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Re: Forster's papers on Triceratops

From: Betty Cunningham <bettyc@flyinggoat.com>

 >   Would it make more sense to say that in an animal with a
 > harem-type herding system, females would be more numerous >in herd
 > situations< than males, unless they followed something along the
 > lines of elephants with male herds and female herds?

Generally, in harem type animals the *total* population of males
is less than the total population of females, often due to a much
higher mortality rate in males.

Where the males and females stay in separate herds off-season, or where
the bachelor males band together in small herds, males may be *locally*
more common.

 >   Does this seem more likely, or would the male population show up
 > somewheres else that I'm not thinking of?  The herd situations we
 > seem to have are generally one species prodominant, correct?  What
 > about sex morphs?

It depends alot on herd structure.  There are many different systems.

Horses use one dominant male and several adult females with colts. The
bachelor males live in marginal territories that are not productive
enough to support reproductive females, sometimes in small herds.

Bison, on the other hand, appaently lived in same-sex herds except during
the rutting season.

Still other animals live in large mixed-sex herds with many individuals
of each morph. (I believe that wildebeest may do it this way).

Unfortunately for my idea of the two species being sex morphs, the
T. horridus type includes morphs that correspond to both genders
based on the dimorphism in Chasmosaurus, and the *rarer* T. prorsus
is known only from morphs that should be female according to the
pattern from Chasmosaurus.

swf@elsegundoca.ncr.com         sarima@ix.netcom.com

The peace of God be with you.