Concord, Mass.
(Ball's Hill.)
1900.
May 9
  Early morning clear & warm with fresh W. wind.
Clouds began gathering by 9 A.M. and from 10 A.M. to
noon it rained heavily & continuously. Afternoon cloudy
with wind shifting to W & rapidly falling temperature.
The. 65 degrees at 5.45 A.M., 51 degrees at 7 P.M. Extremes (registered)
48 degrees - 80 degrees. 
  Arrivals: - Helminthophila chrysoptera male *, Dendroica maculosa 
male*. D. blackburniae male in very high plumage, D. discolor male *,
Sylvania pusilla male *, Piranga erythromelas male female male male male*, Icterus
galbula 2 * male male, Falco columbarius female, Actitis macularia 1; all
except the Actitis seen either on or very near Ball's Hill the
Prairie Warbler being the first that I have ever noted
there and the Golden wing the first male that I have heard
singing there.
Arrivals
  As nearly as I could make out most if not
all of the North-bound migrants which were here
yesterday departed last night but their places were more
than filled by fresh arrivals from the South. Indeed the
bird-wave which flooded the country to-day was one
of the most remarkable that I have ever noted especially
at so early a date. At least 300 small birds spent
the day on Ball's Hill and in the afternoon I found
nearly half as many more on Holden's Hill while every
thicket or cluster of trees held a dozen or more.
By far the greater number were Warblers and of these
the Chestnut-sides, Yellow-rumped, Black & White Creeping
Nashville, Usnea and Maryland Yellow-throat were the more
numerous. The flight of Chestnut-sides & Creepers exceeding
anything that I have ever witnessed before. In all
A great
bird-wave
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