extinction

the on-going dispute of reasons for extinction.
some say climate change, as the ice age waned, others like diamond say it was overpredation.

we know for a fact that the maori people who found New Zealand in roughly 1000 - 1500 AD, did kill the giant moa birds of the islands within a few hundred years. but these are two small islands!
could this be possible on 2 much larger continents?

diamond, who might be quoting martin's work says that it could be possible if humans predated on mammoth every two months, given that at least 100 hunter-gatherers came through the ice-free corridor from alaska to edmonton.

but i still don't know which way to sway.
but i'm starting to think that a little bit of human intervention can effect the flora and fauna through direct and indirect ways.

yeah. you can kill a mammoth, and with their long gestation period, its harder for them their population to bounce back from a few hard hits.
but then if you also start modifying the environment by taking down trees and adding more carbon dioxide to the atmosphere, your climate is also going to change. so maybe if you come into a stable environment that's been running its course for at least a few thousand years, if not a million or so years, and fuck with its homeostasis, a landslide of events may result.
that initial disruption has a snowball effect until something traumatic happens and stasis is once again regained.

diamond states that since 1600 AD, that only 5 - 6 species of birds have gone extinct in North America, and only 1 in Europe. once things were under control in the US, life proceeded as usual.
somehow, amazingly even the industrial revolution didn't kill off more bird species. i guess it pays off to fly. and that's why so few flightless birds are left on the earth in only remote places like African deserts, South American highlands, and island continents of Australia and New Zealand.

i wonder if people will ever figure out, or if its true, that human activity can affect climate.
then all our climate vs. predation disagreements would be null and void.

i'm thinking of easter island. large amounts of clearcutting on the island followed by dry weather that didn't allow for forest regrowth.
but islands always seem to be an exception because of their small land area.
...nowhere for fauna to hide, from nowhere for flora to be replenished...