A bewilderment of birds

The American poet Howard Nemerov used the phrase "a bewilderment of birds". Is that a common phrase, or is it original with him?

Not common in the U.S. I've never seen it in decades of reading. ~rb

There are several sites on the Internet listing names for groups of animals, like an exaltation of larks, a murder of crows, or a crash of rhinoceroses. On none of the lists did "bewilderment of birds" appear. One could find the terms: Aviary, Brace (two game birds in hand),
Cast, Dissimulation, Fleet, Flight, Flock, Knob, Parcel, Plump, Volary, Volery, and Congregation. (Sorry for the capital letters; I'm quoting.) I may have missed some, but bewilderment seems to be a fancy of Howard Nemerov.
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