Cambridge, Mass.
1902
August
(No 3)
for this is certainly much bickering & jostling in respect
to the choice of perches. Before it has become quite
dark these sounds cease and after the roost has become
quiet and the birds are settled for the night one may
walk quickly and rather noisily along the flagging path
that passes through the lines without disturbing them.
Few birds which assemble in such large numbers as so
little subject to panics. Indeed all the Robins usually
come in and take their places without signs of fear
or anxiety but twice during the present month there
has been a general alarm sounded among them as 
late as 9 or 10 o'clock and on one occasion it was
quickly followed  by the roar of wings as large numbers
took flight nearly at once. I was unable to ascertain 
the cause of their fright but it may have been due
to the approach of a Screech Owl which we frequently
heard wailing in the Garden at about this time.
With the first signs of daybreak the Robins began to
stir in the roost and to call to one another while
during July the old mobs frequently sang. As soon as it
is broad daylight they began leaving - as they came - 
in detachments and singly. The process of evacuation of
the roost consumes half an hour or more and
some of the birds longer there, or in other parts of
the garden, until after sunrise. I have had no
opportunity for ascertaining how large an area of
the surrounding country is drawn upon by the
population of this roost.
Robin roost in Garden
70