Cameron Cox’s Terns of North America: A Photographic Guide is a terrific and attractively priced identification guide that should be on the bookshelf of every serious birder. This book covers 19 tern species that, despite the book’s title, may be found north of the Mexican border and includes chapters on pelagic terns (Aleutian, Bridled and Sooty), noddies (Brown and Black), which likely are not terns and should be placed in their own subfamily under Laridae, and skimmers (Black), which are distinct from gulls and terns and thus placed in their own subfamily under Laridae. The species accounts include two vagrant terns, the White-winged and Whiskered terns. The South American Large-billed Tern did not make the cut but likely would have if the sightings of this bird on the east and west sides of Florida in the latter part of 2023 occurred prior to publication. The book also excludes species found in the ABA Area in the Hawaiian Islands region but not elsewhere in the ABA Area.

This is a photographic guide, and as a result it is not the place to go for a detailed description of molts and plumages of ABA area terns. However, the text for each species includes a brief section titled “Plumage Info,” and the spectacular photographs are accompanied by detailed commentary on the applicable plumage. The excellent introduction also includes subsections that address molts and plumages of terns and applicable terminology.

In addition to the species accounts, Terns of North America includes a couple of interesting sections dealing with difficult identifications. One is titled “Tricky Thalasseus.” This section first deals with separating the subspecies of Sandwich Tern found in Eurasia, which British authorities consider to be a separate species, from the subspecies found in North America, informally known as Cabot’s Tern. This section also discusses the two populations of the yellow-billed subspecies of the Sandwich Tern found in Central and South America, which are known as Cayenne Tern, Cayenne x Cabot’s Terns intergrades resulting from interbreeding between these two subspecies in an area in the southern Caribbean, and Cabot’s Tern x Elegant Tern hybrids

The section on separating the Eurasian Sandwich Tern from the North American Cabot’s Tern could be stronger. It states that there is only one known record of Eurasian Sandwich Tern in North America, in Massachusetts, and another “highly probable” record from Chicago, when in fact there are several additional North American records in eBird. There also could have been more information on the identification characteristics of these two subspecies, which are discussed in detail in a 2023 paper by David Sibley that likely was published too late to be considered by the author (“European” Sandwich Tern in North America,” aba.org/sibley2023). Some of these characteristics may still need to be worked out because, for example, Sibley notes that Eurasian Sandwich Terns have plain, pale gray secondaries that lack the dark bar typically found on the secondaries of North American Cabot’s Terns, while Cox does not discuss the point but includes a photograph of a Eurasian Sandwich Tern with a prominent dark bar on the secondaries.

Terns of North America also includes a ten-page section dealing with identification of several similar, medium-sized terns in the genus Sterna, consisting of Arctic, Common, Forster’s and Roseate terns. Here Cox provides detailed commentary on photographs of each of these species, emphasizing size and structural differences in addition to noting more minute differences. One example is that the black on the head of a breeding adult Arctic Tern typically extends to and just below the lower eyelid but not on the breeding adult Common Tern which always has a white lower eyelid and area below; these differences can often be seen well in the field. Most birders surely would benefit from the discussion of these often difficult-to-identify Sterna terns. Learning is further facilitated by identification quizzes that are sprinkled throughout the book.

This book is so good that one wishes it covered all the world’s terns or at least every tern in North America instead of just the species north of Mexico. As a result, there still is utility to Olsen and Larsson’s somewhat dated and less visually enjoyable Terns of Europe and North America. Regardless, this is a beautiful and informative guide and would be helpful for any birder.