Geoscience Reference
In-Depth Information
(Ursus americanus
) that have eaten elk or other protein-rich meals, their scat is
large, flattened, and composed of pinkish masses of digested flesh and bits of bone
orfur,oriftheyateplants,itwillemitgrassyorfruityscents.Scatfromgrizzlybear
(
Ursus arctos
) is similar to that of black bear scat, only much larger, occasionally
containing little bells, and smelling like pepper spray.
Asmentionedbefore,urineisabigdealinmammalsforscentmarking,butnot
so much in birds, reptiles, and amphibians. In ratites, they “urinate” (get rid of li-
quidwaste)first,andthendefecate; meaningforthem,#1isindeedfollowedby#2.
But remember that birds use just their cloacas for waste disposal. So even though
male ratites and some other birds, such as ducks and geese, have penises—some
of which, incidentally, are worthy of applause or dread—these lack an enclosed ur-
ethra. In fact, these birds must first get their lengthy penises out of the way so they
can urinate and defecate out their cloacas.
Describing feces, whether from mammals, birds, crocodilians, or other verteb-
rates, can be enjoyable, using terms that evoke instant search images: for instance,
pelletal, cord-like, tapered, or blocky. For humans, the standard descriptive method
forfecesistheBristolscale,usedinclinical situations.Inthisscale,stoolsarerated
from 1 to 7, with 1 as separate, hard, rounded nuggets and 7 as completely fluid. In
between these two extremes, most of the weight of a stool (about 75%) comes from
water, and of the ~25% solid stuff, almost a third of this can be from dead bacter-
ia, whereas the rest can be undigested food, which if recognizable also enters into a
description. These proportions vary with all sorts offactors, such as what was eaten
or overall health. Speaking of health, feces also can contain living or dead remains
of parasites, ranging from one-celled protozoans to tapeworms, the latter reaching
lengths more than twice that of a stretch limousine.
All of these fun facts about feces and other by-products of digestion would go
to waste if it were not for also realizing how feces have changed the world. This is
the fault of plants, which as we all know by now are organisms completely unen-
cumberedbymoralsandethicsandthusarefreetoadvancetheirevolutionaryagen-
