NOTES 
Figure 1. Partial image (part of bill, breast, and wing) of the Sandwich Tern in the 
colony of Royal Terns on Isla Rasa in 2008. 
not been previously verified in Baja California (Howell et al. 2001, Erickson et al. 
2003). The first Sandwich Tern in California was observed in an Elegant Tern colony 
in south San Diego Bay in May 1980 (Schaffner 1981). What was believed to be this 
same individual recurred at the same location during the breeding seasons of 1982, 
1985, and 1987 (Collins 1997), but there was no suggestion of successful nesting 
in any year. In May 1991 an adult was seen at Malibu Lagoon, Los Angeles County, 
and in summer 1991 and again from 1995 through 1997 what was presumed to be 
this same individual frequented the colony of Elegant Terns at Bolsa Chica, Orange 
County (Hamilton et al. 2007). In 1995, Collins (1997) documented the successful 
mating of this bird to an Elegant Tern, the pair producing a single chick. A single bird 
with “a small amount of orangish coloration along the tomium” of the bill was seen 
at North Island, San Diego, in early August 2007 (Singer and Terrill 2009). Most 
recently, one with the yellow tip of the bill apparently more extensive and diffuse than 
typical of the Sandwich Tern was at San Diego 11 May 2009 (identification under 
consideration by the California Bird Records Committee; photo at www. western 
fieldornithologists . org/ gallery) . 
The Sandwich and Elegant Terns have been considered components of a single 
superspecies (AOU 1998); on the basis of a genetic study, Efe et al. (2009) reported 
the Elegant to be nested among the subspecies of the Sandwich. They proposed that 
T. s. sandvicensis of the Old World be classified as species distinct from the New 
World taxa, consisting of two sister species, T. elegans and the present T. s. acuflavi- 
dus (including T. s. eurygnathus). So it may not be surprising that in California, and 
now in Baja California, vagrant Sandwich Terns have usually been associated with 
nesting Elegant and Royal Terns. It is likely that these observations of out-of-range 
Sandwich Terns are of birds caught up in the northwestward movement in early spring 
of Elegant and Royal Terns, which have also wintered in southern Mexico, to breed- 
ing colonies in the Gulf of California and southern California rather than following 
their usual northeasterly migration to breeding colonies in the Gulf of Mexico and 
southeastern United States. 
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