[Tweeters] Marymoor fall raptor migration peak data

Michael Hobbs birdmarymoor at verizon.net
Fri Oct 10 10:25:26 PDT 2008


Tweets - in my Marymoor report for yesterday, I alluded to this week being
the peak of fall raptor migration at Marymoor. Well here's the data,
charting Osprey, Bald Eagle, Northern Harrier, Sharp-shinned Hawk, Cooper's
Hawk, Rough-legged Hawk, American Kestrel, Merlin, and Peregrine Falcon. I
didn't include Red-tailed Hawk, which are just so ubiquitous at Marymoor as
to obscure the data.

Week 39 40 41 42 43
#Species 2.6 2.6 3.1 2.3 1.9
#Birds 3.1 3.4 4.2 2.9 2.1
#Years 13 14 14 13 13

So this shows the average number of raptor species (#Species) and the
average number of raptor individuals (#Birds), each year since 1997
(exluding RTHA).

The #Years shows the number of years for which I have data.

I think it's pretty cool when a pattern like this becomes obvious in my
records. This peak seems very real.

== Michael Hobbs
== Kirkland, WA
== http://www.marymoor.org/birding.htm
== http://www.marymoor.org/BirdBlog.htm
== birdmarymoor at verizon.net




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