copyright 2003 Shearwater Journeys

Sighting
Debi Shearwater and I were out on Monterey Bay teaching an ABA/IFO workshop. Winds were south @ 10-15 knots and skies were broken overcast. Nine participants in the workshop were on board. We were enjoying a very productive day with 10's of 1000's of gulls, fulmars, and shearwaters, mostly concentrated in an area to the southwest of Point Pinos outside of the south end of the bay.

At 1407 we were at 36 37.0 N, 122 01.4 W headed SSE. Debi and I were near the bow on the port side discussing the merits of the ABA when Debi spotted a small bird headed westward and shouted "Hey!". I got on it immediately and watched it fly toward us. It was a completely unfamiliar bird and my thoughts on its identification went rapidly from White-faced Storm-Petrel to Stejneger's Petrel to some sort of diving petrel to very small and contrasting, white-faced, black-and-white shearwater as it approached to within 40 m and flew by to the west. I noticed shallow white ovals on the sides of the rump and called "Townsend's Shearwater!," then it banked, showing completely white undertail coverts, and I switched to "Manx? Shearwater," but I wasn't happy with this and called forward for the participants on the bow to get on the bird. After it disappeared to the west I felt it was a Little Shearwater and quickly checked Harrison (1983) to confirm that undertail and facial color were indeed supposed to be white like this bird. Debi agreed that it was too small, looked nothing like a Manx, and that it reminded her of a similar bird she had previously seen in the bay which she thought was a Little. We began a search pattern and after 45 minutes of this we had essentially given up on finding it again. I was resigned to add it to my scrap heap of observations (Dark-rumped Petrel in 1988, Parkinson's Petrel, Markham's Storm-Petrel) of first-record seabirds in California waters that "got away" but for which I was confident enough to write descriptions for the record.

But at 1505 we refound it sitting with a flock of gulls and Pink- footed Shearwaters at 36 36.5 N 122 01.9 W. We then began a series of approaches, whereby the bird would flush, fly 1-500 m, and resettle, usually in the company of gulls or fulmars. We did this 5-7 times over the next 45 minutes. On at least two occasions we approached the sitting bird within 50 m. Debi took four rolls of photographs and Beverly Adams, one of the participants, obtained several minutes of digital video recordings, distant and shaky but including the bird in flight. I watched it the entire time through 10X binoculars in various angles of good light (it was mostly sunny by this time and the boat captain maneuvered the boat so that the sun was behind us or at an obtuse angle during each approach), both sitting and in flight. We last saw it flying westward at 1545 at 36 37.3 N, 122 02.0 W.

Description
This was the smallest shearwater I have ever seen. It was much (~50%) smaller in mass than the California Gulls and Northern Fulmars it sat with. At one point it sat adjacent to a Bonaparte's Gull and was roughly equal in length (see attached drawing). Its wings were very rounded which caused it to resemble a thin-winged alcid in flight almost as much as a shearwater. I noted these rounded wings on several occasions, and how different they were from the pointed wings of other black-and-white shearwaters. It flew low to the water with very rapid wing beats interspersed occasionally with irregular short glides. Although the flight was obviously that of a shearwater it was unlike Manx or any other species in the rapidness of its wing beats, indicating a heavier wing load, and the irregular rhythm as opposed to the consistent flapping then gliding of Manx and the others. Relative to other black-and-white shearwaters its bill was also very short and slight and its tail was short and seemed to be more broadly rounded. At one point it dove twice for 3-4 seconds each. The posture as it dove also resembled an alcid more than it did a shearwater.

The upperparts were black, without the slightest hint of brownish. They were blacker than those of Manx and offset very white underparts giving a very contrasting appearance (which, along with small size, gave me the impression of Townsend's Shearwater). I spent much time studying the face of the bird. The white came up from the sides of the neck in a circle above the auriculars and eye. The eye was thus located in this white area although there was the appearance of some smudging above and around the eye which was either color or an effect from the apterium between feather tracts. See drawing. The underparts were gleaming white. The white extended high along the flanks such that the sitting bird appeared equally black and white. Near the flanks the white extended slightly up to the sides of the rump forming two shallow ovals. The undertail coverts were uniformly white to the tips, as in Manx Shearwater although, unlike Manx, the covert area was broadly rounded, completely obscuring the short rectrices. In flight the underwings appeared virtually entirely white, with very little noticeable dark along the leading and trailing edges. The axillars and underwing coverts were uniformly gleaming white. See drawing for distributions of white and black.

On at least four occasions I studied the legs and feet as the bird took flight. They were a medium-pale bluish gray with black tips to the toes. I mentioned to the trip participants to check the leg/foot color and all agreed that it was grayish to bluish gray. One participant (Noel Mann) thought she detected a pinkish tinge but later attributed this to the lowering angle of the sun. There was a patch of paint on the inside lower rail of the boat near the bow which essentially matched this color and I had it photographed and video-recorded for reference.

Discussion
This bizarre little bird simply was not a Manx Shearwater, of which I have seen 100's in the Atlantic and 4-5 off California. It was way too small, had much more rounded wings, was too black above, had too much white in the face and sides, and flew differently. The bill was very small and I believe that the bluish leg color may rule out Manx. Likewise, the small size along with the black upperparts, lack of any dark coloration to the undertail coverts or underwing, and bluish legs and feet eliminates Audubon's and (to my knowledge) all other small shearwaters except Little. I have never seen a Little Shearwater but am confident that this was one due to the above-noted features. I have written the above without reference to books save the quick check of Harrison (1983) as mentioned. Tomorrow we will look at more references.

Peter Pyle
29 October 2003


Follow-up
I have now checked the sources we had on hand for the workshop that include Little Shearwater: Harrison (1983, 1987), Lindsey (1986), Enticott and Tipling (1997) and the NGS Field Guide (3rd and 4th editions). It is nice to see that the Monterey bird matches Little Shearwater in all respects, including size, shape, flight style, plumage, and leg color. The references mention the lack of banking in Little, which matches what we saw (although I neglected to state this in my description; see also the video). The bird flew low to the water and remained more-or-less horizontal, even during its flights at an angle to the 10-15 knot winds. I now believe that the smudging noted around the eye was dusky mottling (rather than apteria), as this matches several photos (see below). Otherwise I have nothing more to add to my description of the bird's appearance after viewing the references.

The Monterey bird certainly showed the characteristics of one of the white-faced subspecies as opposed to P.a. elegans of the south Atlantic and the Chatham Islands east of New Zealand. Photos that looked most like the Monterey bird include all three of adults on the ground in Lindsey (1986:311-314) and #6 on p. 89 of Enticott and Tipling(1997). It did not resemble those in the photos in Harrison (1987, 205-206, p. 69) or #5 on p. 89 of Enticott and Tipling (= the same as 206 in Harrison, reversed), where the eye is in the dark area extending down from the cap. The latter, at least, was identified as elegans by Enticott and Tipling. In addition to elegans there are 4-5 subspecies that occur in the South Pacific. None of the above references indicate how these subspecies vary but they appear to all have white faces. Those in Lindsey that resembled the Monterey bird were from Norfolk and Lord Howe Islands and thus were of the nominate (assimilis) subspecies. Regardless, the Monterey bird easily matches the characters of most Pacific populations, from one of which it undoubtedly originated.

Enticott, J. and D. Tipling. 1997. Seabirds of the world. A complete reference. Stackpole Books, Mechanicsburg PA.
Harrison, P. 1983. Seabirds. An identification guide. Christopher Helm, Kent.
     --- 1987. Seabirds of the world. A photographic guide. Christopher Helm, London.
Lindsey, T.R. 1986. The seabirds of Australia. Angus & Robertson, London.

Peter Pyle
30 October 2003

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