North American Birds

VOLUME 68 NO2 2015

A Quarterly Journal of Ornithological Record Published by the American Birding Association. The mission of the journal is to provide a complete overview of the changing panorama of our continent’s birdlife.

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175 V o l u m e 6 8 ( 2 0 1 5 ) • N u m b e r 2 with scattered whitish feathers. The un- derwing area looked mostly dark or dark brown, with the axillaries and adjacent co- verts uniformly very dark brown. The long, pointed tail was dark except for the central rectrices, which were tipped white; the up- pertail coverts and undertail coverts were whitish, as was the belly. The long, rather thin bill was light gray with a pinkish man- dible and dusky tip. The eyes were dark. The feet and legs were pinkish. Discussion The plumage and soft-part colors suggest that the booby was likely in its frst plum- age cycle (Howell et al. 2014; Frontispiece): dark brown tail with white-tipped central rectrices; grayish brown head, gray-brown mottled neck, and gray- brown breast band; brownish upper- wing coverts, scapulars, and back with some pale feathers; and dark-tipped pinkish bill. Immature boobies molt their wing feathers throughout the year in waves, possibly due to limited food resources in tropical waters (Howell 2010). The bird's primaries appeared to have been molted from innermost through p8, with p9 growing and p10 worn and yet to be shed (Figure 3), which likewise strongly suggests a bird late in its frst plumage cycle. It can - not be determined from photographs whether the bird had initiated its sec- ond wave of primary molt, i.e., p1 shedding (Steve Howell, pers. comm.). The photographs and feld notes sup - port the record as referring to an im- mature white-morph Red-footed Boo- by (Sula sula). Based on the location of the observation, it would seem very likely that the Red-footed Booby was of the nominate subspecies, confned to the Atlantic, rather than one of the Pa- cifc taxa (websteri, rubripes), although distinguishing a frst-cycle bird at the level of subspecies is probably not pos- sible in the feld or from photographs. There are no known prior records of Red-footed Booby in Canada. In the United States, in the Atlantic basin, Red-footed Boo- bies are rare in southern Florida, with the majority of records from the Dry Tortugas between April and July (Stevenson and An- another species of Sulidae. Abbott obtained a series of photographs (Figures 2, 3). Soon after the ship slowed and came to stop for oceanographic work, the bird left and was not seen again. Description The bird's description is based on feld notes and photographs taken by Abbott 22 Sep- tember 2014. Based on its size and shape, bird was read- ily identifable as a member of the family Sulidae. The wings were long and appeared sharply angled when the bird was soaring. Overall, its upperparts were dark brown and underparts mottled grayish brown and whitish. The head appeared mostly grayish brown, and the breast was mottled grayish brown with a more solid gray-brown breast band. The upperwing coverts, back, and scapulars were a mottled brownish tone, r e d - f o ot e d b o o b y i n n o va S c ot i a Abstract This paper details the frst record of Red- footed Booby (Sula sula) for Canada. An immature bird was photographed during a pelagic seabird survey approximately 330 km southeast of Halifax, Nova Scotia off the Eastern Scotian Shelf on 22 September 2014. This record represents the northern- most record of the species in the western North Atlantic. The paper also summarizes previous records of the species in eastern North America. Field encounter On 22 September 2014 at 11:17 AST, 42° 17' 12" N, 61° 7' 25" W, a large seabird of the family Sulidae was observed by Sue Abbott (Figure 1). This location is about 330 km southeast of Hali- fax, Nova Scotia, about 95 km from the Scotian Shelf break. Abbott was conducting a pelagic seabird survey for Environment Canada's Canadian Wildlife Service following the Eastern Canada Seabirds at Sea protocol (Gjer- drum et al. 2012) aboard the Canadi- an Coast Guard Ship Hudson. Abbott was located on the ship's bridge on the port side, approximately 12 m above the sea surface, travelling at a speed of 22 km/hr (12 knots). Conditions for seabird observation were excellent: skies were clear to roughly 15 km; winds were from the northwest, with an average speed of 37.8 km/hr (20.4 knots); swell height averaged 3 m. Sea surface temperature in the vicin- ity of the bird was 21.3° C. The depth of water in this area is approximately 4023 m (2200 fathoms). The bird followed the ship closely for about 36 minutes, travelling a distance of about 13 km. It few over the ship's bow several times, enabling Abbott to observe it repeatedly and to photograph it from several vantage points at distances of approximately 20-40 m. Based on the bird's overall shape and dark upperparts, Abbott's frst im- pression was that it was a juvenile North- ern Gannet (Morus bassanus). However, its behavior and feld marks differed enough from those of Northern Gannet to suggest This plate (at left) from Rare Birds of North America (Howell et al. 2014) perfectly captures the proportions and plumages of Red-footed Booby vis-à-vis its conge- ners in North America, Brown Booby (two at lower right) and Masked Booby (two at upper right). Red-footed has very sleek proportions in wing, tail, and head in comparison to both Brown and Masked. The top-tier illustration third from the upper right is of a white-morph Red-footed Booby late in its frst plumage cycle, very much like the individual documented in this article. Illustrations by and © Ian Lewington. Figure 1. Location of Red-footed Booby sighting from Canadian Coast Guard Ship Hudson on 22 September 2014. Locations of fying fsh sighted on 23 and 25 September are also shown. The 200-m and 1000-m isobaths indicate the approximate location of the shelf break. Graphic by Carina Gjerdrum.

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