Re: Birds as dino-killers, Re: Scientific Literature

["David Marjanovic" <david.marjanovic@gmx.at>]

> On Sun, 2 Sep 2001, David Marjanovic wrote:
> > Mass extinctions aren't included in normal ecology.
> > Known mass extinctions don't grade into background extinctions AFAIK.
>
> I don't believe "mass extinction" has a definition--apart from lots of
> things becoming extinct.  One person's mass extinction may be another's
> not-so-mass extinction.  For example, I show my students a graph of
> species diversity vs. geological time--the K/T extinction really doesn't
> stand out from many smaller extinctions.  And they _never_ guess that htis
> is the one in which the dinos bit it.

All such graphs I know have quite an outstanding peak at the K/T-boundary...

> > There were no small adult pterosaurs during the entire LK AFAIK, anyway
not
> > in the Maastrichtian.
>
> Why not?

No idea, really, just none are known :-)

> > > Egg-opening plays second fiddle to hatchling snatching as a predatory
> > > tactic in bird on big bird predation.
> >
> > Sorry, my error. However, incredible lots of birds and mammals are
> > occasional nest raiders today, so much that nests in trees are anywhere
from
> > safe. Yet birds show no sign of decline. What is happening here?
>
> Could you entertain the hypothesis that many song bird species are in
> steep decline due to crow predation on nests and chicks?

No. Because crows have evolved long ago and all those other songbirds are
still there. There aren't just crows but also magpies and apparently every
single arboreal mammal species such as squirrels, monkeys and whatnot. There
are endangered songbird species over here -- all endangered by man (habitat
loss etc.), not one by a nest predator.
When I step out of the door, I see lots of blackbirds (population densities
of one every few square meters IMHO) and relative lots (one every few days)
of magpies (famous nest raiders, too famous in fact). Squirrels are also
here (but few because high trees are rare). I can't see any decline.

> > So I repeat: "and that *Gobiconodon* and *Repenomamus*
> > somehow failed to have similar effects." How?
>
> I predict--but don't know--that sizes for latest Cretaceous mammals were,
> on average, increasing.  John Alroy has data on this.

OK. So I'll wait for the data :-)

> I've tried to read
> his graphs but they are not that clear.  They appear to show an increase
> up to the K/T.

While I don't know his graphs, such graphs are always heavily influenced by
the quality and knowledge of the fossil record, so they _might_ tell nothing
at all.

********************************************
> Paleontology already has an on-line and free journal, which has had
> difficulty getting enough submissions to publish on a regular basis.  The
> last issue was published in November of 2000, and Norm MacLeod sent out an
> email to Vrtpaleo a while ago inquiring as to why so few manuscripts have
> been submitted.

Palaeontologica Electronica is IMHO just too little known at present, and
people prefer high-prestige journals like Nature, Science, JVP and such. May
change :-)

> Another question on exclusive on-line publication is what will folks do
who
> don't have Internet access?   Not even a (heaven forbid!) trip to the
library
> would help.
>
> Mary
> mkirkaldy@aol.com

Every library in Vienna, including school libraries, has AFAIK at least one
computer with Internet access, all rooms of the university library (strewn
across the city) have several. Is this different in the USA? ~:-S
Even if, every university will give the staff at least Internet access
somewhere in the university's buildings, no?
BTW, the number of Internet users is rising so fast (are we already 100
million?) that in the long run I wouldn't worry about that. May I repeat the
rather simple-minded sayer "this is the future" :-)