University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Zea E-Books Zea E-Books 2-20-2015 Global Warming and Population Responses among Great Plains Birds Paul A. Johnsgard University of Nebraska-Lincoln, [email protected] Follow this and additional works at: http://digitalcommons.unl.edu/zeabook Part of the Behavior and Ethology Commons, Climate Commons, Environmental Indicators and Impact Assessment Commons, Environmental Monitoring Commons, Meteorology Commons, Natural Resources and Conservation Commons, Ornithology Commons, Other Earth Sciences Commons, Population Biology Commons, and the Terrestrial and Aquatic Ecology Commons Recommended Citation Johnsgard, Paul A., "Global Warming and Population Responses among Great Plains Birds" (2015). Zea E-Books. Book 26. http://digitalcommons.unl.edu/zeabook/26 This Book is brought to you for free and open access by the Zea E-Books at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Zea E-Books by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Global Warming and Population Responses among Great Plains Birds Paul A. Johnsgard This book summarizes the evidence from 47 years (1967–2014) of Audubon Christmas Bird Counts (CBC) and finds that bird pop- ulations have changed and winter ranges have shifted for many species in the Great Plains states (the Dakotas, Nebraska, Kansas, Oklahoma, and the Texas panhandle). The study builds upon Terry Root’s 1988 Atlas of North American Wintering Birds, which provided a baseline for evaluating winter distributions in the mid-20th cen- tury, using data from the National Audubon Society’s annual CBC surveys from 1962–63 through 1971–72. The present analysis in- cludes all of the 40 annual CBC surveys from the 1967–8 to the 2006–7 counts, plus the results of the most recent 2013–14 CBC, and it offers quantitative descriptions of the early winter abun- dance for 147 of the most commonly encountered regional spe- cies, illustrating their temporal changes in geographic distributions and relative abundance between 1967 and 2014. As recent win- ters have become progressively warmer, the winter distributions of many birds have moved northward, by as much as two states for some species. Birds are responding to milder winter temperatures and longer periods of ice-free water and snow-free foraging sites in the Great Plains, and the shifts in their distribution provide critical indicators of the acceleration of global warming. Paul A. Johnsgard is Foundation Professor Emeritus of Biological Sciences at the University of Nebraska–Lincoln. Cover: Black-capped Chickadee, photo by Paul A. Johnsgard. Zea Books Lincoln, Nebraska ISBN 978-1-60962-065-3 ebook (pdf) Global Warming and Population Responses among Great Plains Birds Paul A. Johnsgard Golden Eagle Global Warming and Population Responses among Great Plains Birds Paul A. Johnsgard Foundation Professor Emeritus of Biological Sciences School of Biological Sciences University of Nebraska–Lincoln Zea Books Lincoln, Nebraska 2015 Text and drawings copyright © 2015 Paul A. Johnsgard. ISBN 978-1-60962-064-6 paperback ISBN 978-1-60962-065-3 e-book Set in Calisto and Consolas types. Design and composition by Paul Royster. Zea E-Books are published by the University of Nebraska–Lincoln Libraries. Electronic (pdf) edition available online at http://digitalcommons.unl.edu/zeabook/ Print edition can be ordered from http://www.lulu.com/spotlight/unllib The University of Nebraska–Lincoln does not discriminate based on gender, age, disability, race, color, religion, marital status, veteran’s status, national or ethnic origin, or sexual orientation. Abstract Based on an analysis of 47 years (1967–2014) of Audubon Christmas Bird Counts (CBC), evidence for population changes and shifts in early winter (late December) ranges of nearly 150 species of birds in the Great Plains states is summarized, a region defined as including the Dakotas, Nebraska, Kansas, Oklahoma, and the Texas panhandle. The rationale for this study had its ori- gins in Terry Root’s 1988 Atlas of North American Wintering Birds. Root’s land- mark study provided a baseline for evaluating the nationwide winter distribu- tions of 253 North American birds in the mid-20th century, using data from the National Audubon Society’s annual CBC surveys from 1962–63 through 1971–72. A later summary (P. A. Johnsgard and Tom Shane, Four Decades of Christmas Bird Counts in the Great Plains: Ornithological Evidence of a Chang- ing Climate, 2009) provided range maps and quantitative population data (ex- pressed as the average number of birds tallied per party-hour) for all 210 spe- cies reported from the 1967–8 to the 2006–7 CBC, on a decade-to-decade basis. The present analysis includes all of the 40 annual CBC surveys from the 1967–8 to the 2006–7 counts, plus the results of the most recent 2013–14 CBC. The present summary quantitatively describes the early winter abun- dance for 147 of the most commonly encountered regional species, illustrat- ing their temporal changes in geographic distributions and relative abundance between 1967 and 2014. Over this 47-year period there has been a progressive winter warming trend regionally, and associated ecological changes, influencing the early winter regional abundance and geographic distributions of many birds. The great majority these changes have involved northward shifts in early winter distri- butions. Over this approximate half-century interval at least six species (Can- ada goose, mallard, black-capped chickadee, American goldfinch, and house finch) have shifted their areas of greatest early winter abundance two states northward, and the centers of maximum abundance of at least ten other spe- cies have shifted northward by at least one state. Milder and less stressful early winter temperatures, with associated extended periods of ice-free water and greater access to snow free foraging sites, are believed to be responsible. These recent population shifts have been most evident in the northern half of the region, where increases in mean January temperatures have been greatest. Nearly all of these population and distributional changes can be attributed to recent climate changes in the Great Plains. Approximately 500 literature cita- tions are included. Barred Owl 7 Contents Foreword and Acknowledgments 9 Part 1. Introduction 13 Methods of Study 13 Topography, Landforms and Climate of the Great Plains 15 Natural Vegetation and Avifauna of the Great Plains 17 Climate Change and its General Effects on the Great Plains 22 Climate Change and its Effects on Great Plains Birds 26 Part 2: The Winter Birds of the Great Plain 31 Family Anatidae: Swans, Geese and Duck 31 Family Phasianidae: Pheasants, Grouse and Turkeys 71 Family Odontophoridae: New World Quail 80 Family Gaviidae: Loons 83 Family Podicipedidae: Grebes 85 Family Phalacrocoracidae: Cormorants 89 Family Pelecanidae: Pelicans 91 Family Ardeidae: Bitterns and Herons 93 Family Cathartidae: American Vultures 95 Family Accipitridae: Kites, Hawks and Eagles 98 Family Rallidae: Rails, Gallinules and Coots 113 Family Gruidae: Cranes 116 Family Charadriidae: Plovers 118 Family Scolopacidae: Sandpipers, Snipes and Phalaropes 120 Family Laridae: Gulls and Terns 126 Family Columbidae: Pigeons and Doves 136 Family Cuculidae: Cuckoos and Roadrunners 142 Family Tytonidae: Barn Owls 144 Family Strigidae: Typical Owls 146 Family Alcedinidae: Kingfishers 157 8 Family Picidae: Woodpeckers 158 Family Falconidae: Falcons 174 Family Tyrannidae: Tyrant Flycatchers 181 Family Laniidae: Shrikes 184 Family Corvidae: Jays, Magpies and Crows 187 Family Alaudidae: Larks 197 Family Paridae: Titmice 199 Family Sittidae: Nuthatches 206 Family Certhiidae: Creepers 211 Family Troglodytidae: Wrens 212 Family Cinclidae: Dippers 222 Family Regulidae: Kinglets 223 Family Turdidae: Thrushes and Solitair 226 Family Mimidae: Mockingbirds, Thrashers and Catbirds 234 Family Sturnidae: Starlings 240 Family Motacillidae: Pipits 241 Family Bombycillidae: Waxwings 243 Family Calcariidae: Longspurs and Snow Buntings 246 Family Parulidae: Wood Warblers 253 Family Emberizidae: Towhees and Sparrows 258 Family Cardinalidae: Cardinals and Grosbeaks 283 Family Icteridae: Blackbirds, Orioles and Meadowlarks 285 Family Fringillidae: Boreal Finches 297 Family Passeridae: Old World Sparrows 312 References 313 Appendix: Species Abundance Tables 335 9 Foreword and Acknowledgments Foreword 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 (CBC) from 1962-63 through 1971-72. Tom Shane and I speculated that an updated anal- ysis might shed light on the possible effects of more recent climatic warm- ing 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 impor- tant 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 CBC data. Following Root’s precedent,