Concord, Mass.
1906.
Sept. 5
  Brilliantly clear & pleasantly cool with light easterly to
westerly wind.
   About 8 A.M. a large flock of Chimney Swifts which
I think were without doubt migrants from further north appeared
on Holden Meadow flying at a considerable height and in every
direction evidently looking for insects. There were fully fifty birds
in the flock. Soon after I discovered them a brisk easterly
wind started and the Swifts drifted before it towards the westward.
I did not see them again but at evening a little flock
of five passed Ball's Hill flying towards the east.
Large flock of migrating Swifts
  A flock of about 125 Swallows appeared over the river
opposite the cabin shortly after sunset and flew back & forth in
a nervous, excited & apparently aimless way until nearly dark.
I think they went to roost not far off. Judging by their
notes the majority were Barn Swallows but I heard the
unmistakable flight calls of Eave Swallows many times &
those of Tree Swallows more than once.
Mixed flock of Swallows
  H.W. Henshaw & I had a fine opportunity to watch a female
Cape May Warbler this forenoon. We found it in Birch Field about
10 o'clock and had it under observation, usually at close range,
for 15 or 20 minutes. It was in low gray birches feeding busily
(apparently on the greenish birch Aphis) in company with a Black
poll Warbler & a Black & White Creeper. The Cape May was
very tame & sluggish paying little or no heed to our near
presence & spending minutes at a time on the same branch
picking off Aphidae from the leaves & twigs in a deliberate
leisurely way. It was in full fresh autumn plumage. The fine
brownish streaking of the breast was conspicuous & we saw the greenish
yellow of the rump clearly. In short the bird was absolutely identified by us. 
Cape May Warbler