Tuesday, February 16, 2010

House Finches

I wrote the following for The Natural Source, a now somewhat dated on-line resource for environmental educators (http://www3.northern.edu/natsource): "The spread of the house finch across eastern North America has been a startling ornithological event. This bird is native to the western United States, including the Black Hills, but its spread to eastern South Dakota has come from the east. In 1940, house finches were introduced to Long Island, New York and they have spread back westward ever since. The species was first observed in Aberdeen in 1985. Sightings of the species in eastern South Dakota were frequent by the early 1990's, as can be seen by the Aberdeen banding data in Table 1. The species is now abundant across the state." (1996-2004 data are in addition to the original publication.)




Year# of Birds Banded
19851
19860
19870
19880
19890
19904
199113
1992128
1993121
1994447
1995499
1996542
1993121
1994447
1995499
1996
1997
1998
1999
2000
1001
2002
2003
2004
542
110
33
267
169
162
241
101
118



Curiously, since 2006, I have  banded only four House Finches in Minnesota.  I reported to you my most recent catch, the bird above, banded yesterday (another photo taken of a bird in front of snow).  I wonder what is happening here.  Are we just "behind" the invasion wave here in Minnesota?  Has the species become less common?  Has the finch eye disease knocked them back? Are House Finches just less common here than in South Dakota?  (I do see House Finches often enough in Minnesota.)

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