The Collaborative International Dictionary of English v.0.48:

Blackpoll \Black"poll`\, n. [Black + poll head.] (Zool.)
   A warbler of the United States (Dendroica striata).
   [1913 Webster]

WordNet (r) 3.0 (2006):

blackpoll
    n 1: North American warbler having a black-and-white head [syn:
         blackpoll, Dendroica striate]