Concord, Mass.
Ball's Hill
1900.
May 29
  A perfect day with almost no wind. Very cold 
last night. The farmers inland report ice & the probable loss
of the strawberry crop. Ther. at cabin 35 degrees -73 degrees.
Weather.
  I was in the woods on and about Ball's Hill most of the 
forenoon and in the afternoon visited Davis's Hill. Apparently
all the birds which were here yesterday remained over and an
immense number arrived from the South during the night.
At least the woods were swarming with birds to-day throughout
the Ball's and Davis's Hill region. Most of the unmistakeable
northern migrants were Black-polls, Canadian Warblers and 
Water Thrushes. I saw at least fifty individuals of each of
the first two, the majority being females. There were two
large Gray-cheeked Thrushes and an Olive-back at Ball's
Hill. Traill's Flycatchers were scattered about along the river
front & across the river on the West Bedford shore. I
could not count them accurately as they were continually
shifting from place to place but there were certainly
three or four. I wonder if the reason why they are such
late migrants is that they do not like to move northward
until the thickets are in nearly full leaf. Their shyness
and love of concealment would suggest such an influence.
I did not succeed in catching sight of one to-day although
I tried repeatedly to follow up the pip call which was
so constantly in my ears.
North-bound
Warblers,
Thrushes etc
arrive from
the South in 
extraordinary
numbers &
variety. 
  Shortly after breakfast I started a beautiful adult male
Mourning Warbler directly in front of the cabin. An hour
later I saw him half way to the bars and in the
afternoon the Misses White & I found him in the swampy
thicket E. of the cabin. He was silent, sluggish &
very tame allowing an approach to within three or four
Mourning
Warbler.
106