Wednesday, September 28, 2011

Swainson's Thrush

I banded two Swainson's Thrushes on 27 September 2011. In September 2010, I blogged about this thrush's nomenclature and systematics and, in April 2010, I wrote about identifying and aging this species. The Swainson's Thrush is "one of the most common birds of northern spruce-fir forests" (Mack and Yong 2000). Across their range, however, populations have been declining. I have banded fewer Swainson's Thrushes each of the past three years (although this trend may not be statistically significant).  In any case, ornithologists do not understand the causes of the continent-wide decline. Hypotheses include habitat destruction in both the breeding and wintering ranges and cowbird predation.

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