Silent migratories

["Colin Driscoll" <>]

My main point was that there seems to be a few weeks between the birds
ceasing to call (but still being in the area) and finally leaving. This
makes it more of a task to document significant differences in departure
dates year on year. 

Colin



-----Original Message-----
From: 
 On Behalf Of Margaret Cameron
Sent: Monday, 12 March 2007 2:54 PM
To: 
Subject: Silent migratories

from the point of view of monitoring global changes, does it matter whether
the dates are of the last birds leaving your area or the last birds going
through? presumably you have always recorded them the same way and if you
think you may now be recording the last passage migrants instead of the last
locals, maybe you were always?

Margaret

Margaret Cameron
2 Cintra Street
Eastern Heights
Queensland 4305
Australia
07 3282 9151