, but they were already under stress for hundreds of thousands of years due to the vast ice age that has been with us the last 2.5 million years. Tasmania was even under glacial ice, so Australia was a much different place than it was today and that had to affect the megafauna there too over multiple ice advances and interglacials the last million+ years.
Hominoids of various kind were in full swing about the same time frame that the Pleistocene started, so why didn’t the later Neanderthals wipe out the megafauna in Europe over the hundreds of thousands of years they occupied southern and northern Europe and Asia during interglacials? They were fairly numerous and excellent hunters as well.
I just can’t see that the global megafauna were doing swimmingly well until us humans showed up, and then poof, we modern humans get all the blame. The megafauna had all been having a rough go of things for hundreds of thousands of years through numerous glacial advances that lasted tens of thousands of years between interglacials before humans showed up. Massive climate change has been the rule the last 2.5 million years throughout these glacial advances, and they were under major stress most of that time without human intervention, but we came along at just the time they were the most vulnerable, which was the end of the last glacial maximum when we finally finished the off. While the prehistoric overkill hypothesis is probably also correct in speeding this demise up, it was inevitable in the scheme of things for some of these megafauna to disappear just from intense climate demise with the ice age. Some are still with us, like the muskox, bison, horse, camel, and technically any mammals over 100 pounds but it has to be a combination of everything including harsh climate, not just humans responsible for everything. That sounds like the climate change debate that humans are now mostly responsible for global warming and climate change.
My take on this – and noting John Tillman’s allusion to it – is that climate and Man both had roles.
Man was a new intrusion onto the Sahul land mass.
Man had spears – maybe throwing spears, but certainly stabbing spears [think assegai].
And – crucially, I suggest – the fauna was naive.
They did not have the flight reflex that almost all animals do now, as soon as a human comes into sight!
So, the humans could go right up to these large animals, without spooking them; and assault them.
I first read this suggestion in Jared Diamond’s ‘Guns, Germs and Steel’ [IIRC], but it strikes me as reasonable still.
And if the climate was changing [there’s a surprise! It can do that!], fauna would have been stressed; add a human incursion, with big game hunter technology, and whoosh – megafauna is extinct very quickly, geologically.
Didn’t happen in Africa – the local fauna grew up with the evolving hominids.
But it did happen in North America [climate also fingered, I think], and in New Zealand – no real role for the climate, there.
Moas were good eating, naive, and flightless of course – so got eaten.
Auto
Erm, humans and their bipedal tool-using ancestors have been around for 3 million years at least. Indications are those people were actively hunting game a million years ago. So yeah, they would’ve had an impact even back then. Use of fire dates back about 300,000 years ago — that’s when dogs hooked up with us, mmm that smell of cooking meat. Each step increased man’s predation on the megafauna. Climate change, climate schmange.
Willy
It didn’t help when Man used fire to alter the ecosystems that the megafauna had evolved with, or to employ methods such as used by American aborigines, driving whole herds of bison over a Buffalo Jump and primarily taking the tongues and livers because they didn’t have refrigeration to preserve the meat. Those kinds of hunting methods were very wasteful and had an outsize impact on the prey populations.
So more historical data points to climate change not being caused by using fossil fuels.
Why are pathogens never discussed when trying to explain past mass extinctions?
Is it not possible that the arrival of humans brought new viruses and bacteria to which native fauna had no immunity? If modern day viruses can hop from animals to humans, why wouldn’t the reverse have been possible?
Someone correct me if I’m wrong, but the humans who migrated to Australia weren’t farmers. Hunters and gatherers, little different from the inhabitants who were there when the Europeans arrived. Land clearing is done by farmers, not by people who subsist on hunting and the edible fruits and roots they can gather. Burning land on purpose would be highly counterproductive. While I’m sure they had their accidental fires, I doubt they were deliberate.
Even falcons use fire to catch prey…..
Why not humans ?
Mark the Australian aboriginals were naked before white man arrived. Spinifex is a common grass in parts of Australia, and is difficult to walk through fully clothed without being injured. I was told by a full blood aboriginal that burning the spinifex flushed out small animals and made it easier for the hunter to get around. The fires were definitely deliberate, and I’m sure that at times they led to wildfires.
Aboriginal “fire stick farming” definitely was deliberate, and continues to this day in the Northern Territory. Read a great description of this in “The Greatest Estate on Earth” by Bill Gammage. Burning removes old dry grass and allows fresh grass to grow- kangaroos prefer short green grass. Burning also clears under brush making hunting and travel easier, and repeated burning removes smaller trees and creates grassland. Areas of scrub and timber were left to provide shelter. Early European settlers reported “parkland” and grassland in areas that are now covered in scrub and thick timber.
Mark Lee
It is well documented that Indians in California used burning routinely to open up the forests for access and provide more browse for the deer and elk they hunted. Some have suggested that the pure stands of coastal redwoods are the result of generations of burning because redwoods are highly resistant to ground fires.
I’m less familiar with Australia, but I recollect reading speculations that the very large lizards known to existed prior to the arrival of the aborigines were victims of burnings. Again, the burning was done both to gain access to land too densely vegetated to move through easily, and to incidentally kill animals that were then already cooked by the time they were found.
We still have large lizards in Australia Clyde, they’re called Perentie and are part of the Monitor lizard family. Here they are commonly called goanna and can grow up to 2.5 m (8ft 2in) long.
We have been told by indigenous people that they are good eating, though the white man isn’t allowed to hunt them.
Whoops forgot to put in link
Has Tim Flannery changed his mind on this subject I wonder? Before he became a climate activist he wrote “The Future Eaters”.
There is no doubt that increased fire and reduction in grassland were a direct consequence of the arrival of man in Australia. I don’t know about the loss of fresh water.
The Australian aborigines have a long history of regular small burn offs going back circa 50ky. It was the abandonment of this practice which has led to the recent periodic years of severe bush fires in Australia.
More like 40-45 ky. Have a look at this profile from Lynch’s Crater in Queensland. It’s not very hard to see that something drastic happened to fire frequency at that time:
Note that “MIS 6” in the diagram is the previous ice age. Nothing even remotely similar happened then. What was different this time around?
And by the way, notice that Poaceae = grasses increased strongly with increased fire, so no, it wasn’t “reduction in grassland” that killed Cock Robin.
The aboriginals still burn off in central and remote areas of Australia. Our early farmers were taught this method by the indigenous people and it worked well for them too till the leftist/greens put a stop to it. These days you can be fined for removing trees that are a danger to your home if you don’t go through the lengthy process of obtaining permission.
And I agree with you Eric, this has led to the more severe bushfires that we experience here in Australia today.
However the severe bushfires are mostly due to the dominance of eucalypts and other fire-prone vegetation.
This was not so in previous interglacials. See the diagram in the link above. Today’s Australian bush is a direct result of 40,000 years of firestick farming. It is really no more a natural vegetation than is Central Park.
Unfortunately there is probably no way to get back to natural much less fire-prone forests dominated by gymnosperms. There is no way to prevent eucalypts from burning long enough to allow other trees to take over.
“Unfortunately there is no way back”
Says it all really doesn’t it tty.
Retrospect, and all that. Trouble is, looking back, we were different people then. Who knew where our actions would lead us. Who knows where our actions will take us. Blame is futile when the future is changed forever.
Had another thought tty, we’ve sent eucalyptus trees right the way round the world. Trouble with humans, renewable energy as an example, we just don’t think things through. Cane toads were supposed to control beetles I think, they’re killing off our native species. Rabbits cause massive land degradation, feral horses, camels, goats and wild boar and deer were all introduced and compete for food with our other introduced animals, cattle and sheep. Not to mention dogs and cats. We can’t turn back the clock, and animal activists will insist we harm no creature.
Can’t burn off overgrown scrub to prevent bushfires, yet it’s fine to strip the forests for biomass.
I have no answers for the stupidity of mankind. In regard to mankind being responsible for the changing nature of the Australian landscape, I’m sure they largely contributed, but nothing is and has ever been static. Weather events, volcanic activity, colliding tectonic plates, tsunamis and asteroids have all made dramatic changes to the world past and present.
We think that we are so important, that we have the ability to control the climate. Yet in the scheme of things we have only been here for a nanosecond, we are a very small part of earths history, and likely it will continue long after we’re gone.
Everyone always forgets to take into account the one great law of biology:
“Under normal circumstances – when there is enough to eat – every group of animals expands in size until the group is to big, the food is not enough and famine breaks out.”
Animals eat themselves into famine through population growth – and so did humans until the 1960s, when population growth came to a halt in the Western World.
In prehistoric times that meant that humans had the choice between war with each other and hunting more dangerous prey.
There is not now and never was a balance in nature.
Humans never lived in harmony with nature.
Humans were hungry and over time found ways to kill and eat even the most dangerous animals.
Fun fact about Roos is they are one of the ultimate boom/bust drought survivors.
Roos have the ability to ‘stasis’ a pregnancy, so when a Mummy and a Daddy Roo love each other very much they can do the deed, and then the mother can wait until there is excess food around before giving birth.
Once born, the baby roo is about the size of a peanut and makes it way into the pouch and onto a nipple, where it remains until it is grown larger. While this is happening the mother is able to get pregnant again and also feed a larger joey. Hence three generations of roo are on the go at the same time and from this ability as long as there is water and grass, roos can breed like an Imperial College pandemic prediction.
Now back pre 1788 this worked out fine for roos. In droughts the population slimmed down to what the limited water and grass could support and once the rains came the population could explode again. And… die off again in the next drought.
Post 1788 those pesky Europeans started building dams as they spread their farms across the land. This meant for roos there was now a more reliable water supply, their population said ‘thank you very much’ and kept growing.
It has been argued that there are now significantly more roos in Australia then there were pre 1788 and that this is directly linked to European settlers changing the water dynamics.
So there you go. They may look cute and fluffy, but we also cull them for a reason.
(also if cooked correctly they taste great 😀 Australia, the country that openly eats it’s coat of arms. )
I’m with you Craig, kangaroo meat is yum! It’s also very lean and is high in iron, steaks are best cooked medium rare with a little salt and pepper, and the mince makes an excellent spaghetti bolognese.
Perhaps not so much dams as water bores tapping the Great Artesian aquifer. But it is almost certainly true that there is many more ´roos now than in 1788. In some areas e. g. in Pilbarra the density is almost absurd. I remember trying to drive from the coast to Tom Price one night. After an hour we gave up, stopped and put up our tents. It was impossible to drive faster than about 10 mph since ´roos kept jumping onto the road every few seconds.
On the other hand most small marsupials (and indigenous rodents) have been wiped out by foxes and cats.
tty
And introduced rodents?
And there’s many more white-tail deer, at least in the US now — hunting has been ostracized for the last few generations (just one of the reasons). Hello, chewed up landscaping, Lyme’s disease, and bloody carnage on the roads.
beng135
I spent my youth running around the forest in northern Illinois with my dog. Never once did I ever come across a deer, nor did I ever see tracks in mud or snow. Now the place is filthy with them, and I’ve seen white tail deer tracks larger than mule deer.
Two kinds of roos. One small and fast, the other big and slow. Who you gonna go after first?
Wow, we’re off the hook. I feel so much better….. (Humming the tune to Tie me kangaroo down, sport…..)
“Mega_fauna” — the so-called mega-roo was 8 feet tall, standing on its hind legs? That may be big for a kangaroo, but that doesn’t add up to mega-fauna to me.
Male American Grizzly Bears are about that size and weight — and we call them “big” but not mega-fauna.
Yes, I saw that article a few days ago. I was astounded to see those paleontologists claim “climate change” killed the large animals, just when people arrived. It’s not like it’s an unopened topic — this debate has been going on a long time and has been definitively won by those who acknowledge that the world-wide evidence that where people went they killed off the large animals, applies in Australia just the same.
I would like to add a contribution, though. There was a carnivore in those days, a particularly disgusting-looking type of hyena, which was undoubtedly a hostile threat. It disappeared at the start of human occupation, whereas other megafauna survived for another 20k years — this earlier die-out is considered a mystery. It’s pretty clear though, if you give it some thought, that wherever the aborigines went throughout Australia, the first order of business would have been to wipe out those hyenas. It probably explains a lot of the huge forest burnouts of the earliest time, as the people burned out forests just to get rid of the hyenas living in there. So no mystery why those hyenas died out first if you imagine yourself as one of those first people.
Another very annoying of those dumb-as paleontologists who cry “climate change” as wiping out large animals (which by the way had been surviving just fine for tens of millions of years) is that they’re purposely stirring up present-day unfounded fears about climate change. Clearly, scientists can be as dumb as anyone else — competence is a scarce commodity in every field, including science.
Willy
The whole issue of extinctions from dinosaurs to more recent megafauna is characterized by “What about ____?” No one hypothesis seems to adequately explain what became extinct and when. Perhaps that is because there were multiple reasons.
I concur with the view that early humans had little or nothing to do with the Australian extinctions. And even if humans had something to do with later extinction around 10,000 BP, the burden of proof, I must see first before I decide on this issue. I think that the extinction event must have been sudden, perhaps in the realm of being full scale catastrophe, something that the Giant Kangaroo was not able to avoid. Because of its very large size, the Giant Kangaroo was unable to hop, so avoidance of a cataclysmic event would have been next to impossible. I suggest, only speculating here is that some sort of cosmic event may have been responsible. We know only too well that comets and asteroids are capable of such an event. But, this long ago, there may well have been a not too distant star that went supernova. There are some tantalizing clues from various ice cores as in Antarctica particularly of sudden beryllium 10 increases, a possible sign of such an event. Thank-you Rod Chilton