Cambridge, Mass.
1908.
July 2
  Ever since June 3rd last I have seen or heard
Black-billed Cuckoos in our garden whenever I have visited
the place. Early in the month they cooed a good deal but
towards its close they gave only the long series of notes. These
I find are uttered by both birds of the pair, which
I have had under close observation of late. Whenever one
calls the other is nearly sure to answer it in the
course of a few seconds, after which both are likely
to remain silent for from one to two minutes. Whether
or not both sexes coo I have not been able to ascertain.
During the past week I have seen both birds many
times a day flying to and from the lilacs at the rear
of our house. Here I found their nest this morning
admirably concealed in a dense mass of foliage of one
of the lilacs within six or eight feet of the back of
the smoke tree where a pair of Yellow-billed Cuckoos
nested last year. The Black bills approach their nest
from every direction sometimes streaking towards it
by short flittings through the branches, sometimes
gliding down to it from a distance on set wings
and at the last dropping directly into the mass
of foliage from above, a truly remarkable and very
interesting evolution. I often hear them very near the
nest. Indeed they give their long succession of notes
rather oftener within a few feet of it than anywhere
else. They seem to spend much of their time in
the garden but I hear them in neighboring grounds
also. Thus far I have heard from them only the
prolonged call & the cooing, never the worroo-oo cry.
Although we spend part of every evening on the back
piazza I have not once heard either bird utter any
sound after dark. The nest is out of reach & I have not
observed it closely.
Black bill Cuckoos nesting in our garden.