Jon Dunn/FIELD NOTES

Royal and Elegant Terns

The Western Tanager, December 1976

Royal-and-elegant-terns

Illustration by Mary Ellen Pereya

Beginning birders often encounter problems with our closely-related southern terns, the Royal and the Elegant. Much of the confusion, however, is due to two factors: an incomplete understanding of their distribution, plus the inaccurate portrayal of their key field marks in the standard field guides.

The Elegant Tern arrives from Mexico in early March, and about a hundred pairs nest at the south end of San Diego Bay. North of the San Diego area, however, the species is very rare until late June, when post-breeding birds push up the coast from their nesting sites in the Gulf of California. These post-breeding flights vary from year to year, but during a good flight year the bird can be seen in numbers north to the San Francisco Bay area—with a few almost to the Oregon State line. The numbers of Elegants dwindle during October, and the last birds leave the California coast by early December. Mid-winter reports of the species (including those on Christmas Counts) are undoubtedly in error, as there are no properly documented winter records.

The Royal Tern, another visitor from the south, is primarily a winter resident in Southern California — and winter reports of Elegants invariably pertain to this species. From September through mid-March the birds are fairly common along the coast north to Santa Barbara, with a few to Morro Bay. But further north they are purely accidental. Though during the summer a few are regularly found in the San Diego area (one breeding record), elsewhere they are rare. Both the Royal and the Elegant are strictly confined to the coast, and neither has yet been recorded inland.

The Elegant Tern is noticeably smaller and more slender than the Royal, with a proportionately longer and thinner bill; but these marks are only truly effective when the two species are together. The best mark is the pattern of black on the head. Throughout most of the year, the Royal is essentially a white-headed bird, with only a thin band of black extending from behind the eye to the nape. The important character is that the dark eye stands out in the white face. The Elegant Tern, on the other hand, has a more extensive black patch, and it includes the eye as well as the rear portion of the crown. The illustrations in Robbins' Birds of North America are in error, as this key mark has been reversed. Although the mark applies only to birds in non-breeding plumage, except for a short period in March and early April, all the Royals (including summering individuals) are in winter plumage.

Another good mark exhibited by many of the Elegants is the pinkish sheen to the underparts 

 

Originally published Western Tanager Vol. 43 No. 4 December 1976


 

Transcribed for the Los Angeles Audubon Society (LAAS) Western Tanager "Articles from the Archives" www.laaudubon.org. July 2013 by SMC.