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Re: DINOSAUR BEHAVIOR



All -

Please pardon my reactionary attitude. In my work as a paleolife
illustrator, I am striving to recreate (to the best of my abilities and
knowledge) restorations of *real, living animals*, not beasts from science
fiction or "cool monsters." To me, a more moderate picture of dinosaurian
life is no less exciting or beautiful than the kicking, leaping, flying
image that's taken hold in recent years. The most unfortunate drawback to
the "Bakkerian revolution" in my mind is the credulity of the general
public (and some scientists, too, alas) to the most outrageous and
unsubstantiated statements regarding dinosaurs and their behavior. If, in
trying to find what I consider to be a more reasonable middle ground, I
have come across as overly pedagogic, I humbly apologize. That said...

Jay Freeman raised a number of valid points in his post. Unfortunately,
this demonstrates the problem with email... I'm not writing a book here,
but a (hopefully) reasoned response that is composed and edited rather
quickly, and then sent off without any real time to reconsider the content
or phraseology. Hence...

> No bird or crocodilian species alive today - the groups that
>phylogenetically > bracket dinosaurs -- hunts cooperatively. Only mammals
>do.

is a gross misstatement on my part. Substitute "hunts in packs" for "hunts
cooperatively." To quote from a personal email to Bonnie Blackwell: While I
believe that most "cooperative hunting" behaviors attributed to birds are
at least slightly exaggerated, I am more than willing to give the benefit
of the doubt. The *smartest* dinosaurs (dromaeosaurs and troodonts), are at
best the mental equals of emus and ostriches. Emus and ostriches are
nowhere near as smart as crows, parrots, or raptors, therefore neither were
dromaeosaurs or troodonts. Mammalian behavior is on an entirely different
level than that of birds. I think the problem I have stems from the use of
the term "pack" itself. Pack behavior goes far beyond just cooperative
hunting; it has everything to do with the social structure in the pack
itself. These behaviors, as seen in wolves, are *very* complex, and IMHO
*far* beyond the intelligence levels of dromaeosaurs (see above). In a way,
though, I suppose it boils down to a matter of semantics, but in science, I
think that semantics is everything. How about if we called cooperative
hunting in dinosaurs "pride hunting" (a la lions)? Or "pod hunting" (a la
whales)? Are these terms any more acceptable or legitimate? Again,
mammalian analogues are inappropriate because of the context of the terms
employed. If theropods like _Deinonychus_ travelled together in small
*flocks* -- and we described their behavior that way -- there would be less
confusion about the degree of behaviors they could exhibit. I think an
alternate explanation for "pack hunting" dromaeosaurs is at least
*possible*, and in view of my (I'd like to think considered) opinion of
their intelligence and theorized range of behaviors based on that
intelligence, it makes much more sense.

Jay wrote:

> Other complex social behavior, in family groups that are reminiscent of
>canid > packs, is widely reported in corvids.  Less complex behavior,
>including       > mobbing, smoking (a response to predators, not to
>nicotine), flocking, and    > migrating in formation, is of course
>well-known, perhaps in a majority of      > avian species.  There are also
>a number of citations of spontaneous avian tool > use (that is, unprompted
>and untrained), and the ability of some caged birds  > -- notably parrots
>-- to learn to maniuplate locks and latches is well-known.
> To the extent that such behaviors are the subject of discussion, a
>sophist who > believes that birds are a derived group of theropods might
>argue that we have > now demonstrated by direct observation that dinosaurs
>not only *are* capable  > of behaving like lions, but in fact do so
>regularly.

Again, my fault. Of course birds exhibit social behavior, and through
inference theropods must have as well. But social behavior akin to *bird*
behavior, not *lion* (mammalian) behavior. Can birds have social structures
as complex as those of lions? And specific -- and rare -- examples of tool
use or lock manipulation by particularly intelligent birds does not seem to
me to be a basis for broad speculation about theropod behavior.

I wrote:

> Some modern birds -- raptors, psittaciformes -- are *much* more
>intelligent   > than any theropod ever was.

to which Jay responded:

>  Conjecture.

Granted, but based on what I've read and been told, I stand by this statement.

About Harris (Bay-winged) hawks... it is *not* universally accepted that
this is an example of cooperative hunting, even though it superficially
seems to be. Opportunism is equally valid an interpretation of this
behavior. And again, even if it *is* cooperative hunting, it is *unique*
behavior among birds. Picking a unique example of behavior and applying it
to other related forms is questionable. Lions hunt in prides; most other
cats are solitary hunters. What, then, can we infer about the hunting
behavior of cats?

Jay wrote:

> I will admit to awarding low weight to comparative anatomical studies of
>gross > crainal size and features; encephalization always sounded to me
>overmuch like > phrenology with a Ph.D., and seemed unlikely to predict,
>for example, such     > tool use as has been reported in corvids, who have
>a brain  the size of your  > thumb or smaller.

Again, granted, but until someone irrevocably refutes this analysis, it
seems reasonable to me to use it.

Brian (franczak@ntplx.net)