How do they know?

[Brian Murphy <brmurphy@mindspring.com>]

I have not done much wader birding so I plan to bird the Falls and Jordan 
Lake mud flats Friday.

So a question arises - who told them the water levels were low?

Where did they come from?  The coast, or are they just traveling slowly 
south overland and hoping to get lucky?

My son suggested they must send out scouts like ants.  :-)

Do coastal birds occasionally wander inland to "check" conditions?
Perhaps they notice the lower river levels or salinity changes in estuaries?

Are there well-researched answers to any of these questions?

Brian


Brian T. Murphy   www.mindspring.com/~brmurphy
Science Dept.
Millbrook High School    http://mhs.wcpss.net
         AP Environmental Science   http://mhs.wcpss.net/Murphy/apes/
           Physical Science  http://mhs.wcpss.net/Murphy/PhysicalScience/
Raleigh, NC, USA