Re: Phorusrhacids killing large mammals in National Geographic Channel

[Raptorial Talon <raptorialtalon@gmail.com>]

> As far as I knew, if a lion is in the area, the ostrich gets out
> leaving the eggs. The few tapes I saw on such interaction always show > the 
> ostrich running away. I read in an old number of the "Reader's Digest" of an 
> ostrich breaking the backbone of a domestic dog.

Well, naturally fleeing will normally be the best option, but I was
referring to cases of being cornered. And maybe not lions
specifically, but large threatening animals, anyway.

> The largest representatives of the native South American mammalian
> herbivores are Plio-Pleistocene, as far as I know, so the previous
> South American fauna had fewer large representatives.

Yeah, but still generally good-sized animals, regardless. At least
deer-sized, IIRC.

By the time of
> Titanis, there is other report of a phorusrhacid in Uruguay, South
> America, suggesting the group was at least still widespread.

Wasn't suggesting they weren't widespread at that point, just that the
timing is curious (AFAIK) . . .

Regarding
> the extinction of the big birds, I do not know if we can blame so much
> the effect of the large northern carnivores as the reason which
> extincted all the megafauna, Northern and Southern, carnivorous and
> herbivorous. For the largest felids, canids and ursids extinguished
> also in South America.

Note, though, that phorusrhacids actually died out quite a bit earlier
than the rest of the megafauna - maybe even a couple tens/hundreds of
thousand years, if memory serves. Too early to be victims of the main
extinction pulse, at the very least.

 Notably, smaller representatives of those taxa
> survived, as did smaller relatives of phorusrhacids (seriemas). The
> competitive scenario does not explain so well why seriemas were not
> displaced by foxes and small cats.

Seriemas can fly, no? That seems like it could be quite important. Not
sure about differences in nesting habits, but that could be relevant
too. And there were phorusrhacids not really all that much bigger than
seriemas, IIRC, so maybe they *were* outcompeted/had their eggs eaten
by by canids/felids/mustelids.

Mostly just speculation on my part, of course.