I am curious as to whether any one else thinks Blue Grosbeaks are definitely more common in the northeastern quadrant of Colorado than they used to be. They used to be present in this area back in the 1970s and 1980s but were noteworthy, and very local. Now I would say they are sort of expected in any decent patch of rural thicket with a few trees, especially in years we have had rain (like this one).
Like so many southern species that appear to be marching northward, Blue Grosbeak is now part of the normal scene north of I-70 and e of I-25. Not sure if this is mostly due to climate change or human activities like shelterbelt plantings, or both. According to the Nebraska and Wyoming books by Sharp et al and Faulkner, respectively, they are statewide in low numbers in NE and very local in WY (no mention of trends, per se).
Also, I am assuming the great majority of CO birds are of the western race, Passerina caerulea infusa. Do we know if any examples of the other two U.S.-occurring subspecies P. c. caerulea (eastern) or P. c. salicaria (southwestern) have been seen/collected in CO? And can these be differentiated in the field by sight and/or voice?
Comments?
Dave Leatherman
Fort Collins
Like so many southern species that appear to be marching northward, Blue Grosbeak is now part of the normal scene north of I-70 and e of I-25. Not sure if this is mostly due to climate change or human activities like shelterbelt plantings, or both. According to the Nebraska and Wyoming books by Sharp et al and Faulkner, respectively, they are statewide in low numbers in NE and very local in WY (no mention of trends, per se).
Also, I am assuming the great majority of CO birds are of the western race, Passerina caerulea infusa. Do we know if any examples of the other two U.S.-occurring subspecies P. c. caerulea (eastern) or P. c. salicaria (southwestern) have been seen/collected in CO? And can these be differentiated in the field by sight and/or voice?
Comments?
Dave Leatherman
Fort Collins
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