[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: dinosaur fasting ecology
On Mon, 11 Feb 2002, David Marjanovic wrote:
> > Galapagos tortoises can fast up to one year, and Nile crocodiles and polar
> > bears for several months. If one scales this up, large sauropods might
> > survive in the barren desert, if every 2-10 years there was a rainy
> > season when animals fed and bred.
> You can't scale that up. It works only for ectotherms. Polar bears can fast
> that long only when they hibernate.
Of course there is a correlation between body size and metabolic rate in
endotherms. Compare shrews and hummingbirds with humans. I am leaving
aside question, whether sauropods etc. were endotherms or ectotherms.
Only polar bear females "den", which is not true hibernation - their body
temperature falls only several degrees, animals move, give birth and care
for cubs. Males can lower their metabolism and fast for several months
when moving around, "hibernating on their feet". Other fasting endotherms
are other bears, whales and emperor penguins (hard thing, because all
have to keep body fat for insulation).
You got me. Unfortunately we do not have living oviparous land-living
endotherms the size of large dinosaurs to study. Obvious fault of