Figure 168. Although White-winged Terns are recorded almost annually in North America, they remain exceedingly rare in the West. California’s first record was furnished by this widely seen adult, photographed on 26 June 1996 at Arcata Marsh in Humboldt County (1996-085; Ron LeValley).

 

Figures 167 (above), 169 (below). California’s second White-winged Tern was a second-fall bird present 4 September–16 October 1999 at Moss Landing, Monterey County (1999-142). This bird, which was appreciated by hundreds of observers, was photographed on 7 September (John Sorensen) and sketched on 13 September (Daniel Lane). Clean white sides to the White-winged Tern’s breast help to distinguish this species from a Black Tern of similar age.

 

 

 

 

 

 

 

 

WHITE-WINGED TERN Chlidonias leucopterus (Temminck, 1815)

Accepted: 2 (100%)	Treated in Appendix H: no
Not accepted: 0	CBRC review: all records
Not submitted/reviewed: 0	Color image: none

This primarily freshwater tern breeds across much of Eurasia, east to Siberia, Manchuria, and Sakhalin. As summarized by Campbell (2000a, the source of all unattributed information presented here on vagrancy outside of California), these birds migrate long distances to wintering grounds that reach from tropical Africa across southern Eurasia to Australia and New Zealand. The species has been recorded five times in Alaska between 19 May and 24 August (e.g., AB 58:584) and more than 35 times east of the Rocky Mts.

Despite this species’ extensive range, highly migratory ways, and numerous previous appearances in the New World, many observers expressed surprise when an adult White-winged Tern in full alternate plumage showed up in Arcata, Humboldt County, 20–26 June 1996 (Figure 168). Where such a popular and conspicuous bird disappeared to for the next two months is anyone’s guess, but presumably the same individual reappeared there between 27 and 30 August 1996. This record comports with the White-winged Tern’s pattern of spring and summer vagrancy across North America, where almost all records fall between early May and mid September, peaking in July. By contrast, a second-fall bird at Moss Landing in Monterey County (Figures 167, 169) was not found until 4 September 1999, and it remained through 16 October, providing the continent’s latest record.

Identification of adults in alternate plumage is straightforward. See Alström (1989), Olsen and Larsson (1995), and Campbell (2000b) for guidance on identifying birds in other plumages. Cross-breeding with the Black Tern has been documented (more than once), so North American observers should be alert to the possibility of hybrids.