[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: The Final Days



From: "David Marjanovic" <david.marjanovic@gmx.at>
>
> Crocs are ectothermic and can therefore fast on end, more or less.
Endotherms
> can't do that without special adaptations (e. g. hibernation). And who
says
> that any adult croc survived, BTW. Maybe the only surviving individuals
were
> insect-eating babies of 1/10 or less adult length.

But adult crocs have significantly lower food requirements per unit body
mass than juveniles: a good-sized adult can fast two to three times as
long as a juvenile (approximately 18 to 22 months versus 6 to 8 months).
Also bear in mind that adults (of extant species at least) _primarily_ eat
small prey (fish, crustaceans, small mammals, even large insects) so their
food supply in freshwater may have been more reliable. Being generalist
predators certainly helped, but it depends on the time scale they had to
survive through. A mature female of the larger extant crocs has a
reproductive life of roughly 40 to 50 years (reproductive senescence kicks
in eventually), which assuming she could survive that long would certainly
help overcome problematic times. There are examples of extant croc species
not breeding for over 30 years, then being placed with a male and producing
viable eggs.

Another thing: small juvenile crocs are finger food for a wide range of
critters. If food were scarce, you'd have thought the juveniles would be at
even greater risk of predation.

Adam Britton