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Re: Orenstein's pedestrian arguments.



John Bois wrote:
> 
[snip]
> the almost total absence of flight-less birds in the
> small-animal niche reflects the non-competitiveness of this body plan,

How many diurnal  mammals are there on the small-animal
niche?

> Here is my preconceived notion: dinosaurs of the late Cretaceous got
> bigger.  There was none smaller than a chicken. 

Similar question...

[Here Mr. Bois is replying to Mr. Orenstein]

> I am happy to learn this.  Is it possible in your world to impart
> knowledge without pomposity?  Is it possible for you to accept
> that others may not know as much as you about certain things without
> hurling abuse at them?  Knowledge should be a gift.  You use it as a
> knife.
> 

Now Mr. Bois, we don't need this... 

>Relative to a biped of equal mass, a quadruped
>can dig better burrows (is it only the kiwi which digs burrows), 

Can you elaborate on this? There are other birds that dig burrows 
to make nests, even a few flying birds (I don't know their English
names). Some birds and a few mammals (hares) make hiding places on the
ground were they stay when they are not active. Are the few bipedal
mammals able to dig holes?

[BIG SNIP (Mr Orenstein and Mr Bois make nice remarks about each other
again)] 

> But they are _not_ as well adapted to this
> micro-niche as are mammals, lizards, and snakes.  This is true because
> they must keep their wings in order to escape it! 

I don't understand the reasoning... Being able to fly to evade 
predators and being able to walk efficiently to forage is a big
advantage. Birds took over the ground diurnal micro-niche, probably 
if bats capable of walking and flying efficiently could evolve they
would take most of the ground nocturnal micro-niches also. As I see it
one of the advantages of being small is that it allows for efficient
diurnal/nocturnal specialization, you just hide/stay quiet during the
rest of the day. One can not really compare strategies between birds 
and small mammals.

Lizards and snakes are different, they need less foraging so they are
less vulnerable.

Birds and dinos, who knows, maybe birds out-competed all small-sized
non-avian dinos and in a certain way are responsible for the dino
extinction at the KT event.

I'm answering to this thread mostly to ask you guys to be more careful
about the personal remarks. Some people have already flamed someone for
being playful, this is almost as bad!

Best regards

D. Maia                         Dalmiro.Maia@obspm.fr