Among duck hunters it's axiomatic that birds fly lower in bad weather; the explanation being that, when atmospheric pressure is low, the densest air, which provides the best support, is near the ground. Makes sense to me.

Joel Martin
Catonsville, MD
 


-----Original Message-----
From: June Tveekrem <>
To: 
Sent: Tue, Oct 27, 2009 1:46 pm
Subject: [MDOSPREY] Fwd: [ENTOMO-L] Why do swallows fly low before rain


Since the post below involves birds as well as insects, I thought I'd see if birders can offer some insight. 
 
June 
 
-- June Tveekrem 
Columbia, Maryland 
tweekiebird|AT|southernspreadwing.com 
http://SouthernSpreadwing.com 
 
-------- Original Message -------- 
Subject: [ENTOMO-L] swallows flying low 
Date: Tue, 27 Oct 2009 19:12 
From: Toomas Tammaru <> 
To:  
 
 
Dear colleagues, 
 
I was approached by the editor of a popular book and asked to 
comment, from the entomologist's point of view, on the well-known 
phenomenon that swallows fly low above the ground before the onset of 
rainy weather. I was not able to comment. 
 
May anyone know why exactly is this the case: 
- do the swallows follow their prey items? 
- if yes, which insects fly low above the ground before rain and 
why? Do the insects 'decide' to do so (an adaptive response to what?), or 
are they just unable to fly higher under such conditions? 
 
With apologies, Toomas 
 
************************** 
Toomas Tammaru 
professor of zoology 
http://www.ut.ee/~tammarut