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Re: Endothermic Crocs in Nature



I've always thought of the term "metabolic rate" being
mass-specific. However, Webster's defines it as simply
the amoun tof energy expended in an hour.
--- Tim Williams <twilliams_alpha@hotmail.com> wrote:
> Jura <pristichampsus@yahoo.com> wrote:
> 
> >The results of automatic
> >endothermy are NOT a high activity level and
> >endurance, both of these have been shown to be
> >independent of automatic endothermy (see mako
> sharks,
> >tuna, bees, ants, and near any autarchoglossan
> lizard,
> >for examples).
> 
> Lamnid sharks (makos, great white shark, porbeagles)
> have a system known as 
> "regional endothermy".  Here's a summary:
> 
> http://www.ncf.carleton.ca/~bz050/wsphysio.html
> 
> >Larger animals do not have higher metabolic rates
> than
> >smaller animals. They have LOWER metabolic rates.
> An
> >elephant might eat a lot of food per day, but
> compared
> >to body size, it is but a tiny fraction of the food
> >consumed by a gerbil everyday. It's amazing how
> much
> >energy can be saved when one isn't just burning up
> >everything to keep warm.
> 
> I have to agree with you here.  The high surface
> area to volume ratios of 
> small mammals (and birds) means they have to eat
> much more per unit body 
> weight than a larger-bodied terrestrial endotherm. 
> In general, anyway.
> 
> 
> Tim
> 
> 
>