Four Decades of Christmas Bird Counts in the Great Plains: Ornithological Evidence of a Changing Climate

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Papers in Ornithology Papers in the Biological Sciences 2-2-2009 Four Decades of Christmas Bird Counts in the Great Plains: Ornithological Evidence of a Changing Climate Paul A. Johnsgard University of Nebraska-Lincoln, [email protected] Thomas G. Shane Garden City, KS., [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/biosciornithology Part of the Ornithology Commons Johnsgard, Paul A. and Shane, Thomas G., "Four Decades of Christmas Bird Counts in the Great Plains: Ornithological Evidence of a Changing Climate" (2009). Papers in Ornithology. 46. https://digitalcommons.unl.edu/biosciornithology/46 This Article is brought to you for free and open access by the Papers in the Biological Sciences at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Papers in Ornithology by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Four Decades of Christmas Bird Counts in the Great Plains: Ornithological Evidence of a Changing Climate Paul A. Johnsgard Foundation Professor Emeritus of Biological Sciences, School of Biological Sciences University of Nebraska–Lincoln, NE. Winter Range Maps by Thomas G. Shane Garden City, KS. University of Nebraska–Lincoln Libraries Lincoln, Nebraska 2009 Copyright © 2009 Paul A. Johnsgard & Thomas G. Shane Contents Page Foreword and Acknowledgments 1 Part 1. Introduction 3 Methods of Study 3 Topography, Landforms and Climate of the Great Plains 6 Natural Vegetation and Avifauna of the Great Plains 10 Climate Change and its Effects on Great Plains Birds 17 Part 2: The Winter Birds of the Great Plains 21 Family Anatidae: Swans, Geese and Ducks 21 Family Phasianidae: Pheasants, Grouse and Turkeys 47 Family Odontophoridae: New World Quails 53 Family Gaviidae: Loons 54 Family Podicipedidae: Grebes 56 Family Pelecanidae: Pelicans 58 Family Phalacrocoracidae: Cormorants 59 Family Ardeidae: Herons and Bitterns 60 Family Cathartidae: American Vultures 61 Family Accipitridae: Kites, Hawks and Eagles 62 Family Falconidae: Falcons 72 Family Rallidae: Rails, Gallinules and Coots 77 Family Gruidae: Cranes 79 Family Charadriidae: Plovers 80 Family Scolopacidae: Sandpipers, Snipes and Phalaropes 81 Family Laridae: Gulls and Terns 84 Family Columbidae: Pigeons and Doves 91 Family Cuculidae: Cuckoos and Roadrunners 95 Family Tytonidae: Barn Owls 96 Family Strigidae: Typical Owls 97 Family Alcedinidae: Kingfishers 104 Family Picidae: Woodpeckers 105 Family Tyrannidae: Tyrant Flycatchers 115 Family Laniidae: Shrikes 117 Family Corvidae: Jays, Magpies and Crows 118 ii Family Alaudidae: Larks 125 Family Paridae: Titmice 126 Family Sittidae: Nuthatches 131 Family Certhiidae: Creepers 134 Family Troglodytidae: Wrens 135 Family Cinclidae: Dippers 141 Family Regulidae: Kinglets 142 Family Turdidae: Thrushes and Solitaires 144 Family Mimidae: Mockingbirds, Thrashers and Catbirds 149 Family Sturnidae: Starlings 153 Family Motacillidae: Pipits 153 Family Bombycillidae: Waxwings 155 Family Parulidae: Wood Warblers 157 Family Emberizidae: Towhees, Sparrows and Longspurs 160 Family Cardinalidae: Cardinals and Grosbeaks 181 Family Icteridae: Blackbirds, Orioles and Meadowlarks 182 Family Fringillidae: Boreal Finches 190 Family Passeridae: Old World Sparrows 200 Literature Cited 201 Species Abundance Tables 221 Winter Range Maps 334 iii Foreword and Acknowledgments Foreword The rationale for this book has its origins in Terry Root’s 1988 Atlas of North American Win- tering Birds, which provided a baseline landmark for evaluating the nationwide winter distribu- tions of North American birds, using data from the National Audubon Society’s annual Christ- mas Bird Counts birds from 1962-63 through 1971-72. Tom Shane and I speculated that an up- dated 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 specula- tions 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.. Following Root’s precedent, it is appropriate to dedicate this study to the countless thousands of people who have participated in Christmas Bird Counts over the years. This is especially true in the northern Great Plains, where the weather in late December can be unbearable. The first Christmas Count one of us (PAJ) participated in was centered at Fargo, ND, in late December of 1952. The temperature was a scant seven degrees above zero, with a mercifully unknown but memorable wind-chill, and only 17 species to be seen after an entire day of effort. Upon reflec- tion, it seemed a good reason for applying to graduate schools having warmer climates. Since then, winters in North Dakota have thankfully become somewhat warmer, and the number of people participating in Christmas Bird Counts has increased greatly. Considering only the 40 winters chosen for the present analysis, from 1967-68 to 2006-07, and the multi-state region extending from North Dakota through Oklahoma plus the Texas panhandle, there have been nearly 3,000 Christmas Bird Counts and more than 40,000 participants (many of whom represent repeat paricipations in different years). In a real sense, all of these people have directly contri- buted to this book. The idea of doing a book on winter birds of the Great Plains was Shane’s. Johnsgard agreed to participate and suggested patterning the book after his earlier (1979) summary on the breeding birds of the Great Plains states. He also agreed to analyze several decades of Christmas Bird Count data, to document regional winter bird populations, and to estimate possible population trends over the past half-century. Students at the University of Nebraska’s Biological Field Sta- tion in western Nebraska were assigned the initialextraction of data on more than 200 species for this phase. Shane agreed to produce winter range maps for all the nearly 200 species well- documented by Christmas Count data. It should be pointed out that the Christmas Bird Counts, which are always performed within two weeks before or after Christmas, do not truly inventory the birds of the coldest part of a Great Plains winter, which typically occurs around the middle of January. They do, however, provide by far the largest and most long-running database available for trying to judge winter bird populations and associated population trends in North America. A nationwide analysis of Christmas Count data relative to climate change is now currently underway by the National Au- dubon Society that will cover the same forty-year period as our study, and will also incorporate data from four decades of Breeding Bird Surveys.(Weidensaul, 2007), 1 Likewise, attempting to summarize published migration data has its problems, for most such arrival and departure information is relatively old, and does not reflect recent climatic trends. For example, the migration data given for Nebraska are primarily based on an analysis of published arrival and departure dates published between 1933 and the late 1970’s (Johnsgard, 1980). Al- though these dates more closely reflect climatic conditions of the mid-1900’s than those of the present, such data provide a comparative basis for evaluating future migration information, and are the only extensive series of dates available for the Great Plains region. Records from recent years suggest that average spring arrivals now average about two weeks earlier in Nebraska, and average autumn departures are now at least 34 weeks later. These deviations from long-term av- erages appear to be more extreme to the north of Nebraska, and less divergent southwardly, in parallel with more rapid winter amelioration in higher latitudes during recent decades. Acknowledgments For helping in the tedious job of extracting and summarizing Christmas Bird Count data, Johnsgard wishes to thank numerous University of Nebraska undergraduate students studying at Cedar Point Biological Station.. They include Laura Achterberg, Eva Anguilano, Matthew Colling, Andrew Furman, Lisa Levander, Michael McGuire, Sean O’Day, Elizabeth Olson, Gwendolyn Powell, Keenan Price, Nikaela Schernikau, Tyler Seiboldt, John Sens, Justin Til- berg, Mohammed Vhora, Charles Wessel and Kristin Williams. The use of University of Ne- braska computer, library, and other University facilites at Cedar Point, as will as at Lincoln, is greatly appreciated. Additional people who provided advice or helped Johnsgard in various ways included Linda R. Brown, Mindy Goldberg, Josef Kren, Ronald Martin, Mark Orsag and Sebastian Patti. Dr. Paul Royster very kindly agreed to placing the manuscript in the University of Nebraska–Lincoln Library’s digital collections of Papers in Ornithology (archived online in the UNL institutional repository at http://digitalcommons.unl.edu/biosciornithology/). Thomas Shane would like to thank Trent Smith and Janice Urie for their support through the Comprehensive Learning Center, and to Amy Heinemann and Steve Thompson at the Teaching and Learning Center both housed at

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