BIRDS OF THE ST. CROIX RIVER VALLEY 



165 



PINE SISKIN 



1 1 1 1 T 1 1 1 r 



1970 1971 1972 1973 1974 1975 1976 1977 1978 



YEAR 



Fig. 6. Patterns of winter abundance of common redpolls and pine siskins in the St. 

 Croix River Valley (data from Christmas Bird Counts). 



grown with various weeds, highway rights-of-way, and mixed decid- 

 uous-coniferous forest in northern regions. 



Pine Siskin {Carduelis pinus) 



Status: Regular migrant, nesting species, and winter resident. 



Migration: Fairly common (occasionally abundant) migrant throughout the 

 Valley. Fall migrants arrive in the Central Plain and Western Upland 15- 25 

 September. Peak fall migration occurs 10-30 October and departure by 

 15 November. The number of fall migrants is highly dependent on the inten- 

 sity of the migration during a given year. Typical of other winter finches, 

 peak movements usually occur during invasion years. Migrants have 

 usually departed the Northern Highland by 1 January, except during years 

 of very high populations when large numbers winter throughout the Valley. 



