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Recent extinctions

The mammoth extinction discussion got me to look at the B. bison thing. 

It may have been that the array of super bears, cats and wolves on the 
plains used to keep bison numbers in check until those carnivores went extinct. 
Then the new predators, the early plains indians, may have done the same. As 
you recall, the introduction of Eurodiseases into the Americas devastated 
the aboriginal populations. The absence of any predation among the 
r-strategist bison may have led to their population quickly ballooning to the 
tens of 
millions. But by the late 1700s early 1800s plains Indian numbers were 
rebounding, and they got horses and then firearms. They may have been 
bison numbers by the mid 1800s. Now, when I was a kid we learned about how 
the obtuse early frontiersmen called the western plains "The Great American 
Desert" -- how silly of them we were taught. Actually, it was a desert at 
the time because of a mid 1800s superdrought that probably drastically reduced 
the bison pop. Then rains leading up to the early 1860s brought back their 
numbers somewhat. 

Westward migration from the east slowed when the southern traitors who 
wished to keep folks in terror based bondage revolted against these United 
States. After the war many of those disaffected traitors headed into the 
southwest, as portrayed in the best western/Wayne film of all, The Searchers 
costarred the future Captain Pike of the USS Enterprise. This is why the SW 
was as virulently Jim Crow as the SE well into the 1900s. Also, the US 
government paid the rail companies to lay down the transcon railroad. So 
migration to the west resumed across the northern and southern plains, as did 
the cattle industry on the open range, leading to the cowboy culture that 
consisted of minimum wage workers hitting the new towns to drink, gamble and 
hit the brothels. Also having a good time in town were the buffalo hunters. 

In twenty years commercial hunting reduced the bison to a few hundred. It 
was almost entirely for the skins. The Feds were all for this. To eliminate 
competition for the cattle ranchers. To keep the damn buffalo off the 
railroad tracks (especially in the winter when bison herds used the cleared 
to move along, holding up trains for days -- it was very annoying). And to 
drive as our beloved Declaration of Independence calls the merciless Indian 
savages (it's always a cringe factor when they get to that part of the NPR 
recitation every 4th) to the reservations. Buffalo Bill got concerned. But 
prez Grant refused to sign a bision protection bill. By the mid 1880s the bison 
would have been extinct if a few had not been kept for old times sake (I 
think most at Yellowstone Park). That was as the open range was just beginning 
to be fenced up by them dang homesteaders, so habitat destruction had 
little to do with it. 

That the bison were so quickly eliminated from a large part of a continent 
negates the cited argument concerning the difficulty of killing off Cape 
buffalo. It is not a great analogy for Paleoindians hunting the megafauna to 
extinction. Also irrelevant in the difficulty of wiping out roos. They are 
modest sized r-strategist weed taxa.  

Someone brought up the passenger pigeon. There is an argument that their 
populations were not as colossal pre 1492 as they were in later colonial 
times. PP were big mast eaters - acorns, chestnuts, etc. So were Indians who 
developed a protoagriculture based on mast trees across the continent. Used 
to suppress nonmast trees, the latter dominated the Yosemite Valley floor 
when the whites arrived for instance. PPs populations remained modest. A line 
of evidence for this is that even though PPs make good eating, their bones 
are rare in Amerindian middens which would be all the more odd if they were 
superabundant and as easy to kill as they were in the 1800s, and the Indians 
sure knew how to kill and eat critters. Then the Eurodiseaes wiped out most 
natives and the mast forests went wild, and the theory is that the 
delighted PPs had all the nuts they could eat and their populations soared to 
rmal levels. So when the Brits showed up in the 1600s is looked like a near 
human empty wilderness of oaks, chestnuts with abnormally huge PP flocks 
flying about. Continued disease pressures kept Amerindian populations west of 
Appalachians low until the early 1800s, keeping the PPs happy as doves. 
Then the Euros flooded into the midwest in the early 1800s as per Tom Sawyer, 
cutting down almost all the mast trees to accomodate the inefficient farming 
of the time (there was a lot more farmland in 1900 than there is now). And 
everyone was eating the tasty, nutty flavored PPs. So their population 
quickly crashed. 

As I pointed out in DA, this was a good thing. We would not want huge 
masses of doves, would be worse than the starling and crow flocks we have to 
up with. They would be pest birds, pooping all over everything. An icky 
health hazard. And the PPs probably could not breed in small flocks. So it was 
either them or us. What I miss is the ivory bill. The last documented 
population was wiped out in WW II because Roosevelt refused to ban the logging 
the last river bottom virgin woods the woodpeckers lived in for war needs. So 
we can blame FDR and Hitler for that one. Whooping cranes and California 
condors were remnant post Pliestocence populations when Euros arrived. They do 
not harm and are worth saving. 

The highly specialized woolly mammoth evolved late in the Pleistocene and 
may have been vulnerable to natural loss during interglacials. But that is 
just one species. Just a few years ago geotime wise there was a spectacular 
megafauna in the Americas including multiple genera and species of mammoths 
and mastodonts, super sloths, super bears, cats, and wolves, super bisons, 
super beavers, etc living in all sorts of habitats from subpolar to tropical. 
Of course there was constant faunal change during the Pleistocene. But 
nothing like the Ameroextinction around 10K years ago. Or the Australian 
extinction somewhat earlier and only after arboriginals got there. That these 
extinctions occured at pretty much the same time those pesky humans showed 
up without the latter playing a major role is a real coincidence stretch. 
Probably the people factor was a combo of hunting and habitat modification, 
including setting large scale fires. The latter, and further habitat changes 
due to the loss of the megafauna, may have impacted the minifauna. 

Africa has the most intact megafauna because the elephants, rhinos, hippos, 
giraffes, lions, hyenas, etc evolved in the presence of evolving humans. 
Basically the big animals learned to flee and ask questions later when people 
were about. The Eurasia fauna also co-evolved with later protohumans. The 
Ameomegafauna would have had no idea what the protein hungry paleoindians were 
up to when they suddenly showed up with unprecedented long reach weapons. 
Same for the poor Aussie megafauna.