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

RE: Theropod "migrations"



Hungry animals eat available food.
Well-documented cases:
1. Farley Mowat spent a lot of time observing wolves hunt mice.
2. Holes in fossil ancestral hominid skulls once interpreted as evidence
of homicide have been shown to fit the dentary of a leopard quite well.
3. The latest issue of Amateur Photographer contains a reasonably
reliable anecdote of a photographer who became a prey animal for
the wolves he was photographing. He escaped by using his flash.
4. In Pennsylvania and New Jersey black bears raid bird feeders
regularly.
5. Hyenas can eat marrow extracted from the bones of 
dried carcasses.
Recommended reading:
 The Behavior Guide to Africa's Mammals : Including Hoofed
                     Mammals, Carnivores, Primates [Paperback] 
                        By: Richard Despard Estes,
available from Amazon.com
-Gus Derkits
> ----------
> From:         Thomas R. Holtz, Jr.[SMTP:th81@umail.umd.edu]
> Reply To:     th81@umail.umd.edu
> Sent:         Monday, April 26, 1999 1:12 PM
> To:   jdaniel@aristotle.net
> Cc:   dinosaur@usc.edu
> Subject:      Re: Theropod "migrations"
> 
> At 11:56 AM 4/26/99 -0500, Joe Daniel wrote:
> 
> >> That is the point of the comment "meat is meat": for most carnivores,
> it
> >> doesn't matter if it feeds on the meat from a local animal or the meat
> of
> >> animal from another part of the world.
> >>
> >
> >This is not really true. Physiologically, sure. Behaviorally, no. Almost
> all
> >predators have a "menu" of prey items that they will hunt. Animals that
> are not
> >on that list are usually ignored. Sometimes if the predator is in
> extremis it
> >may go after something that is not normally a prey item but this is the
> >exception, not the rule. People are not safe from bears in the woods not
> because
> >the bear thinks of us as food, but as competitors. Tigers and lions don't
> make a
> >habit of attacking and eating people usually until they are old and
> unable to
> >hunt their regular prey and even then it is rare. These are just as
> examples,
> >not meant to be an exhaustive defense.
> 
> While it is true that many predator species have a certain range of
> potential prey items (based often, but not exclusively, on size).
> Furthermore, predators can establish themselves in new ecosystems where
> none
> of their home "crop" is present quite easily if artificially introduced
> there (as can, as previously noted, can at least some domesticated
> herbivores).
> 
> It would be interesting to find out to what extent the idea that "big
> predators don't habitually hunt humans" is/was true in pre-village human
> societies...
> 
> >So the point of this is that yes, predators do follow the ranges of their
> prey
> >species. but, since they usually have more than one prey species, the
> predators'
> >ranges can be bigger than the prey species.
> 
> And again, sometimes *vastly* bigger, which was the point of this
> exchange.
> _Panthera leo_'s old range included southern Europe, almost all of Africa,
> and much of western Asia prior to the historic reduction in distribution.
> How many bovid species have as big a range?
> 
> In any case, I hope we can try and shift the topic back towards dinosaurs
> soon...
> 
> Thomas R. Holtz, Jr.
> Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
> Dept. of Geology              Email:tholtz@geol.umd.edu
> University of Maryland        Phone:301-405-4084
> College Park, MD  20742       Fax:  301-314-9661
>