Tweeters,

Since everyone else is relating their observations of Bald Eagles
hunting and killing birds, I'll add my two cents' worth to the
discussion. Two days ago, on January 23, I observed two adult Bald
Eagles-- possibly a mated pair-- hunting American Coots on Nicola
Lake, near Merritt, B.C. The locality was a small bay about 2 km east
of the hamlet of Quilchena. A flock of about 40 coots was resting on
the lakeshore, when something scared them and they all rushed out into
the bay. The source of the commotion proved to be the two Bald Eagles,
which alternated in taking swoops at the coots on the water. After
about 8 swoops, and no success by the eagles, the eagles gave up and
perched side-by-side in a dead tree near the lakeshore, while the
coots moved farther up the lakeshore away from the eagles.
A few days earlier, on January 12, Alan and Frances Vyse of
Kamloops observed 2 eagles hunting a flock of about 30 coots on Stump
Lake, the next lake north of Nicola Lake. In this case, the coots were
far more vulnerable. The lake was almost entirely frozen, with only a
small patch of open water which had been kept open by the coots. It
was questionable whether the coots even had room to take off from this
small patch of open water.
It is commonplace to observe Bald Eagles hunting coots in winter
around the lakes of the southern B.C. Interior. However, they may have
their greatest success in a situation as at Stump Lake, where coots
are isolated in a small patch of open water surrounded by ice. (In
some cases, coots even get frozen into the ice, and of course are easy
prey for eagles then.)
Even though commonplace, this hunting behavior of Bald Eagles may
surprise someone who is not very familiar with Bald Eagles, or has not
often seen coots and eagles together. There is no question that in
most cases, Bald Eagles prefer their prey already dead. However, they
can certainly be adaptable and effective predators of waterbirds, and
many eagles may rely on waterbirds as their main source of food for
months at a time.

Wayne Weber
Kamloops and Delta, B.C.
wayne_weber at bc.sympatico.ca