Junco hyemalis

from WordNet (r) 3.0 (2006)

Junco hyemalis
    n 1: common North American junco having grey plumage and eyes
         with dark brown irises [syn: {dark-eyed junco}, {slate-
         colored junco}, {Junco hyemalis}]

from The Collaborative International Dictionary of English v.0.48

Snowbird \Snow"bird\, n. (Zool.)
   (a) An arctic finch ({Plectrophenax nivalis} syn.
       {Plectrophanes nivalis}) common, in winter, both in
       Europe and the United States, and often appearing in
       large flocks during snowstorms. It is partially white,
       but variously marked with chestnut and brown. Called also
       {snow bunting}, {snowflake}, {snowfleck}, and
       {snowflight}.
   (b) Any finch of the genus {Junco} which appears in flocks in
       winter time, especially {Junco hyemalis} in the Eastern
       United States; -- called also {blue snowbird}. See
       {Junco}.
   (c) The fieldfare. [Prov. Eng.]
       [1913 Webster]