In short, it hasn’t been very clear exactly what your position is, or else it has shifted. You started out by saying that human hunting was doubtful as a factor in causing the extinctions; now you concede that human intervention, at least, was a major factor, and may have been the primary factor.
Your main quibble at this point seems to be the relative effect of hunting vs other impacts caused by humans such as habitat change. However, among human impacts, hunting is by far the most plausible cause of the general extinction of megafauna. Anthropogenic changes to habitat, such as burning that converted forest to savanna, as a cause of extinction have exactly the same objection as climate, in that some species of the megafauna should have benefited from these changes and increased; instead, almost all became extinct, regardless of what their habitat preference was. Also, we see little early anthopogenc change to some habitats where megafauna became extinct, such as tropical forests. Likewise, we do not see decreases or extinctions in smaller species that might be expected to be affected by such habitat changes. I have already discussed why the disease hypothesis is unlikely.
But as has repeatedly been pointed out to you, to say that hunting was not the ultimate cause of such extinctions is purest nonsense. If a widespread species has been reduced to a very small localized population due to hunting or persecution, and that population finally receives the coup de grace from some other factor - whether volcanic eruption, grass fire, hurricane, or whatever - then the basic cause of that extinction was hunting, not that chance factor. To argue otherwise is absurd.
Also, can you explain why you eliminate subspecies/distinct populations in listing animals hunted to extinction? I was planning on adding the European Lion and the North African elephant.
Because, what dudes here are talking about is the “death of the pliestocene megafauna”, where many large mammal species died off, often around the time man appeared. In N. America that’s some 35 genera claimed to be the victims of clovis man. We can tell this ONLY by the fossil record, thus in comparing extinctions, we need also to compare animals from *recent periods * that would also be clear from the fossil record. Rare or “unsuccessful” species don’t leave much of a fossil record. Nor do subspecies (it can be very hard to tell a species from just a few scattered fossil remains). Then again, what consitutes a subspecies is more open to change and interpretation- look at the Quagga for example, which was though originally to be a dsitinct species but DNA has shown it to be “merely” a subspecies (at best). We have very little DNA evidence to go on with the Pleitocene fauna, certainly not enough to assign subspecies with any amount of certitude.
So, when we are comparing extinctions, we have to compare like to like. We can’t compare apples to “all fruit”. In fact, I was being easy when I asked for “large successful mammal species”, as I should have asked for "large sucessful mammal genera".
Even when we can point the finger at humans, hunting is not the only weapon in his arsenal. Martin used island extinctions are example, and uses New Zealand. No doubt, humans were a major force in the extinction of some 11 species of Moas:
“In no case is the precise cause or causes of these extinctions known. This is because in all known cases, human colonozation was associated with multiple possible impacts on the species that were lost. In New Zealand, for instance, people not only hunted moas, but they also set fires that quickly destroyed massive expanses of forest, and introduced competitors and predators in the form of rats and dogs. Some combination of hunting, introduced species (including pathogens) and anthropogenic vegetational changed caused the losses that are so well documented there. We cannot, however, say what that combination was. The same is true for all known prehistoric human-caused island extinctions. Becuase this is the case, none of these extinctions can be securely attributed to hunting alone, although this may have certainly occurred.” (italics mine)
If indeed, Human, or as Martin argues- Clovis man hunting, caused the megafaunal extinctions, you’d think there’d be more evidence. As of that article above (2002), there were exactly and only 14 (fourteen) sites that solidly show such evidence, and that evidence is confined to just two genera- mastadon, and mammoth. “… there are no demonstrable kill sites for camel or horse or for any of the remaining genera…”. In other words, looking purely at the record, Clovis man can be shown to have killed just a few mastodon and mammoth in North America. Oddly "After all, in other parts of the world- Late Pliestocene Europe, for example- are littered with sites that document human predation on large mammals. Martin claims that the killing in North America happened over such a short period of time that “we should not expect to find empirical evidence of that process”. “Martin argues quite differently for New Zealand, where he calls upon the abundance of archealogical sites containg moa remains to bolster his position that human hunting played a role in the extintion of these animals”. Seems sorta hypocritical to me. :dubious:
In other words, for North America, where some 35+/- genera/species were wiped out, representing millions of very large animals, there are exactly 14 kill sites during the “blitzkrieg” and those show only two genera. Odd, it seems that Clovis man also had a team of thousands of CSI experts cleaning up after them, too! :dubious:
Note also, that in order for Clovis man to be the killer of certain genera, that genus has to have been around when Clovis man arrived with his snazzy spears. *“However, of 35 genera involved, only 15 can be shown to have lasted beyond 12,000 years ago. This leaves open the possibility that many of the remaining genera became extinct well before Clovis times.” *
Finally “Martin has recently noted that archeaologists have always washed their hands of human complicty in large mammal extinction” in North America. He might also have noted that vertebrate paleontolgists who specialize in Late Pliestocene North America have also cleansed themselves of this noyion. The reason is straightforward. There is no evidence for it, and much against it. While Martin claims that a lack of evidence provides strong support for his position, others have different expectations of the empirical record… Given that archeaologists and palaontologists have washed their hands of North American overkill, who accepts it and what explains it’s popularity? As we have mentioned, scientists that praise overkill are, by far and large, scientists who are not familiar with the details of the North American Late Pliestocene." “It is easy to show that overkill’s continued popularity is closely related to the political uses to which it can be put.”
I don’t see why we can’t say that a species driven by hunting to such rarity that the last member dies of old age in a zoo was driven to extinction by hunting, even if the last member wasn’t actually killed and eaten by a human.
In that case, you likely could. But the American Bison, Mauritius Kestrel, Whooping Crane and (hopefully) the Ivory-billed Woodpecker will all claim they are not extinct.
As to the bird you are likely talking about, the passenger pigeon, there experts disagree on whether it was hunting that alone doomed the bird:
"Though it was a shameful deed, it was more than simply human hunting that doomed the Passenger Pigeon: it was our very presence. Its cousin, the Mourning Dove, is better adapted to living with humans and is so numerous that 30 million are killed each year with little threat to the remaining 400 million. The unfortunate truth is that had the Passenger Pigeon not been hunted to extinction, it probably could not have survived without the vast forests that supported its great colonies. Those forests no longer exist, and though they are growing back in some areas, they are much smaller and more fragmented. It seems that the Passenger Pigeons are no more compatible with modern man than were the forests that they called home. "
Habitat loss: clear-cutting of the forests is believed to be one of the
major causes for the extinction of the passenger pigeon (5). As forests were
cleared for agricultural use the system became fragmented thus making it
harder for the large colonies to nest together (5). As well many of the
pigeons favorite nesting sites, those containing mast bearing trees, were simply
eliminated (5, 7).
Technology: the railroad enabled large shipments of pigeons over long distances to city markets (7). The telegraph allowed rapid communication between pigeon hunters as to the location of the next nesting site (9).
Unsustainable hunting practices: as the demand for pigeon meat continued,
hunters exploited their nesting colonies. They often used poles or set fires to
the trees in order to get the juveniles as well as the adults (1, 9). Their
reproductive potential was inadequate to cope with the vast drain of its
numbers and the birds were not able to replace themselves (3, 9). "
And this sums it up, and helps with the OP too: http://links.jstor.org/sici?sici=0888-8892(198705)1%3A1<14%3ATESISA>2.0.CO%3B2-J We are well aware of the main mechanisms of extinction, especially those which derive from human activities. But these mechanisms tend to be studied in isolation from each other. We know much less and understand less still about the dynamic interplay between the discrete mechanisms. When we consider the likely outcome of several mechanisms operating at once, we can reasonably surmise that many of their effects will serve to amplify each other. These synergistic interactions are the subject of this exploratory paper. It is proposed that synergisms between discrete mechanisms, working collectively and with compounding impact on each other, will surely lead to a greater scale extinction episode ultimately. In the more immediate term, they may cause the episode to be telescoped in its time frame, especially in the early phases. This means that a large-scale elimination of species may occur even sooner than some observers anticipate. To the extent that this is so, there is all the greater premium on anticipatory planning and conservation measure, to be taken with due urgency."
But oddly, the bird does not seem to have been common before the white man:
"What can then be determined from this record – this paucity of bone remains – is that prior to European contact and subsequently, disruption of the environment, the passenger pigeon was a rare species. "
Back to the OP- here’s an article which places part of the blame MAYBE on our Dog buddies: http://links.jstor.org/sici?sici=0888-8892(198705)1%3A1<14%3ATESISA>2.0.CO%3B2-J
“Although archaeological evidence of the earliest American dogs is very scarce, they probably accompanied the Paleoindians who crossed Beringia and occupied North America after 13,500 cal. bp. By providing humans with hunting assistance and transport capability, as well as an emergency food source, dogs may have facilitated the very rapid expansion of Paleoindians. As hunters or as disease carriers, dogs may also have played a role in megafaunal extinction.”