There's been quite a bit of talk about our "late spring" over the past
few weeks and I figured I should test the notion against past data.

I took the arrival times I've been collecting for Clatsop Co for the
past 12 years and averaged them then determined the standard deviation
(not that difficult if you have a spread sheet) and compared the average
+ or - the standard deviation to this years arrivals in Clatsop County.

AVG stdev 1999 stat
ARRIVAL

SWALLOW,TREE 58.9 7.0 62 ot
HUMMINGBIRD,RUF 61.6 9.3 62 ot
SWALLOW,VG 65.7 6.0 65 ot
OSPREY 86.5 4.8 94 late
WARBLER,OC 88.6 7.0 101 late
YELLOWTHROAT,C 93.0 5.4 100 late
TERN, CASP 93.9 4.1 90 ot
SPARROW,SAVANNAH 97.7 4.8 121 late
SWALLOW,BARN 97.8 7.8 101 ot
WARBLER,BTGY 107.9 12.0 108 ot
WARBLER,WILS 107.9 5.2 108 ot
MARTIN,PURPLE 124.7 6.5 135 late
SWIFT,VAUX'S 125.9 10.89 129 ot
WARBLER,YELLOW 129.0 2.9 128 ot
FLYCATCHER,OS 132.2 3.3 142 late
VIREO,WARBLING 133.4 6.2 128 ot
PEWEE,WW 134.0 6.2 129 ot
TANAGER,W 136.8 16.5 136 ot
THRUSH,SWAINSON'S 138.0 5.0 122 ot
GROSBEAK,BH 142.1 7.9 136 ot
FLYCATCHER,WIL 157.4 15.1 151 ot

Most species fell within one standard deviation of the average. It
would be difficult to claim they were late. This data only applies
to Clatsop County and does not look at peak movements.

In part two I will be comparing averaged peak movements from mist
net data collected at the Ft Stevens banding station to peak movement
data from this year's banding effort to see if the majority of birds
arrived late for Clatsop County.

--
Mike Patterson I don't swear for the hell of it.
Astoria, OR Language is a poor enough means of communication
mpatters at orednet.org and we've got to use all the words we've got....
Besides, there are damn few words anybody understands
Henry Drummond in "Inherit the Wind"

http://www.pacifier.com/~mpatters/bird/bird.html