[mou] Median arrival dates

[Paul Budde]

Dave Cahlander has actually been working on a method of reporting when
the bulk of migration happens by species.  Take a look at 

 

http://www.moumn.org/jpgraph/migration.php?

 

Of course, this is limited by the data entered into the website, and so
might be biased towards early and late dates.

 

Paul

 

 

-----Original Message-----
From: mou-net-bounces at moumn.org [mailto:mou-net-bounces at moumn.org] On
Behalf Of John Green
Sent: Friday, February 15, 2008 10:24 AM
To: mou-net at moumn.org
Subject: [mou] Median arrival dates

 

 

    This is a message from Jan Green on John's email.

 

    The MOU net discussion about bird migration dates has been 

interesting.  But there remains a question that needs to be answered.  

What migration dates do birders want - the usual or the unusual?  Or 

both?  When the data for Green and Janssen's Minnesota Birds were 

compiled, we tried to do both with the relatively meager information 

available in the early 1970's.  Obviously much more information from 

birders is available now.

    The Seasonal Report column in The Loon published first and late 

dates yearly with a comparison to the median early or late dates for the


past 20 years.  These extreme dates tell something about the timing of 

migration but they do not represent the bulk of the migratory activity 

when most birds are moving.  This can be the most significant
information.

 

<snip>

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