Birds and Mammals
First Record of Newell’s Shearwater from the Mainland of North America
Philip Unitt, San Diego Natural History Museum,
Around 3:00 AM on 1 August 2007 Swanson was with a crew working on the stabilization of the sea bluffs along the railroad tracks at Del Mar, San Diego County, California, when he noticed a bird dive-bombing a co-worker. Suspecting the bird was attracted by the light from the headlamp on his hardhat, Swanson suggested he turn the light off. He did so, but the bird continued to dive at him. The bird suddenly flew in front of him, landed, and squawked. Once again the bird took off and continued to single the same man out of the rest of the crew. He walked toward a large metal box, and the bird once again came flying toward his head. He ducked, and the bird crashed into the box and fell to the ground. Thinking the bird was probably stunned or possibly hurt, Swanson picked it up carefully, finding it very docile, and placed it in a bed of iceplant along the cliff. Some time passed, and the bird took flight, circled for a few rounds, and came back to the same area. Swanson’s shift ended around 5:30 AM, and he left the bird in the iceplant.
The following night, still 1 August, Swanson returned to work at 9:30 PM, about 14 hours since the first encounter with the bird. At this time it was by the same metal box with which it had collided the preceding night, sitting as quietly as it had been when he left it earlier in the morning. Although the bird was not seriously injured he suspected in needed medical attention. Swanson found a box, put some soft rags in it, and picked the bird up and placed it in the box. The bird remained calm in the box throughout the night as Swanson I checked on him periodically. When his shift ended at 5:30 AM on 2 August, he took the bird home, offering it water and three pieces of soaked bread, two of which it ate. Swanson’s girlfriend Dewilla Goldate called the San Diego Wild Animal Park, which referred her to call Sea World, which in turn gave her the phone number for Project Wildlife’s care center in Carlsbad. Swanson and Goldate took the bird to this center, where volunteers identified it as a Manx Shearwater (Puffinus puffinus) and transferred it to Faulkner, Project Wildlife’s seabird specialist. On 3 August Faulkner brought the live shearwater to the San Diego Natural History Museum, where Unitt identified it as a Newell’s Shearwater (Puffinus [auricularis] newelli) on the basis of the pattern of its undertail coverts: white basally, black distally. He measured it, pulled three undertail coverts for preservation of some physical evidence, Dana McLaughlin took several photographs, and Faulkner returned the bird to her home care center.
The bird was clearly a shearwater by its general shape and slender bill with tubular nostrils. Basically black above and white below, it was small for a shearwater, weighing 383 grams when received by Project Wildlife. The plumage was in good condition, rather fresh, with no evident molt. The upperparts were entirely sooty black, the black extending a short distance below the eye. The black covered the cheeks and sides of the neck, and the line between black and white turned up abruptly to meet the forward base of the wing (Figure 1). The throat, breast, and belly were pure white. The underwing coverts were white with a sharp black leading edge and some black mottling over the patagium (Figure 2). The flanks were white except that four of the longest flank feathers were largely black (Figure 3). The anterior half of the undertail coverts was largely white, the posterior half largely black, the line between black and white making the shape of the letter U (Figure 4). Some feathers near the line of division were partly black, partly white. The three feathers preserved were one entirely white basal undertail covert, one entirely black distal undertail covert, and one along the line between black and white that was largely white on its inner web and black on its outer web. The irides were very dark brown, almost black. The bill was black. The tarsi and feet were bluish to lavender, pinker on the webs, with black outer edges on both the tarsi and lateral toes.
The pattern of the undertail coverts is the primary feature distinguishing Newell’s Shearwater from the similar Manx and Townsend’s (P. [a.] auricularis] Shearwaters (Howell et al. 1994). In the Manx the undertail coverts are entirely or almost entirely white. In the single specimen of the Manx in the San Diego Natural History Museum the longest undertail coverts are white with slight black speckling and only a few of the lateral undertail coverts have significant black, mainly on their outer webs. In Townsend’s the undertail coverts are entirely or almost entirely black. The pattern on the bird picked up at Del Mar resembled that of two specimens of Newell’s Shearwater collected on Kauai.
The wing chord of the bird from Del Mar measured 232 mm, its tail (from insertion of central rectrices to their tip) 87 mm, tarsus 45 mm, exposed culmen 33.2 mm, bill depth at base 12.2 mm, and bill width at gape 14.5 mm. The measurements for the wing, tail, tarsus, and culmen are all well within the range for Newell’s Shearwater given by King and Gould (1967) and republished by Ainley et al. (1997). The tail is too long for Townsend’s, in which the tail ranges from 71 to 83 mm (Howell et al. 1994), and Manx, in which the tail ranges from 68 to 83 mm (Howell et al. 1994, Lee and Haney 1996:appendix 2). Also, at 383 grams the bird from Del Mar was near the average for Newell’s Shearwater (381 grams, Ainley et al. 1997; 391.2 grams, King and Gould 1967). This figure is high for Townsend’s Shearwater, 10 specimens of which Jehl (1982) weighed at 290 to 358 grams. The Black-vented Shearwater (P. opisthomelas) is a common nonbreeding visitor off southern California but eliminated by its wholly black undertail coverts, shorter tail, and softer contrast between the dark underparts and pale underparts. Other small shearwaters from distant parts of the globe, namely, the Audubon’s (P. lherminieri), Little (P. assimilis), Fluttering (P. gavia), Hutton’s (P. huttoni), Yelkouan (P. yelkouan), and Balearic (P. mauretanicus) can be eliminated by their paler underparts, darker underparts, dark undertail coverts, or smaller size. Newell’s Shearwater nests only in the Hawaiian Islands, primarily on Kauai. Its pelagic range lies primarily in the Equatorial Countercurrent, between 4° and 10° N. It occurs mainly west of 130° W, but small numbers range east to 106° W, well to the east of the longitude of California (Spear et al. 1995). Only small numbers range north of Kauai, to about 25° N (Ainley et al. 1997) or about 28° N (R. H. Day pers. comm.). There are no previous records of Newell’s Shearwater for the coast of North America or as far north as the latitude of Del Mar (32.95° N).
Although a specimen to document such a remarkable occurrence would be ideal, we believe the photographs and measurements support the identification adequately. Newell’s Shearwater is formally listed as a threatened species by the U.S. Fish and Wildlife Service. Threats to it include predation by feral cats and introduced Barn Owls (Tyto alba), collision with wires and other man-made hazards, and disorientation by artificial lighting at night (Ainley et al. 1997). From 1993 to 2001, Day et al (2003) reported a decline of 61.5% on the basis of radar detections and of 72% on the basis of numbers of fledglings picked up after mishaps. Typhoon Iniki in 1992 may have killed many nestlings (Day et al. 2003).
The Manx Shearwater has occurred in the northeastern Pacific Ocean as a vagrant and possible colonist with increasing frequency since at least 1992, probably since 1975 (Kessel and Gibson 1975, Mlodinow 2004, Hamilton et al. 2007). The California Bird Records Committee had accepted 87 records through 2005 (Iliff et al. 2007). This occurrence of Newell’s Shearwater in southern California suggests that identifications of the Manx in this area, many of which “are supported by scant details” (Hamilton et al. 2007:103), need continued vigilance.
Ainley, D. G., Telfer, T. C., and Reynolds, M. H. 1997. Townsend’s and Newell’s Shearwater, in The Birds of North America (A. Poole and F. Gill, eds.), no. 297. Acad. Nat. Sci., Philadelphia.