Figure 145. This Long-tailed Jaeger shows two—and only two—white primary shafts and an extensively whitish belly contrasting with the darker breast. Its pale head and extensive whitish flash at the base of the primaries suggest a first-fall bird, but a second-fall bird probably cannot be ruled out (see Howell 1999). It was photographed on 5 August 2001 at Cordell Bank, Marin County (Scott Hein).

 

 

 

 

 

LONG-TAILED JAEGER Stercorarius longicaudus Vieillot, 1819

Accepted: 2 (100%)	Treated in Appendix H: no
Not accepted: 0	CBRC review: 1972 records1
Not submitted/reviewed: NA	Color image: none

This jaeger has a holarctic breeding range and winters at sea, typically well south of the equator but with a recent photographic record of birds apparently wintering in the southern Gulf of California (NAB 60:288). Fall migrants occur regularly off the Pacific coast, primarily between late July and late October but occasionally into November, and generally beyond the continental shelf. Spring migrants tend to pass even farther from shore, and for this reason birders seldom encounter them.

California’s oldest Long-tailed Jaeger specimen dates back to August 1894 (Loomis 1895). The identification of jaegers during their first and second years is complex, and inherent difficulties are sometimes underappreciated—even specimens of the Parasitic Jaeger have been misidentified as the Long-tailed (Grinnell and Miller 1944). This difficulty, combined with the Long-tailed Jaeger’s rarity in California’s nearshore waters, led to its early placement on the CBRC review list. During autumn, especially in late August and early September, seagoing observers at least 20 nautical miles off the central and northern coasts routinely encounter Long-tailed Jaegers. A high estimate of at least 150 individuals was made during a 12 August 2001 trip to Cordell Bank off Marin County (AB 56:102). Southbound migrants are rarer, but still regular, off the state’s southern coast, and the species has occurred at scattered locations in the state’s interior during fall.

As indicated previously, spring migrants generally pass far enough from shore that they are seldom detected in California waters. The following spring occurrences are particularly noteworthy: an adult at the south end of San Diego Bay, San Diego County, on 11 May 1962 (Garrett and Dunn 1981); a “full-tailed adult” flying north along the Whitewater River into the Coachella Valley, Riverside County, on 23 May 1987 (Patten et al. 2003); and three storm-blown adults flying southwest over the Palo Alto Flood Control Basin, Santa Clara County, on 30 May 1990 (AB 44:493).

¹On the review list 1972–1980