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Introduction

Our goal in creating Birds of the Sierra Nevada is to offer a beautifully illustrated and user-friendly book to everyone who is interested in Sierra birds. We hope that the book will enrich the experiences of visitors to the Sierra who want to know about the birds they see, inform Sierra residents who want a deeper understanding of the birds they observe daily, and engage the interest of serious ornithologists who want detailed, up-to-date, and well-researched information about Sierra birds.

The origins of this book date back to 1985, when Discovering Sierra Birds was published jointly by the Yosemite Natural History Association (YA) and the Sequoia Natural History Association. That book was out of print by the mid-1990s, and in 1998 the YA president, Steve Medley (to whom this book is dedicated), asked us to revise and expand on that book with broader geographical and species coverage; a stronger focus on status, distribution, and conservation of Sierra birds; and new artwork. What started as a revision of that book has evolved into an entirely new volume. This compilation and distillation of our own storehouses of bird knowledge, and those of scores of other birders and naturalists, has contributed to the species accounts and illustrations. Our hope is that this book stimulates greater interest in the birds and natural history of the Sierra and inspires some readers to work for broader protection of its remaining wild areas.

BOUNDARIES AND SUBREGIONS

Defining exact boundaries for the Sierra ultimately requires making some arbitrary choices. One could use characteristics like soil types or plant communities to define borders, but such features are not always helpful for observers on the ground. Instead, we wanted to use boundaries that were easy to understand and identify for birders and other natural historians. We also wanted to define the Sierra in a broad sense, including areas east of the crest that, although not necessarily in the heart of the range, are strongly influenced climatically and biologically by this great range.

MAP 1 Political and road map

For the purposes of this book, we define the Sierra as extending from Highway 36 (near Lake Almanor in Plumas County) in the north to Highway 58 (Kern County) in the south. The western border follows the 500-foot elevation contour except for a small portion south of Porterville, where it follows U.S. Forest Service ecological zone boundaries, rising to approximately 1,200 feet at Highway 58 (see Map 1). The eastern border is roughly defined by Highways 395 and 14 but also includes large East Side lakes, reservoirs, and wetlands that attract huge numbers of Sierra birds and that are immediately adjacent to the region (e.g., Mono Lake, Bridgeport Reservoir, Topaz Lake, Carson Valley, and Honey Lake) and the Owens Valley floor. We define the West Side as the region west of the Sierra crest down to the 500-foot contour, and the East Side as the region east of the crest roughly to Highway 395. While this definition of West Side and East Side is mostly consistent with watershed boundaries (i.e., West Side waters flow west and East Side waters flow east), a few watersheds do not follow this general rule. For example, Sierra Valley (Plumas and Sierra Counties) is within the west-flowing Feather River watershed, is east of the crest, and includes biotic communities associated with the East Side. Therefore, from a bird habitat perspective, Sierra Valley really belongs to the East Side.

The Sierra’s accessibility makes observing birds especially easy and rewarding. Public lands are plentiful, with huge pristine areas preserved in Yosemite, Sequoia and Kings Canyon National Parks, and numerous National Forest Wilderness Areas. Major all-weather highways, such as Interstate 80 and U.S. 50, transect the range, as do many state routes; other highways, such as Highway 49, run mainly north and south through the foothills. In a morning’s drive, one can traverse the West Side from California’s Central Valley nearly up to tree line at Sonora Pass on Highway 108 or Tioga Pass on Highway 120 through Yosemite National Park. A long day’s drive down Highway 395 takes one through most of the habitats characteristic of the East Side.

NOMENCLATURE, TAXONOMY, AND SUBSPECIES

We group species accounts into their respective families. The order of families and species and all common and scientific names follow the American Ornithologists’ Union’s Check-list of North American Birds (1998 [7th edition], plus all changes up to the 52nd supplement published in the Auk [2011, volume 128]). Howell et al. (2009) proposed using a standardized species order for field guides that would be more useful for identification purposes and would not change with each revision of the official Check-list. While we agree that a standardized order is appropriate for field guides, where identification is the main purpose, we think it important to use the most current taxonomic order for publications that focus on natural history. Embedded in this taxonomic sequence is our best current knowledge about the interrelationships and evolutionary history of each species. Thus taxonomic order is inherently an element of natural history and should be used in this context.

We discuss subspecies occurring in the Sierra when we have significant information about their status and distribution (such as differing winter versus summer populations), when the subspecies are identifiable in the field, or when current research suggests that a species may be split in the future. Because naming and recognition of subspecies is dynamic and sometimes controversial, we only cite subspecies that are widely accepted. We also provide a common name to identify a subspecies when that name is frequently used and widely recognized.

In the “origins of names” sections of the species accounts, we have used the following abbreviations for the derivations of common and scientific names: Anglo-Saxon (AS.), French (Fr.), Greek (Gr.), Italian (It.), Latin (L.), Old English (OE.), Old French (OF.), Old German (OG.), Old Icelandic (OI.), Old Latin (OL.), Spanish (Sp.), and Swedish (Sw.).

SPECIES INCLUDED AND ABUNDANCE CATEGORIES

One of our most challenging decisions was where to draw the line between rare species and the more common ones that required full species accounts. As we write this, 442 species have been observed at least once in the Sierra as we define the region (see Appendix 1 for the complete list). We decided to include full accounts of the most regularly occurring species and identified 276 species in 54 families that met the threshold of being abundant to uncommon as defined below. For all these species, we provide illustrations and family and species accounts. Another 166 species have been seen in the Sierra region but are considered rare, casual, or accidental visitors. Their status and distribution are described briefly in Appendix 2. In all cases, our assessment of relative abundance and seasonal status is based on a combination of our own personal experience, the experience of the many experts we consulted, and data gleaned from Christmas Bird Counts, Breeding Bird Surveys, and eBird. In recent years, both the quantity and quality of eBird data have dramatically improved, allowing us to verify anecdotal experience with quantitative data.

The approximate abundance of each species is described using the categories below. Each category is based on the relative frequency that an experienced birder might expect to see or hear a given species in its favored habitat and in the appropriate season during peak birding hours. These categories reflect the likelihood of detecting a species in a given habitat and season; it may be more or less numerous at any particular site; rare, casual, and accidental species are discussed only in Appendices 1 and 2.

ABUNDANT. Encountered on every day afield, usually many individuals.

COMMON. Encountered on most days afield, sometimes many individuals.

FAIRLY COMMON. One or a few individuals encountered on most days afield.

UNCOMMON. Encountered on relatively few days afield, never in large numbers; often missed unless a special search is made.

RARE. Seldom encountered and often highly localized; at least a few individuals occur in the region in all or most years.

CASUAL. Not encountered in the region in most years, but a pattern of occurrence may exist over many years or decades.

ACCIDENTAL. Encountered in the region on one or a few occasions (<5) and the species is far out of its normal range.

BIRD SEASONS

The lives of birds are tied intimately and inextricably to the passage of seasons, and major changes take place in Sierra bird life as the year progresses. Birds migrate, stake out territories, court, nest, molt, and shift their habitats in response to seasonal cues such as changing day length and weather patterns. Climate varies dramatically from the foothills, with their mild winters and hot, dry summers, through the wetter, cooler middle elevations, up to the vast Subalpine and Alpine zones with frigid, long winters and short summers. Birds living at different altitudes follow radically different yearly schedules, as do birds of different species. Taking such variability into account, the “bird seasons” we have used throughout the book do not follow strict calendar dates, but rather capture seasonal changes from a bird’s perspective using the standard definitions from North American Birds:

WINTER. December–February

SPRING. March–May

SUMMER. June–July

FALL. August–November

ILLUSTRATIONS

Because this book is not intended to be used as a field guide, we did not attempt to include illustrations of all plumages of every bird. Most illustrations are of adult birds, except where indicated otherwise.

BIRD FINDING THE SIERRA

Although this book is not intended as a bird-finding guide, the species accounts include many examples of when and where to find particular species in the Sierra. The first section of the bibliography includes two excellent sources for more detailed information: Kemper 1999 and Schram 2007. Joe Morlan’s “California Birding Pages” (http://fog.ccsf.cc.ca.us/jmorlan/) also includes links to information on hundreds of locations, with the very latest tips on where to find birds in California, including the Sierra. Bruce Webb moderates an electronic discussion list (http://groups.yahoo.com/group/sierra-nevadabirds/) that provides almost daily updates on Sierra bird observations, including rarities.

CITATIONS OF PUBLISHED SOURCES

Because we wanted to create a book that would appeal to a broad spectrum of readers, we decided not to include full citations within the text in every case where we include information from a published source. Instead, we provide a full bibliography of all published references we consulted while writing this book, organized by topics and family groups. In most cases, it will be clear which facts are based on which source. For natural history we relied heavily on our own experience and information published in Birds of North America, available from Cornell Laboratory of Ornithology, both in print and online through subscription (http://bna.birds.cornell.edu/bna/). Frequently consulted publications (e.g., Gaines 1992; Grinnell and Miller 1944; and Shuford and Gardali 2008) are noted in the first section of the bibliography.