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Re: Vegavis gen. nov. - new anseriform in today's Nature



On Sun, Jan 30, 2005 at 11:10:25AM -0500, John Bois scripsit:
> 
> Bois said:
[snip]
> > > ostriches and rheas survive just fine...
> > > Even after suffering greater than 90% nest/chick
> > > predation to the first year.
> 
> > Yes, even then. They are r-strategists. Like, for example, sauropods.
> 
> ...that were replaced on some continents by the relatively K strategists,

But they weren't.  Sauropods didn't like damp lowlands, which is where
the majority of the known hadrosaur -- helya, _iguanodontoid_ -- fossils
are from.  Sauropods are known from NorAm in the Cretaceous, just not
from Hell Creek.

> hadrosaurs.  Are we looking for an out-of-planet experience for this?

Ostriches are not more of an R-strategist than a hadrosaur -- ostriches
definitely do care of the young, where that's only inferred for one
hadrosaur.  There's every possibility of variation in nest care among
them.

As a general rule, clutch size ties tightly to mortality and resources;
those big hadrosaur clutches indicate some mix of lots of mortality and
plentiful food, or at least a mortality curve that stays under the food
supply as a reliable matter.