Small theropods in large groups

["Mike Styzen Shelf Expl, 588-4308" <mstyzen@nos40eq.shell.com>]

Hi all,
I was on my way downtown for Mardi Gras yesterday morning. On the
neutral ground (a wide boulevard,there is an unusual dialect spoken
here) of West End Blvd. I saw what had to be the biggest group of
robbins I'd ever encountered.  They were on about a one foot spacing
through the entire length of the street.  This patch of ground is about
100 yards wide and the street is a couple of miles long so you can  get
the picture, we're talking about a big bunch of birds (or avian theropods
if you wish).  It's not unusual to see large groups of these birds
around here in the winter time, but I was supprised to see it the first
time.  In the northern US, where I grew up, and where this species
spends it's summers, you never see more than a pair of robbins.  In
fact they aggressively defend their territory against all other members
of their species.  
Now as I am a paleontologist I made them all dead in my mind and
started making interpretations.  If I made the winter population dead
here, and preserved them, I'd see a pack (or flock) and might even
assume that they were doing something as a group.  I think they were
really eating crane flies which are annoyingly abundant around here
this time of year.  If you made the summer population dead you'd see
isolated hunters.  
So, I mused while catching beads and watching the spectacle, maybe
finding groups of predators dead together doesn't mean what we think. 
Could have to do with migration patterns, mating behavior and prey
density... They could be hunting cooperatively too...Have to give it
more thought.
Mike


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|     Michael J. Styzen                   Phone:  (504) 728-4308        |
|     Shell Deepwater Development Inc.    Room:   OSS-3202              |
|     P.O. Box 60833                      E-mail: mstyzen@shellus.com   |      
|     New Orleans LA  70160                                             |
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