[Tweeters] Truly special habitat - or just 'learned locations'?

[jimbetz at jimbetz.com]

Hi,

   Have you been to the East 90?  There are Harriers, Short-eared  
Owls, Eagles, Kestrels, and
even the occasional Red-Tailed Hawk.  Not just a few but  
"concentrated" (common to see them
there this time of year and for the last 4 years that I've been going there.

   However, not very far away (less than a mile or so as the owl  
flies) is the West 90 and
the road from there to Samish Island.  A lot of this seems, to this  
observer, to be
essentially the same habitat as the East 90 ... but there is no where  
near the concentration of
birds and very few to zero Short-eared Owls ... ???  I have seen  
harriers in the section
between the "wiggle in the road" and Samish Island.  And often an  
eagle or a hawk ... but
I've never seen a SEOW in that section.
   You would think that the concentration of just the harriers and  
SEOWs would deplete the
voles to the point that the birds would move on to different places.

   Any ideas on why this is true?  Especially on why there are so many  
more birds at the
East 90.  Yes, I get it that it is all about the voles.  I just don't  
understand why
the area around the East 90 has so many more voles.  To my eye the  
habitat is the same -
the areas between the West 90 and Samish Island has been fallow for a  
similar amount of
time, has corn fields near by, has the same amount of water, etc.
                                                                        
      - Jim