Pine Siskin (Spinus pinus)
Song: Like many other Cardueline finches, the song of the Pine Siskin often incorporates imitations of other birds (Sibley 2009),
They sometimes sing in flight, the males circling, with rapidly fluttering wings, above the treetops while singing (Messineo 1985).
They can start singing as early as February (Messineo 1985).
Pine Siskin Wind-up Call and Song, February 12, 2011, Milwaukee County, Wisconsin. Includes mimicry of the Dark-eyed Junco "tew-tew-tew" at the very end of this brief song snippet.
Wind-up Call: A long drawn, rising, buzzy trill. It very gradually (mechanically) ascends upwards in pitch, suggesting the winding of a watch.
Messineo, D. J. 1985. The 1985 nesting of Pine Siskin, Red Crossbill and White-winged Crossbill in Chenango County, N.Y. Kingbird 35:233-237.
Sibley, David. 2009. "Vocal copying by Pine Siskins." Sibley Guides. 13 May 2009. http://www.sibleyguides.com/2009/05/vocal-copying-by-pine-siskins/ 18 Jan 2011.