Date of this Version
The rationale for this book has its origins in Terry Root’s 1988 Atlas of North American Wintering Birds, which provided a baseline landmark for evaluating the nationwide winter distributions of North American birds, using data from the National Audubon Society’s annual Christmas Bird Counts birds from 1962-63 through 1971-72. Tom Shane and I speculated that an updated analysis might shed light on the possible effects of more recent climatic warming trends on bird migration and wintering patterns in the Great Plains, a region known for its severe winters and also one of our continent’s important migratory pathways and wintering regions. As life-long residents of the Great Plains, we have both lived long enough to have witnessed some of these changes in avian migrations and wintering patterns personally. Johnsgard tested these speculations by doing some sample species analyses during the spring of 2008, after which it appeared that a complete survey of Great Plains winter birds would be worthwhile, based on Christmas Bird Count data.
Since the 1970’s there have been marked changes in avian habitats and regional winter climate patterns, and substantial changes in at least some Great Plains winter bird distributions and populations. In light of these changes it was decided that a survey of Great Plains winter bird populations over the past four decades might prove interesting, using Christmas Bird Count data mostly accrued since the time of Root’s landmark study, but using her results as a basis for temporal comparisons.
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