Figure 62. Short-tailed and Sooty Shearwaters present one of the most treacherous field identification challenges in North America. This difficulty led the Committee to review California’s Short-tailed records through much of the 1970s. With increased field skill and a mounting total of specimens, it became clear that this species occurs regularly along the California coast in fall and winter, so it was dropped from the review list. The identification difficulties have not gone away, however, so many individuals must remain unidentified. This Short-tailed Shearwater (note the short bill and steep forehead) was photographed in December 1987 on Monterey Bay, Monterey County (Herbert Clarke).

 

 

 

SHORT-TAILED SHEARWATER Puffinus tenuirostris (Temminck, 1835)

Accepted: 40 (100%)	Treated in Appendix H: no
Not accepted: 0	CBRC review: records from 1973 through 1978
Not submitted/reviewed: NA	Color image: none

This abundant seabird breeds mainly on islands off southern Australia and spends the austral winter (boreal summer) primarily in the North Pacific and the Bering Sea north to the Bering Strait. A 7 July 2000 specimen from the Gulf of Mexico off southwestern Florida provides the only verifiable record from the Atlantic Ocean basin (Kratter and Steadman 2003).

For many years, confusion with the very similar Sooty Shearwater confounded attempts to understand the Short-tailed’s status in the eastern Pacific Ocean. During the 1970s, after a brief period of CBRC review, the Short-tailed was recognized as being regular in late fall and winter along the California coast, particularly north of Pt. Conception in Santa Barbara County. Briggs et al. (1987) estimated the state’s variable wintering population at 5000–15,000 birds, with the greatest numbers recorded during January and February between Monterey and Humboldt Counties. Sooties are abundant in the state from spring through fall, and their great numbers during this period may mask very small numbers of nonbreeding Short-taileds. By late fall, Short-taileds may outnumber Sooties, at least in certain regions or during certain years (e.g., Briggs et al. 1987, Roberson 2002, Unitt 2004). During peak winters, Short-taileds are considered common on Monterey Bay (Roberson 2002).

Short-tailed Shearwaters occur regularly in California waters between mid October and mid March. The earliest fall record of a living bird is from Southeast Farallon Island on 23 August 1990 (Richardson et al. 2003, P. Pyle in litt.). The latest documented spring records refer to sick or dead birds found on 28 April and 2 May 1997 at Coronado, San Diego County (Unitt 2004). Two Monterey County records of carcasses washed onto the beach—2 July 1947 at Pacific Grove (MVZ 119007, skeleton) and 17 July 1978 at Moss Landing (Roberson 2002)—could involve birds that died much earlier; thus, substantiated California records are lacking for the period of 3 May–22 August.

Stallcup (1976, 1990) helped to develop methods of identifying this species at sea. More recently, McKee and Terrill (2004) reviewed the identification of this and other dark shearwaters of the northeastern Pacific Ocean.