Concord, Mass.
1909.
April 7
  Sunny but very hazy. Light S. W. wind. "Warm as summer."
My registering thermometer did not fall below 50 degrees in last 24 hours.
It rose to 75 degrees to-day.
  Noted for first time this season: - Purple Finch male in gray plumage
at Farm, in orchard behind house, in full song through day.
Field Sparrow, male in full song in our berry pasture 8 - 9.30 A.M.
Arrivals.
  The effect of this sudden warm wave (after prolonged coldish
weather) on the movements of the birds is what might be expected.
It has caused marked & widespread activity & increase or decrease
where before matters remained almost at a standstill. The whole
country hereabouts swarmed with birds to-day and they were all
in the highest possible spirits, singing, calling, chasing one another
to & fro, from daybreak to dark. There were fewer arrivals
(only the two noted above) of species than one might have looked
for but the increase in the number of individuals was very
considerable with several species.
General migratory movements
  It is evident that the majority of our local Robin
population arrived early this morning. Hitherto the birds have
been scarce about this farm but to-day they scattered
numerously all over it singing a little & calling a great deal.
The males were almost constantly squabbling with one another,
rising straight upward in couples to a height of 6 or 8 feet &
then descending slowly to the ground keeping all the while bill to bill
& making a loud clapping sound with their wings (I heard it at 60 yds.)