I was supposed to be leading a walk today that was cancelled, and not having
time to go to Delaware for the Wood Sandpiper, decided to check my nestboxes at
Huntley Meadows. Despite the rain, the birds were very active. Conventional
wisdom says to pair boxes together because it permits Eastern Bluebirds and
Tree Swallows to nest beside each other because the two species tolerate each
other's presence-- different prey base and foraging habits and such. However,
the literature also states that the two species will not tolerate members of
their own species nesting in paired boxes. Today I discovered a situation that
seems to refute that statement, at least on one instance. I have paired boxes
that are hosting 2 breeding pairs of Tree Swallows. They are not only not
aggressive toward each other, but the birds visit each other's boxes, and
joined together in divebombing me during box inspection. I have never seen this
before. Have any other box monitors witnessed this behavior in Tree Swallows?
Larry Cartwright
prowarbler@xxxxxxxxxxx
