Oklahoma Winter Bird Atlas. By Dan L. Reinking. Norman: University of Oklahoma Press, 2017. ix + 530 pp. Photos, maps, graphs, figures, tables, index. $39.95 paper.

Following five years of fieldwork and many more of data analysis and writing, the Oklahoma Winter Bird Atlas has been published. Complementing the highly acclaimed Oklahoma Breeding Bird Atlas, also by Dan Reinking, the Winter Atlas presents the results of the Oklahoma Winter Bird Project coordinated by the George M. Sutton Avian Research Center.

The methods and general findings of the project are described in the Introduction. Many highly-skilled volunteers worked long hours in sometimes difficult conditions to survey winter birds in 577 blocks distributed throughout Oklahoma. One observer quipped over email, "You couldn't pay me enough money to do this work. But I'll volunteer."

The Atlas includes accounts for each species detected during the project period, as well as for additional species for which there are recent records. Each account includes a photograph of the species in winter plumage, one or more distribution maps based on project data and (in some cases) additional lake surveys, a graph and table presenting data from Christmas Bird Counts conducted by Audubon chapters, and several sections of text. The text includes sections on Occurrence of each species in Oklahoma, Habitat, North American distribution, Oklahoma distribution (mostly from data collected during the project period), Behavior, and a short list of References relevant to each species. Inexplicably, there is a section on Appearance only for the American Goldfinch (Spinus tristis).

Each species account references several sources of data. For this reason I sometimes found it difficult to determine whether a sighting described in an account's Oklahoma distribution section originated from the block surveys, the supplementary lake surveys conducted for the project, "Special Interest Species" reports solicited during the project period, observations submitted to the Oklahoma Bird Records Committee, Christmas Bird Counts, or a combination of these sources. This information might have been presented more clearly without requiring additional pages, as most species accounts do not use the entire two pages allocated.

For each species, a line graph showing fifty years of Christmas Bird Count data is used to illustrate the long-term population trend. The axes of these graphs are unfortunately not labelled. One needs to refer to the Introduction to learn that the population index is number of birds encountered per hour. For species with large fluctuations in numbers among years, the scale of the y-axis makes it appear that no individuals were observed in years when just a few were counted. For such species, logarithmic scales would have better illustrated the patterns.

The book is generally well-edited; I found only two typographical errors in 539 pages. This volume serves as a valuable reference for the wintering birds of the central Great Plains. Academic libraries in Nebraska, Kansas, Oklahoma, and north Texas should consider acquiring this book. Ornithologists and serious birders in this region will want personal copies.

Donald Edward Winslow

Deep Fork Audubon Society, Shawnee, Oklahoma