But that doesn’t make the thesis false. Elephants in particular are fairly intelligent. They may have developed behaviors that saved them from extinction (and passed them on in a herd-like way) over the period of time that humans developed better weapons and hunting techniques. It’s a WAG, but seems like a reasonable one. The larger beasts on other continents would not have had the same amount of time to adjust their habits.
On another front, those folks quoted WAY upthread who have developed (one assumes computer) models of how many people it would take to hunt megafauna to extinction–where did they get their numbers? It seems unlikely that they have observed very many megafauna who are unaccustomed to humans. I’m not denigrating their work, just saying we might need several grains of salt here.
Don’t get me wrong-- I agree that it seems like a reasonable assumption. I’m just wondering what the data tell us. Is there any evidence that the African megafauna today is biologically different from the megafauna of 50k years ago. Maybe that’s too difficult a question to answer, but I’d like to hear from the experts.
It seems experts are divided if it was climate, disease or humans what caused the extinction of the mega fauna, the real answer is likely a combination of all those factors.
However, all those factors do IMO involve humans on the move (changing climate allowing and/or forcing humans to move, and humans also carrying diseases to other continents)
Even then, when a new convenient idea appeared, it was quickly adopted by all humans that got hold of it. I have the feeling humans developed new techniques on how to hunt big prey and not even (many) African animals were fast enough to adapt to the new human schemes.
Good points. I will point out that when humans were able to move, so were other critters- of course, sometimes along with the humans.
Your second cite contains a small error: *"The following disappeared from America, Europe and Australia:
All herbivores… > 1000 kg"*
Bison (including the Wisent) can & do weigh upwards of 1000kg- The biggest (American) specimens on record have weighed as much as 1140 kg, per Wiki.
Note from your second cite is also a quote about Martin "Detailed study of late Pleistocene extinctions in North America (Martin, 1986) suggests that they happened over just a few hundred years. This explains why there is so little archaeological evidence for hunting of mammoths in the New World. … Paul Martin has suggested that the human population quickly expanded south from the Bering land bridge, and exterminated the big game as they went (“Blitzkrieg” model). Martin, P. S.1986. ".
John, I equated Blitzkrieg with Aquatic Ape as they were both very interesting hypothesis, both based entirely on several interesting and amazing coincidences, and neither had any empirical data to back them up. Martin even admited his hypothesis couldn’t be falsifable, which measn it couldn’t be tested. Later, it turns out he was wrong, and there were tests and his original theory *was * false. From your link, it appears he later modified his original radical hypothesis. Still, he is unable to test his hypothesis.
The “mostly climate” side has some interesting facts and arguments too, from the second page of John’s cite:"*Guthrie (1984, 1995) suggests that the type of climatic change at the end of the Pleistocene was unparalled during the Quaternary and altered plant community mosaics resulting in a general trend of extinctions and dwarfing during the early Holocene. …
Vegetation communities during the Pleistocene are described by Guthrie (1984) as mosaics of high plant diversity that supported a high diversity of “climatically incompatible” animals forming “disharmonious mixtures”. Pleistocene age deposits show (now) northern species, such as grouse (Canachitas canadensis) and lemming (Synoptomys cooperi) existing with (now) southern species such as muskrat (Neofiber alleni) and skunk (Conepatus leuconotus) in Georgia (Guthrie, 1984). Guthrie (1984) argues that the diversity found during the Pleistocene was a result of the long growing season that led to a “sympatric tolerance” between plants that fostered diversity rather than homogeneity. This environment favored animals that were habitat generalists, that needed to supplement their diets with a variety of different plants to obtain necessary nutrition and avoid eating too many plants with strong anti-herbivory compounds.
The climate during the Pleistocene was colder and drier (Hoffecker, et. al., 1993; Guthrie, 1995), which favored the growth of grasses, forbes, and sages, which Guthrie describes as the "mammoth steppe". This grassy steppe environment was productive as an abundant source of nutrition for the herbivorous large-bodied mammoths, supported by the analysis of the Shandrin frozen mammoth's stomach content, found in Siberia in 1972 (Lister and Bahn, 1994). In his article, Guthrie attibutes the highly nutritious flora to the "plant-hostile" climate of this epoch, of colder winters with reduced snow cover and cooler, windier summers. This environment created an energetic stress on plants that led to their investment of energy into fiber-carbohydrate growth, rather than into anti-herbivory defenses.
Guthrie (1984) suggests that the Holocene interglacial led to a decline in mosaic vegetation and an increase in "zoned" or homogeneous vegetation communities, which resulted in a decreased quality and quantity of resources for mammals and thus a shorter growing season. These restrictions caused a lowering of the high faunal diversity, large body size, and large distributional ranges that characterized the Pleistocene. This type of environment during the last interglacial favored a mammals that are habitat specialists that eat a homogenous, monocultural diet (Guthrie, 1984).
Thus, the large bodied mammals that dominated the Pleistocene, were subject to a decrease in quantity and quality in food supply, and increasing seasonality at the end of the Pleistocene, that led to the extinction of some mammals and created a biotically different Holocene environment. "*
There is a huge debate going on over whether it was mostly human (deterministic) or mostly climatic (stochastic). Since humans arrived, there has been a considerable increase in extinctions, but nearly all have both factors. For example, take the Great Auk (the original * Pen-guin). There is no doubt that the last few Great Auks were killed by dudes working for collectors/“naturalists” and museums in 1844, on the island of Eldey, near Iceland. *(deterministic) * The last few were hunted down as they had become very rare. But what made them so rare? Well, they were hunted by man since at least 2000BC, so that’s deterministic. But generally, when a certain prey gets hard to find, food hunters *usually * stop going after it, picking on something easier (if you are hunting to survive, you go after the easiest calories). Which more or less happened, as the Great Auk had been resticted to a hard to get to island off Iceland, and the hunting was more or less down to a few birds being collected for “naturalists” :rolleyes: . Then comes the stochastic factor- in 1830, the island of Geirfuglasker (the Auk’s home) blew up and sunk, taking just about the last auks with it. This led to their great rarity, which led to the last few being hunted down. Mostly deterministic, sure, but the last home and breeding ground being sunk suddenly by volcanic action is certainly a critical stochastic factor.
Anyway, I am not taking sides in the “great debate”. But, I can say that Martin’s original radical hypothesis has been proven wrong. Almost no expert now says it is entirely one or the other. So simplistic answers like*:“Clovis man, with the Spear, in a century”* are part of the past, with Piltdown Man.
you can win a bar bet with this factiod, it is generally conceded that the word “penguin” was originally a name for the Auk or Geirfugl.
I was trying (not too successfully, it seems) to make the point that it might not be biological change at all. Many of the African megafauna didn’t make it–maybe they were the ones without the intelligence and/or ability to pass learning along (herd behavior). Mama elephant sees curious baby elephant move towards the funny upright apes. Baby elephant gets smacked and learns to watch out for said apes. Mama does that because HER mama did it. Giant sloths didn’t have the same capability, perhaps.
Note that I’m speaking ex-cathedra from my bellybutton here. I have no background in this stuff. I’m a software geek.
Quite simply untrue. Up until the start of the Iron Age Asia had more large species than Africa.. In fact IIRC Asia had more large species than Africa up until the 16th century.
Simply untrue. The three endemic American bison species became extinct around 10, 00o years ago; surely that qualifies as “putting a dent in the population”? The sole remaining bison species in the Americas is the newly arrived Eurasian bison, a species that co-evolved with modern humans.
Can we please have a reference that mastodons and giant sloths are harder to kill?
I’ll just repeat what I said in an earlier thread: I fail to see any practical distinction between “humans precipitated the extinctions with the timing and extent dictated by climate” and “humans caused the extinction”. I’ve really never understood those who try to adopt such a position as though somehow mitigating the role of humans.
Large AND successful? What you are asking for is a list of large species that proved they could successfully deal with human predators but somehow couldn’t cope with firearms. I have to question exactly what such a list is supposed to tell us.
Yes, and an article that has been thoroughly debunked by Flannery, amongst others. Quite simply the article relies on three highly flawed assumption.
The first is that humans only prey on either small or large species but never the both together. In fact what we find is that humans prey on large species, and when they become scarce they turn to small game. That allows human populations densities to remain high and never allows large game species to recover. Thus the conclusion that “smaller megafauna would have been more readily exterminated than larger megafauna because they would have been harvested at a higher rate to satisfy the demand for meat” is fatally flawed, a sis the extended argument that regula fauna would have suffered before megafuna.
The second flaw is the contention that “hunting efficiencies required to drive medium (500 kg) and larger (1000 kg) sized megafauna to extinction appear unrealistically high”. When humans interact with naïve animal populations hunting efficiencies are indeed unrealistically high. Naïve animals simply allow humans to walk up and club them on the head.
The third flaw is that the megafauna existed in eucalypt savannas, whereas Bowman’s own research has shown that the current Eucalypt savannas of Northern Australia are almost entirely anthropogenic. Bowman has taken a lot of flak for overlooking something that he his own prior research did so much to establish.
No, it does not. What those tow articles show is that there are certain assumptions required which are debatable. Nonetheless the majority of scientists accept the overkill hypothesis. Even Bowman himself accepts the overkill hypothesis to a limited extent, albeit combined with fire mediated vegetation change.
Can you please explain what climate change allowed humans to spread to Australia, New Zealand, Madagascar and New Caledonia to name but a few points?
Sigh. I debunked this nonsense when you brought it up in previous thread. Instead of conceding the point there you trot it out again now. There were no exotic rats in Australia when the megafauna vanished. There were no exotic animals at all except humans.
Can you provide any evidence at all that a disease has ever lead to the extinction of a megafaunal species?
You seem to be labouring under the misapprehension that overkill and blitkreieg are synonyms. They are not.
Neither blitzkrieg nor overkill are wrong according to your sources. According to your sources they require assumptions which not everyone agrees with. If you wish to debate those assumptions then I will happily enlighten you over in GD.
Yes, you state din an earlier thread that there were no endomic Rattus species in Australia. When I debunked that claim and pointed out there were dozens you refused to even reply. Yet here you are repeating the same basic claim.
Nonsense. Overkill is supported by such luminaries as Jared Diamond, Mike Archer and Tim Flannery amongst others. Far from having few backers it is accepted by the majority of biologists and palaeontolgists.
Blitzkreig can still boast the support of Flannery and Diamond amongst many others.
As far as facts, they fall very heavily in the Overkill camp. The disputants rely rather upon models.
No, Colibri and I agree on this one: humans were responsible. Animal populations were decimated or forced into refugia due to human activity and as a result were unable to weather environmental change. Had humans not intervened the species would have ridden out the climate change just as they had numerous times in the past.
Your position is akin to claiming that humans didn’t exterminate the dusky seaside sparrow. That species was killed by a grassfire. The fact that human shad reduced the population to 3 breeding females was irrelevant because a grassfire finally did for them and grassfires were natural in their environment.
This is clearly nonsense. The fire was natural but the species condition was anthropogenic and it was the anthropogenic factors that left them vulnerable. So it was for climate change induced extinction: the coup de grace may have been natural but extinction was entirely attributable to humans.
Simply untrue. There is a large amount of empirical data to back up the blitzkrieg hypothesis. Datings of human arrivals, weights and habitats of extinct species, survival on islands or other human isolated refugia. These are all empirical evidence of blitzkrieg.
The only way you could possibly say that there is no empirical evidence if you wish to argue that no past event can be said to be supported by empirical evidence.
Highly unlikley
Almost every species over 30kg was exterminated in Australia, yet koalas and wombats survived. These are species that are noted for being as dumb as fungus. Similarly in North America the intelligent elephants and horses were exterminated while the bison survived. In South America the giant ‘gorilla’ monkeys were exterminated while the less intelligent camelids and rattites survived.
There isn’t any correlation between survival and intelligence, learning ability or even maternal care.
More likely these species simply had no genetic defence against humans and had no ability to evolve such a defence. Large slow breeding species such as elephants and giant monkeys never got operated on by the processes that selected for more skittish individuals in other species.
Well, sorry Blake, I am leaving on vacation. Next time,come in earlier,willya? Err, dude “There were no exotic rats in Australia when the megafauna vanished. There were no exotic animals at all except humans.”- you do know about the dingo? You also know that Australia is just one single continent right? The fact that Rattus has driven scads of species into extinction doesn’t means it has done so every where. We are talking about the whole world, not just one area.
Did ya even read my cites? Can you dispute them? Do you have any cites of your own or just your own opinion? :rolleyes:
Anyway, thanks Scissorjack for a great OP, thanks John Mace for the debate, thanks everyone for your contributions,and have fun n your vacation, Colibri.
I’ll be back sometimes between Tuesday and Thursday. Enjoy!
Oh, I’m liking this one: I know when I’m out of my depth, but this one is an education in itself, and many thanks to all who’ve contributed. Blake, I was hoping you’d show up - I always learn from what you have to contribute.
Well I notice we are both back now so we can contnue.
Sigh. The dingo arrived in Australia no more recently than 5, 000 YBP. The last of the megafauna vanished no later than 25, 000 YBP. I repeat: your claims that there were any exotic animals in Australia when the megafauna vanished is pure bunkum. I have debunked it comprehensivley for you in previous threads which I will link to if you wish. Your claim has no basis in fact.
Precisely. And this sort of selective application is what makes attribution of the extinctions to non-anthropogenic or indirect anthropogenic causes so weak and such shoddy science.
According to your position it is exotic animals, except in cases such as Australia where there were no exotics, and then it has to be disease, except in cases such as North Am where disease is implausible, and then it has to be fire, except in cases such as NZ where fire wasn’t used in most regions and so on and so forth on an ad hoc, case-by-case basis for every major landmass.
This approach requires a selctive application of the facts to fit your theory. It makes for a weak argument and incredibly shoddy science. In contrast attributing the extinctions to direct, deliberate anthropogenic forces requires only a single assumption to be made that can be applied and tested universally.
Umm, dude, I just provided several hundred words critiquing your “cites”. Not sure how you missed that.
“Cites” for what exactly? As you would well know form past experience you only need to ask and I provide any refernces you like, but you will need to ask for something specific.
That’s merely an application of mathematical predator-prey models to the Australian case. As such, it is heavily dependent on its basic assumptions, and it can hardly be considered to be any kind of definitive “proof” that humans were not responsible for the extinction. In any case, Blake has already addressed reasons why the assumptions may be wrong and the analysis incorrect.
Again, this is a modelling excercise. In this case, it is used to question other analyses that purport to show that the overkill hypothesis is correct. They conclude their abstract:
Note that all they are claiming is that the “blitzkrieg” model is not proved; this is quite far from establishing that it is incorrect. Once again, IMO mathematical models, while they can be instructive, cannot be considered to be definitive proof on either side of the question, because it is impossible to be sure about the reliability of the underlying assumptions.
As I said before, I consider this to be an excellent summary of the evidence to date. However, you continue to misinterpret it as somehow supporting your position. I am not sure if you have actually read it yourself, or only seen the abstract and the bits I have quoted previously. It generally affirms, as I have said, that human impacts were almost certainly the most important factor in some regions, exclusive of climate; and in other areas human impacts interacted with climate to produce more severe megafaunal extinctions than would have otherwise taken place. In only very limited regions or cases, if any, does the article suggest that climate may have been the most critical factor.
From the article, which unfortunately is not available on line:
Note that rejection of “blitzkrieg sensu strictu” does not mean rejection of the conclusion that humans instead of climate caused the extinctions. The blitzkrieg hypothesis is a narrow and extreme one, postulating that the extinctions occurred almost simultaneously with the arrival of modern humans. Instead, extinctions could have been more drawn out - the “sitzkrieg hypothesis” as described well by John Mace and due both to hunting and other human impacts.
It doesn’t say that horses, mammoths, and Irish deer would have survived, merely that they would have survived longer in the absence of climate change - but humans were still ultimately responsible for their demise. As I have said before, I agree with Blake that there is little difference in saying that “humans precipitated the extinction” and “humans caused the extinction.”
In other words, the arrival of humans and not climate was probably the most important factor in Australia (even if blitzkrieg sensu strictu is incorrect), but details remain to be worked out.
For South America and Africa data are less clear; however, human effects, particularly in South America, could certainly have been important.
So it would seem that Barnosky et al. support the Clovis/blitzkrieg hypothesis. I personally don’t think it is correct, but I will expand on this in another post.
As I have said, I personally agree that Martin’s Clovis-blitzkrieg hypothesis is not correct. However, it is wrong to contend, as DrDeth does, that just because this one extreme scenario is wrong, that humans were not responsible for megafaunal extinctions. DrDeth seems to confuse the specific blitzkrieg hypothesis of Martin with the more general proposition that humans were responsible for the extinctions. However, I do not think that that particular article is very good; it is mostly just an anti-Martin diatribe.
Glad to hear it.
“Wrong” is not the correct word to use with regard to the first two citations; they merely do not prove anything definitively one way or the other. The second two citations I agree with. However, the first, according to my reading, indicates that human impacts were in general more significant than climate change; while the second contradicts only one narrow hypothesis, not the more general impact of humans.
We’ve had this discussion before, and you continually narrow and redefine your terms in order to have fewer species it can apply to. The last time you brought it up, it concerned any “widespread, successful species,” not just mammalian. When I brought up Passenger Pigeons and Great Auk, you claimed that habitat destruction being partly involved in the case of the former, and a volcanic eruption in the case of the latter, somehow negated the fact that overhunting was overwhelmingly the major factor in the demise of these widespread, extremely successful species.
Now you want to limit the case to mammals, and only look at cases where humans have caused complete extinction of an entire species; ignoring the fact that humans have unequivocally caused extinctions over large parts of species’ ranges, that survival of some formerly widespread species, such as the bison, has been entirely due to human intervention; and that other species that became extinct, such as Steller’s Sea Cow, were not “widespread and successful” in recent times only because of former human hunting.
Steller’s Sea Cow originally had a very wide distribution around the North Pacific rim and was highly successful. The reason for its extinction on mainland coasts was certainly aboriginal hunting; it clearly can’t be attributed to climate change because some survived in the Commander Islands until the 1700s. Since a population had evidently persisted in these uninhabited islands for many thousands of years, there is no reason to suppose they would have become extinct there without human hunting.
On re-reading this thread, I withdraw this remark. DrDeth does understand the difference. But he keeps bringing up evidence against the Martin blitzkrieg hypothesis as if this also refuted the significance of human impacts in general.
I’m not certain he does appreciate the difference. This is because he continually uses phrases such as
That seems to clearly imply that he sess Overkill and Blitzkrieg as synonymous. I would appreciate it at this stage if Dr. Deth would clarify that he does appreiate the distinction and doe sunderstand that even if one is wrong the other need not be.
This time it isn’t just mammalian, it is large and mammalian, and successful and began to decline since 1500. As I noted earlier, I have trouble seeing what such a list could possibly tell us. It would at best be a list of species that could cope perfectly well with modern human hunting but for some reason succumbed to firearms and not to the plethora of other weapons in the human arsenal. What exactly could that tell us WRT the topic at hand?
I gave a pretty thorough critique of the Clovis evidence in this post in the thread that John Mace linked to in post 7 of this thread.
To sum up, in the original Martin blitzkrieg hypothesis, he postulated that the Clovis big-game hunting culture colonized North America from Asia, entering as soon as the ice sheets had melted enough to allow a passage east of the Rockies through the Canadian Great Plains, and that Clovis represented the first humans in the Americas. Martin proposed that these big-game hunters, with superabundant prey, built up a high but transient population density along the colonization front. This high-density population is what caused the rapid extinctions; most local extinctions, according to Martin, may have taken place within a few decades or at most centuries. As the colonization front spread through the Americas, the megafauna became extinct in its wake.
However, there is little (or no) evidence for this specific scenario. Some of the evidence against it:
There is now strong evidence that humans were in the Americas well before Clovis, by at least several thousand years, although evidently at quite low densities.
There is no clear evidence that Clovis came from Asia.
Although Clovis spread rapidly through North and Central America, there is no clear evidence that the spread was from north to south.
There were also post-Pleistocene big-game hunting cultures in South America, and Martin and others have postulated that these descended from Clovis. However, there is no good evidence that this is so, and these cultures are more likely to have been of independent origin from populations already present in South America. There evidently was a convergent development of big-game hunting cultures, which used similar but not exactly equivalent tool kits, at the end of the Pleistocene in both continents.
While I do not think that the specific Clovis-blitzkrieg scenario is true, I do think that humans were mostly responsible for the megafaunal extinctions in the Americas. This may have been due to either attrition over several thousand years - sitzkrieg - or may have been due to the origin and spread of big-game hunting cultures in both North and South America post-Pleistocene - a modified, non-directional, blitzkrieg.
I note that Grayson and Meltzer, cited by DrDeth above, argue against Martin by saying that 1) humans were present in North America before Clovis; and 2) some of the megafaunal extinctions were pre-Clovis. This is exactly what one would expect if sitzkrieg were responsible for these extinctions. However, I have not reviewed the evidence closely enough to know whether the extinctions were really spread out over time, or as clustered as Martin claims. Barnosky et al evidently do accept that the extinctions were clustered, and Clovis was responsible for most of them.
Although the megafaunal extinctions in the Americas may have coincided with both the spread of big-game hunting cultures, and with a period of rapid climate change, I would argue the first was paramount because the extinctions affected all climatic zones and all habitats, even those that were expanding. Proboscidians became extinct from the tundra to the eastern forests to southwestern semi-arid areas to the tropical forests of Central and South America. Likewise all ground sloths became extinct, whether they lived in deciduous forest, sagebrush desert, savannas, or tropical forests. Likewise for the other groups of the megafauna. It’s hard to postulate a climatic change that would have done all of them in simultaneously, especially when most of the smaller species survived quite well.
As has already been stated, humans spread into most areas long before major climate change occurred, in particular Australia. In orher regions, climate change may have had an effect on the extent and timing of human impacts, but the presence of humans was crucial (in most areas).
As **Blake ** has already stated, rats had exactly zero to do with megafaunal extinctions anywhere, whether on continents or islands. Human-introduced rats have had major impacts on smaller fauna on islands, but probably had little effect on larger species such as moas in New Zealand, and certainly had zero effect on giant lemur or elephant extinctions in Madagascar. I don’t recall that anyone has ever proposed that rats had anything to do with the extinction of mammoths or giant ground sloths.
What other species did you have in mind whose spread would have caused megafaunal extinctions?
Of all the hypotheses advanced to explain the megafaunal extinctions, I think disease is by far the weakest one, as a general explanation on a global scale. Certainly disease has had an impact in isolated areas in historical times, but only within restricted groups (e.g. avian malaria in the Hawaiian Islands, but this has affected mainly one order, the passerines).
Only Australia was isolated enough that it might be imagined that novel diseases from the outside would have had much of an impact. However, the extinctions affected not only mammals there but also large reptiles and birds. The mammals were marsupials of a wide variety of orders. It is extremely unlikely that humans, which were the only species to colonize Australia prior to the megafaunal extinctions, could have transported pathogens that would have affected all these groups.
For Eurasia and the Americas the hypothesis doesn’t hold water either. Extensive interchange of faunas took place through Beringia during previous interglacials without provoking extensive extinctions. Again, the extinctions affected a wide variety of unrelated groups, from proboscidians to ungulates to carnivores to edentates to large rodents. It is impossible to imagine that one or a few diseases transferred through faunal interchange could have been responsible for extinctions across such a wide range of taxa. In any case, this hypothesis, like so many others, does not explain which smaller animals were much less affected by extinctions.
I do not and did not claim that humans were not a cause. In fact,they might well have been the Primary cause. What I claim is that human hunting was not the* only *cause as **robby **seem to claim in post #3, and as the *original *Martin Hypothesis claimed.
Climate played a more or less important role,and humans had plenty of ways to induce extinction other than by just hunting.
Blake used Jared Diamond is his “appeal to authority” but Diamond in “Guns Germs & Steel” carefully considered both sides-
“overkill” and climate. His conclusion was “Hence it seems to me most likely that the giants were indeed exterminated by humans, both directly (by being killed for food) and indirectly (as the result of fires and habitat modifications caused by humans). But regardless of whether the “overkill” or climate hypothesis proves correct…”
I would have thought so myself, except I had been reading David Quammen’s “The Song of the Dodo” (an excellent book). Pg 542 of my edition, contains the following " Mark Shaffer’s contribution to the Blue Book was titled “Minimum Viable Populations: Coping with Uncertainty”…Although systematic pressures inflicted by wilful human activity can drive a species down to the margin of viability, Shaffer wrote, the terminal event- extinction- will generally involve an element of chance." (By “chance” he is talking about Stochastic factors here,not Deterministic factors. ) pp 516 “In general, there are four sources of uncertainty that a population may be subject”, Shaffer wrote. He listed them: demographic stochasticity, environmental stochasticity, natural catastrophes, genetic stochasticity."
In other words, human hunting generally drives a species to near-extinction “margin of viability”, and stochastic factors finish them off. Sure recently, as in the case of the Mauritius Kestrel,humans can re-intervene and save the species.
are part of the past, with Piltdown Man.