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Forty years of predation on Serengeti.



Important paper with some relevance (perhaps) to dinosaurs: Sinclair,
A.R.E., Simon Mduma and Justin S. Brashares 2003 Patterns of predation in
a diverse predator--prey system. _Nature_ Vol 425, pp.288-290.
Concludes that smaller prey are target of diverse predators (many preying
opportunistically) and are limited by predation.  Larger prey--at a
threshold of around 150 kg (e.g., giraffes, rhinos, and elephants)--are
somewhat immune and are instead limited by food availability.  Rhinos and
elephants suffer almost no predation and even their juveniles are prey
"only rarely".

This must be a huge contrast with dinosaurs--even very large
dinosaurs--whose very small juveniles must have been fodder for diverse
predators.  Because of this, Mesozoic ecosystems were entirely different;
reproductive dynamics, pred/prey ratios, etc., etc.

Interesting that when, during time of heavy poaching predators were
removed  from Serengeti system, numbers of small prey went up...but large
animals remained limited by food supply!  How does this affect the vaunted
advantage of large size: ability to process large quantities of food?
I mean, who cares if one can process vast amounts of
food, if vast amounts of food are unavailable?  One would have to argue
there was more food in the Mesozoic.  Otherwise, like the elephants,
predator-resistance seems its prime value.

Enough rumination.