Ornithology is one field of science where amateurs have made significant contributions. Birders throughout the world participate in Christmas bird counts, conduct breeding bird surveys, and report their daily sightings in various ways, increasingly via the internet. Yet the task of teasing out scientifically significant results from data collected in often quite unscientific ways is decidedly nontrivial. Nearly every state in the country has a Bird Records Committee, whose job (at a minimum) is to keep an official bird list for the state and to give peer review to reports of extralimital sightings submitted by birders, whether amateurs or professionals. One goal is thus to produce scientifically valid data about the status and distribution of bird species.
The California Bird Records Committee (CBRC) was the first of these committees in the United States, formed in 1970 and modeled after the British Birds Rarities Committee. Since then, this committee has regularly reviewed reports of California rare birds and published its findings in the journal Western Birds. These (mostly) annual articles provide not only ongoing, centralized information about these sightings, but in some individual cases also provide a context, such as patterns of occurrence and tips for separating difficult-to-distinguish species. By the early 1990s, though, members of the CBRC felt that there was the need for a larger work that would effectively summarize the Committee's findings over a longer time span and serve as a reference for those interested in the status of California's rarities.
The book Rare Birds of California is the result of this summarizing work by the CBRC. Edited by Robert A. Hamilton, Michael A. Patten, and Richard A. Ericson, this book is the joint work of a host of experienced and knowledgeable authors, editors, and reviewers. Its release in 2007 was eagerly awaited by members of the California birding community, who had long felt the need for such a reference book.
It is fair to say that this opus far exceeds those expectations. Not only is the coverage of individual species complete and carefully detailed, but the rest of the book is also rich with valuable information that enhances one's understanding of California birds and birding.
After a brief introduction to the CBRC and to the book, there are several tables listing the meetings and membership of the CBRC, the official California bird lists as of 25 June 2007 (including the Main List, the so-called "Supplemental List" of birds of certain identity but uncertain natural origin, and a list of naturalized bird species not yet fully established in California), the annual additions of native species to the main list from 1900 to 2006, and an analysis of the source regions for those added species. I found these last two tables to be unexpected and particularly welcome. I learned from the last table, for instance, that eastern North American species accounted for the largest pool of additions to the California list through the 1960s, but that in the past four decades, the largest source has been from Asiatic and arctic regions, with a significant contribution from pelagic species. The table of additions to the main list I found mesmerizing. Many of the early species added, such as the first three—Harris's Sparrow (Zonotrichia querula) in 1900, the Eastern Phoebe (Sayornis phoebe) in 1901, and Flesh-footed Shearwater (Puffinus carneipes) in 1903—are now recognized to be a regular part of California's avifauna and no longer appear on the review list. Yet the fourth species, the Black Rosy-Finch (Leucosticte atrata) in 1904, did not appear again until 1968, and as of 2003, there were only 12 accepted records. No species were added during the World War II years of 1940–1944, but since then, there has been only one year (1957) in which no birds were added. It is readily apparent from this table that the 1960s, when 48 species were added (culminating with an astounding total of 10 in 1969), were a very exciting time to be birding California. And although the rate of increase has slowed since then, as would be expected with fewer and fewer possibilities remaining for additions to the state list, there have still been some exceptional years, such as 1984 and 1998, when this list grew by eight and five species, respectively.
Included also in this first part of the book are three well-written and thoughtful essays. The first, "Trends in the California bird list: Jehl (1980) revisited," is a narrative describing trends in the California bird list over the years and speculating on species likely to be added in the future. I noted that already four of these species mentioned—the Wood Sandpiper (Tringa glareola), Townsend's Shearwater (Puffinus auricularis), Swallow-tailed Kite (Elanoides forficatus), and Eurasian Kestrel (Falco tinnunculus)—have been added to the California list since the book's publication. I also learned that in a six-week period in the fall of 1988, three Siberian species—the Terek Sandpiper (Xenus cinereus), Long-toed Stint (Calidris subminuta), and Gray Wagtail (Motacilla cinerea)—were recorded within 12 miles of one another along the central coast, and, most remarkably, these remain to this day the only records of each of those three species in the state.
The second essay, "Birding in California, 1960–2007," describes the evolving California birding community, from the so-called "golden age" of the 1960s through the present day, with an emphasis on the increasing understanding of the status and distribution of California's avifauna, knowledge and understanding of patterns of vagrancy, changes to the CBRC review list, and important sources of information on California birds made available during this time. The third essay is straightforwardly entitled "Documenting and reporting records," and it gives excellent advice to those who wish to submit records for the CBRC's consideration (or, indeed, to any bird record committee), as well as an impassioned discussion of the need for scientifically reliable information.
The bulk of the book (408 pages, including an introductory section) consists of the 240 species accounts through 2003. Included in this list are two current subspecies (Bewick's Swan [Cygnus columbianus bewickii] and the Common or Eurasian Teal [Anas crecca crecca]), two species pairs (Galapagos Petrel [Pterodroma phaeopygia]–Hawaiian Petrel [Pterodroma sandwichensis], and Masked Booby [Sula dactylatra]–Nazca Booby [Sula granti], the latter listed in addition to Masked Booby by itself), and one hybrid (Blue-winged [Vermivora pinus] × Golden-winged Warbler [V. chrysoptera]). The Main List notes only 181 species on the state review list as of 25 June 2007; as the introductory material to this section explains, there are accounts of all species that were ever under review by the CBRC, however briefly. This includes species such as the Ovenbird (Seiurus aurocapilla), which was reviewed only in 1972, with a total of three records from that year (the text notes "roughly 900" records in all).
Each such account includes summary statistics; a detailed list of all accepted records including dates, locations, age and sex (if known), notes on documentation, and the CBRC record number and report where the record was published; all rejected records; all records in circulation; all records from published sources that were not submitted for CBRC review; and a narrative. These narratives describe the global range and vagrancy of the species, discuss the pattern of occurrence within California, and sometimes include additional information, such as notes on subspecies or possible hybrids. So-called "invasion" years by particular species are noted, such as Cassin's Sparrow (Aimophila cassinii) appearing in ephemeral grasslands in the far eastern deserts in the springs after two particularly wet winters. The difficulties of handling records of birds that are kept in captivity, such as certain waterfowl, Harris's Hawk (Parabuteo unicinctus), and the Painted Bunting (Passerina ciris), are discussed, as are the challenges of separating a few especially thorny species groupings, such as separating the Iceland Gull (Larus glaucoides) from the kumlieni subspecies of Thayer's Gulls (Larus thayeri) and from various possible hybrids. For the most part, though, the narratives do not focus on identification issues (with the noticeable exception of a table summarizing the Jehl scale for assessing the intermediacy of Black [Haematopus bachmani] and American Oystercatchers [H. palliatus]). Instead, the extensively annotated text refers the reader to identification articles published elsewhere.
Most accounts are accompanied by one or more figures including black-and-white sketches or photographs, geographical distribution of records within the state, as indicated by circles of various sizes at those locations, or histograms of records by month or by year. The amount of information on each species varies, but there is much here that even experienced California birders will find new or surprising. For instance, I learned that the first state record of Brown Booby (Sula leucogaster) was of a bird "clubbed over the head with an oar (!) on 20 September 1946 at Imperial Dam," that the number of state records of Golden-winged Warbler have not decreased even while that species is in decline, and that California's first Common Grackle (Quiscalus quiscula) was a specimen collected in 1967 and misidentified as a Brewer's Blackbird (Euphagus cyanocephalus), with the error corrected in 1975, after the state's second record of that species.
There are also accounts for those species (six in all) on the Supplemental List, as well as those of hypothetical occurrence (identification not established) or questionable origin (presumed escapees). An extensive bibliography with well over 1000 references follows, after which are eight appendices, including CBRC bylaws, reports of the CBRC, abbreviations for counties and for institutions holding specimens, a master list of nearly 2000 contributors, and a collection of maps that includes counties and roads, physical relief, bathymetry, nearest point of land contours, geographical distribution of all CBRC records, and political division maps of North America and northeastern Asia. These maps are augmented inside the front and back covers of the book by lists of all bird record localities by name and by two maps locating those sites (representing southern and northern California, respectively). Two of the appendices merit special mention. One is a gazetteer of all records through 2003, by county, with the latitude and longitude of each location as well as the number of accepted records and total reports. (By far the largest number of records is from Southeast Farallon Island, with 409 accepted records, more than double any other location.) The other is Appendix H, containing noteworthy records from 2004 through 2006, including seven species that were added to the Main List during that time, as well as others that were notable for their rarity (either statewide or locally) or unusual numbers.
The book is richly illustrated, not only with the many black-and-white sketches and photographs that accompany the species accounts, but also by 72 pages of color sketches and photographs. The choice and quality of these images are both outstanding, and their presence adds considerable texture to the species accounts that comprise most of the book. I found myself greatly impressed by the artistic skill of those who supplied the sketches and by the ability of photographers to capture images that could potentially identify birds down to the individual, not just the species.
In sum, this book superbly and extensively documents and discusses the records of California's rare birds through the year 2003, as determined by the CBRC. Although a reference of this sort could be dull to read, the writing here is lively and interesting. The essays, photographs, tables, and other figures nicely complement the narrative, and the information about the CBRC makes the book feel complete. Rare Birds of California is a book that should be as essential to the California birder with any interest in rarities as field guides and other identification tools—one that will be opened on a continuing basis as readers mine more of its treasures. This modestly priced book belongs in libraries used by recreational birders and scholars alike, and will likely prove to be an important reference for research on patterns of vagrancy in North American avifauna. In that vein, this work might serve to stimulate similar efforts in other states or regions of North America, which could help further our understanding of continent-wide vagrancy patterns. My only concern is that this book necessarily is frozen in time; I hope that the CBRC will endeavor, at the very least, to put all accepted records into accessible digital form that can be updated as the Committee continues to review records.—ALEXANDER E. KOONCE, Department of Mathematics, University of Redlands, Redlands, CA 92373. E-mail: sandy_koonce@redlands.edu
