Concord, Mass.
1900.
May 10
  Clear with high N.W. wind. Bitterly cold with
flurries of snow in P.M. Ice thicker than window glass
found last night on the W. Bedford side of the flooded
meadows & Pat had to break a way through it for
his boat early this morning. On this side of the river
we saw no signs of frost & my wild flowers were all
uninjured. The registering thermometer at the cabin recorded
extremes of 30 degrees - 60 degrees. At 5.30 A.M. it stood at 34 degrees, at
7 P.M. at 37 degrees. I do not think I have ever known
such cold weather in May before.
An exceptional
cold snap
  Its effect on the birds was at once interesting
and puzzling; interesting because it drove them all
from the woods to open & sunny but sheltered places
close to the river where they were most conspicuous
and exceedingly tame; puzzling because in spite
of the cold which began early last evening there was
apparently a well-marked migration during the night.
At least we had a new lot of birds at Ball's Hill
to-day. The arrivals were Turdus a bicknelli (a small,
rather shy individual, very dark in coloring, that visited
the cabin at morning and evening) T. swainsoni (one,
very tame & absolutely identified), Dendroica striata
2 adult male male in the brush by the river
Arrivals
  Other changes were a marked increase in the number
of Water Thrushes & White-throated Sparrows and a
decrease of fully fifty per-cent in those of Black & White
Creepers, Chestnut-sided, Usnea & Nashville Warblers and
Least Flycatchers. The Yellow rumped & Yellow Palm
Warbler, Redstarts & Swamp Sparrows were in about
the same numbers as yesterday. I saw no Tanagers
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