1893
April 1
(No 4)
Concord, Mass.
   Shortly after sunset a pair of Hooded Mergansers
came up river and turning in over the swamp 
behind Ball's Hill crossed the land to the Great
Meadows. These, doubtless, are the same birds that
I saw this morning and yesterday. Five Black Ducks
also passed one flying N.E. toward Bedford Swamp.
[margin]Hooded
Mergansers[/margin]
  Blackbirds were scarce during the day but at
evening a flock of 32 Rusties, the first I have
seen, passed Davis's Hill. They were followed closely
by two smaller flocks at least one of which was
made up wholly of male Red-wings. The flight
of the two species, although similar, is distinguishable
for the Rusty describes longer and easier curves
or undulations than the Red-wing whose flight
is more jerky. The Rusty is also, of course, a
slenderer looking bird and his tail appears, at it is,
somewhat longer.
All these Blackbirds were flying due north
rather high up and, I make no doubt, were
migrating on the crest of the warm wave that
reached here this afternoon.
[margin]Rusty
Blackbirds
& Red-wings
migrating[/margin]