Re: Carnivore Energetics: Why Are Lions Not As Big As Elephants?

[jbois@verizon.net]

Dan said:
"Large mammals tend to have longer reproductive cycles, and produce fewer 
offspring at a time (usually just one). This wasn't an issue for dinosaurs, who 
could pop out relatively tiny eggs by the dozen. It is almost certainly a 
limiting factor in mammals though; especially predators who tend to live 
dangerously. If the death rate of a species out-strips their reproductive 
rate, then that species is in trouble."

But be careful to recognize that reproductive success may be mightily enhanced 
by investing development time (i.e., in the uterus).  A well-baked elephant 
baby with big brain, big size, etc., etc. may well stand a better chance of 
surviving than a half-baked dinosaur baby.  In this view, fewer offspring is 
not a "limiting factor"...but more like a superior evolutionary "choice".  
Further, I don't believe there is any physiological constraint on a large 
mammal having many small babies rather than one large one.

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Dann Pigdon
GIS / Archaeologist         http://www.geocities.com/dannsdinosaurs
Melbourne, Australia        http://heretichides.soffiles.com
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