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.
Ecological Zones and Bird Habitats
The Sierra offers an extraordinary variety of bird habitats, from the rolling foothill grasslands, through oak studded savannas and giant conifer forests, up to alpine meadows and chilly, windswept peaks, and over the crest to the lakes, forests, and sagebrush flats of the East Side as well as Joshua tree woodlands of the southern desert regions. No wonder Sierra bird life is so varied! The West Side boasts an elevation gradient unequaled in the 48 contiguous states, spanning nearly 14,000 feet from the lowest foothills to the highest peaks (see Map 2). Most
