Larus philadelphia.
Lake Umbagog.
1907,
August 14.
  A Bonaparte's Gull appeared off Lakeside this afternoon,
during a heavy blow from the N.W.  It coursed about over the open
lake and entered the cove at the mouth of the Cambridge, but did
not approach the land closely. It flew most of the time at a 
height of 20 or 30 feet above the water, but every now and then it
would swoop almost straight down in the manner of a Tern. On
reaching the surface of the water it would either hover just above
it for a moment apparently to pick up some floating object or
would alight and swim about, perhaps for several minutes, before
taking wing again. It was a beautiful creature, appearing snow
white when seen against the dark green background of the forest,
and very buoyant and graceful in all its movements. The behavior
which I have just attempted to describe is characteristic of this
species of Gull. By it one may usually distinguish the bird from
the Common Tern for which it is likely to be mistaken at a distance.