There are many white and gray birds, and several species live in
New York. Good possibilities are Northern Chickadee (year-round),
and Loggerhead Shrike, Blue-gray Gnatcatcher and even Northern
Mockingbird in the summer, along with the ever-popular Rock Dove
(pigeon). Also several hawks, gulls and other seabirds. In short,
we need more than white and gray to help, but if you can give us a
better description: size, color pattern, behavior and where it
hangs out, we might be able to tell you more.