No, not denser, but avian bones are hollow and thinner walled (it was 
necessary for avian ancenstors, the dinosaurs, to lose a lot of superfluous 
weight to get airborne) ... they are not only thinner, but because they are 
hollow their walls are subjected to decay from without and within (thus, 
they are digested by aerobic soil microbes at a rapid rate). The physical 
differences of density and thickness and SOLIDITY of mammal bones makes them 
more resistent to decay ... and they start with more mass, as well, thus it 
takes the same decaying processes longer to consume them.

~~~~~~~~~~~~~
"There is also an artificial aristocracy founded on wealth and birth, 
without either virtue or talents ... The artificial aristocracy is a 
mischievous ingredient in government, and provisions should be made to 
prevent its ascendancy."

- Thomas Jefferson (1743-1826)
----- Original Message ----- 
From: "Carol Serr" <[log in to unmask]>
 Are
> small mammals bones just more dense than those of fowl?
> Out in the desert, near the shore of now dry lakes...we do find more
> avian remians...but, I would expect the preservation to be better there
> too...dryer.