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

[Dann Pigdon <dannj@alphalink.com.au>]

The answers to the subject line are easy: 

1.) Lions don't prey on adult elphants (and rarely on juveniles, as a 
general rule). They just don't need to be as big as them. 

2.) Lions mostly live in groups, so can hunt animals larger than themselves 
with little problem (in fact, the combined mass of a pride is probably 
greater than even their largest prey item). 

3.) Lions make a very good living targetting prey considerable smaller than 
elephants. If lions became solitary, grew to the size of elphants and 
started preying on them, they'd be limiting their food supply considerably 
(since an elephant-sized predator would have trouble catching much smaller 
prey). Better to hunt the more numerous smaller animals than the occasional 
behemoth. 

4.) 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. 

___________________________________________________________________ 

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