American Crossbill
Their flight is swift and undulating. While feeding and moving about they are quite noisy, almost constantly uttering a plaintive wheep or cheeping note. Their song is low, soft, and sweet, much like that of the American Goldfinch. 527. Acanthis hornemannii (Holb.). GREENLAND REDPOLL.-Similar to the next, but "larger (length about 5.50-6.50), with proportionally thicker and less acute bill. 8 W., 3.37; T., 2.75; exposed culmen, 35; depth of B. at base, 31."