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DINOSAUR BEHAVIOR



Jay Reynolds Freeman wrote:

> I saw _JP_ nine times, and loved it for its depiction of interesting and
>> plausible behaviors, notably of the outsize _Velociraptors_, whose
>repertoire > of actions seemed lifted straight from _Pantera leo_ courtesy
>Joy Adamson and > Mark and Del Owens.

and Jonathon Woolf wrote:

> In fact, one of my pet peeves about a lot of dino-science today is that some
> people, Bakker for instance, seem to want to make dinos into superbeasts,
>as  > if they had the fighting ability of Bruce Lee mixed with the
>tactical         > abilities of a wolf (which are considerable).

Jay, I certainly defend your right to enjoy JURASSIC PARK, but your idea
that any of the behaviors depicted in that movie are "plausible" needs to
be questioned. Dinosaurs were *never* capable of behaving like lions. And
Jonathon, thank you for articulating something that's bothered me for quite
some time as well: the "Bakkerian Superbeast" model of dinosaurs *is* way
over the top, and is no more believable or realistic than the swamp-bound,
sluggish reptilian view that Bakker himself has fought so hard to dispel.

Ah well, once more into the breach...

No bird or crocodilian species alive today - the groups that
phylogenetically bracket dinosaurs -- hunts cooperatively. Only mammals do.
Therefore, assigning mammalian traits to dinosaurs is a practice that is
questionable at best, since there is no relation between the two.
Furthermore, even in mammalian groups, only a figurative handful of
predators hunts cooperatively -- lions, Spotted hyenas, wolves, African
wild dogs, dholes, dingos, and Bush dogs habitually hunt in packs; Canada
lynx, coyotes, and two of four species of jackals -- mosttimes solitary --
also occasionally hunt in this manner. Worldwide, there are 35 different
species of cats, but of all of them, only one -- lions -- always works
together in a group to bring down prey for all to share; all other cats are
solitary hunters. The dog families fare somewhat better, with 8 cooperative
hunting types (also out of 35 species), but it must be remembered that
while wolves *will* hunt caribou, deer, and moose, their main diet consists
mostly of small rodents, primarily mice. The pattern thus discerned from
mammalian predators seems to indicate that pack or pride hunting is the
exception, rather than the rule. How, then, did all *dinosaurian* predators
become "pack" hunters, which is the popular notion? The cold hard reality
from observation of extant species is that the ability to hunt
cooperatively is strictly a mammalian one -- and rare even then -- and that
the bird or crocodilian brain (and thus through inference the dinosaur
brain) is incapable of the higher functions necessary to perform this task.
Regarding the intelligence of some of the smaller theropods, studies of
fossilized braincases give good indication as to the size and complexity of
their brains and it has been stated that dromaeosaurs and troodonts --
generally considered the *smartest* dinosaurs -- are about as smart as
modern ground birds such as ostriches and emus. This is hardly a testament
to the intelligence of the theropods, however, since ostriches and emus are
as dumb as doorknobs compared to mammalian predators. Jim Farlow, long
known for his work with these birds, has told me (pers. comm.) that "Having
worked with emus and ostriches, I'm not convinced that they are
particularly intelligent when compared with pro football players, toasters,
and rocks." How, then, does an animal with an *extremely* limited
intelligence have the cognitive faculties to conceive and execute the
behaviors of pack hunting? Given that birds *do* congregate in flocks,
various-sized flocks of theropod dinosaurs does seem a more-than-likely
assertion. But flocking behavior must not be confused with "pack" behavior;
the two terms are not synonymous. Flocks of birds, while they may feed
together, do not hunt and bring down prey cooperatively in the same manner
as do lions and wolves. Some modern birds -- raptors, psittaciformes -- are
*much* more intelligent than any theropod ever was. Male and female raptors
are known to circle together searching for prey, but even they do not both
attack an animal simultaneously to kill it and then share the spoils.
Bay-winged hawks, despite lots of press to the contrary, exhibit behavior
that is really more opportunistic than cooperative; yet, even to give them
the benefit of the doubt, they are alone in this behavior in the avian
world. It is also debatable whether aerial hunters are good analogues for
behavior patterns of strictly terrestrial predators. A better analogue to
theoretical dinosaur behavior is something like African ground hornbills.
The ground hornbills -- like theropods, cursorial hunters -- will hunt
together in a familial group, but they are only really foraging together,
not hunting cooperatively. A behavorial model such as this is much more
useful and realistic than any mammalian one, and since true dinosaur
behavior is unknown -- and probably unknowable -- the only models we *can*
use to even *speculate* about their behavior are those that are observable
in the modern world; it would certainly seem more reasonable to use models
that are at least related to the animals under discussion, and are
therefore more applicable. If this leads to the abandonment of some
cherished ideas about dinosaur behavior, then so be it. *Real* science is
always far more interesting than science fiction, if not as popular.

Brian (franczak@ntplx.net)