The Status and Occurrence of Nazca Booby (Sula granti) in British Columbia and Canada. By Rick Toochin. Published: September 6, 2024.

 

The Nazca Booby (Sula granti) is a large seabird that has a restricted global range in the Eastern Tropical Pacific Ocean (Pitman and Jehl 1998). The main breeding colonies are located on the Galapagos Islands (Pitman et al. 1995) and on Malpelo Island off western Colombia (Lopez-Victoria and Estela 2006). There are smaller colonies on San Benedicto Island off western Mexico, Clipperton Island in the Eastern Pacific (Howell and Webb 2010), Cocos Island south of Costa Rica, La Plata Island off Ecuador, and Lobos de Afuera off northwestern Peru (Figueroa 2003).

 

The Nazca Booby is a casually occurring species in California but is increasing with 59 accepted records by the California bird Records Committee (Hamilton et al. 2007, Tietz and McCaskie 2020). The Nazca Booby is very similar in appearance to the Masked Booby (Sula dactylatra) and as a result there are 45 accepted records of birds that were not identified to exact species but are referred to as Masked/Nazca Booby by the California Bird Records Committee (Hamilton et al. 2007, Tietz and McCaskie 2020). North of California, this species is accidental with scattered records up the west coast of North America. The Nazca Booby is an accidental migrant vagrant in Oregon with 3 accepted records by the Oregon Bird Records Committee involving skin and photographed records with the first coming involving a dead bird found on a beach South of the Yaquina Bay south jetty, in Lincoln County, on September 14, 2018; the second photographed from a cruise ship well offshore of Lincoln County September 22, 2019; and a weakened bird that was found at Newport, in Lincoln County 11 September 11, 2015, and was taken to a rehabilitation center in California, where it was later released; and another bird photographed from the deck of a ship well offshore of Lincoln County on September 22, 2019 (OFO 2020, e-bird database 2021). This species is a recent addition to the Washington State list with a bird photographed and seen by many observers in the Puget Sound area from originally in Carkeek Park in Kitsap County to Alki in King County to Golden Gardens Park in King County all on September 14, 2020 (e-bird database 2021).  The Nazca Booby is an accidental migrant vagrant in Alaska with a bird photographed from the deck of a ship in the Gulf of Alaska, 21 km due east of Amatuli Island on August 30, 2017 (e-bird database 2021). In British Columbia, the Nazca Booby is an accidental migrant vagrant species that has only been recently added to the avifauna of the province with a couple of recent records from Vancouver Island. 

The Nazca Booby is illustrated in most standard North American field guides. The Nazca Booby measures 81 cm in length with a wingspan of 157 cm (Dunn and Alderfer 2017). The plumage of the adult is mostly white, with black flight feathers which included the primaries, secondaries, and rectrices (Diaz et al. 2020). Immature Nazca Booby is dark brown on the upperparts and on the throat; the remaining underparts are white (Diaz et al. 2020).

 

The Nazca Booby was split into its own species from the Masked Booby by the AOU in 2000 after Pitman and Jehl (1998) documented differences in morphology, bill color, and plumage color, along with assortative pairing and habitat selection on islands where both taxa breed.

 

The Nazca Booby closely resembles Masked Booby, but the adult Nazca has a coral-pink bill with yellower tip and not a yellow bill, as in Masked (Pitman and Jehl 1998). The tarsi is khaki to dark grayish-olive, the iris is golden-yellow to orangey, and the central rectrices often are largely silvery gray to white rather than all dark (Pitman and Jehl 1998). It is more difficult to distinguish immatures of the two species, especially juveniles, which have grayish bills in both species (Pyle 2020). Most juvenile Masked Booby have a white collar across the neck, although this may be lacking on some individuals in the colony on Clipperton Island; conversely, the nape of Nazca Booby usually is brown, con color with the back and the crown, but some juvenile Nazca Boobies do have a narrow or incomplete white collar (Roberson 1998). As boobies age, the bill gradually becomes paler, and begins to acquire the diagnostic colors of the adult (Pyle 2020). In both species, the tip of the bill brightens first (Pitman and Jehl 1998). In immature Nazca Booby, the base of the bill "becomes ivory, which is then suffused with a warm purple-rose or pinkish color before becoming a brighter coral-red or orange color in its second or third year", whereas in Masked Booby "the gray base to the bill becomes steely bluish-gray and then dull greenish-yellow before it brightens into a purer yellow color" (Roberson 1998).

 

There also are subtle morphological differences between the two species. Nazca Booby is smaller than Masked Booby, with a shorter, shallower bill, and shorter tarsus, but with longer wings and tail (Pitman and Jehl 1998).

The Nazca Booby is an accidental migrant vagrant species in British Columbia with 7 provincial records. This species was recently added to the avifauna of the province with a dead bird found by Kerry Baker at Rathtrevor Beach Provincial Park, in Parksville on Vancouver Island sometime between June 26 – July 10, 2019 (D. Cecile Pers. Comm.). A second record involved an adult bird that was photographed by Jada Cavanaugh using an iPhone from the deck of a ship northeast of Galiano Island on September 27, 2020 (D. Cecile Pers. Comm.). Given the close-proximity and date of the bird found in Washington State that same month, it is very likely that this bird is the same Nazca Booby. Unfortunately, due to the grainy quality of the pictures taken, it should be classified as a Nazca/Masked Booby. The third record was of a sub-adult bird found and photographed by Rebecca LaForge and Cpt. Hans Jessen aboard an ocean vessel 170 NM west of Brooks Peninsula from February 26-27, 2022. (D. Cecile Pers. Comm.). This record proves that pelagic birding can produce any species, at anytime of year! The fourth record was a sub-adult found and photographed by Talsi Shaw, and other observers off Victoria from whale watching boat on July 24, 2022 (D. Cecile Pers. Comm.). This bird was relocated and photographed later the same day by Orion Giles, and other observers at Race Rocks from whale watching boat on the afternoon of July 24, 2022 (D. Cecile Pers. Comm.). The same bird refound and photographed the next day by Matt Stolmeier, and other observers off Victoria from whale watching boat on July 25, 2022 (D. Cecile Pers. Comm.).  A fifth record was an adult in Queen Charlotte Sound and was found and identified by Stephen Greenwood 43 nmi west of Calvert Island while onboard the cruise ship Noordam on July 10, 2023 (D.Cecile Pers. Comm).  The bird was then observed from the same vessel by Jeffrey Pozner, this time northwest of Port Hardy on July 11, 2023 (D.Cecile Pers. Comm).  The sixth record for British Columbia involved an adult found and photographed by Josef Vavra onboard the fishing vessell FV Ocean Pearl, at coordinates (51°48'10.8"N 130°46'55.2"W) about 20km south of Haida Gwaii on October 23, 2023: (D. Cecile Pers. Comm.). The seventh record for the province was an adult found and photographed by Juan Sanchez and Ali Loewen 13 nautical miles from Quatsino Sound off the Northwest coast of Vancouver Island aboard the Coast Guard Vessel John P. Tully on July 29, 2024 (D. Cecile Pers. Comm.). 

In California, there are 59 accepted records of the Nazca Booby by the California Bird Records Committee in 2020 which have occurred in every month throughout the year (Hamilton et al. 2007, Tietz and McCaskie 2020). The highest numbers of records are for the months of July (11 records), August (13 records), September (13 records), and in October 8 (records) (Hamilton et al. 2007, Tietz and McCaskie 2020). To date all west coast records north of California, fall into these months of occurrence. It is likely that recent increases in ocean temperatures have helped push not only the Nazca Booby northward, but other species of Booby north likely in search of or following food sources. The proliferation of Booby observations since 2009 all the west coast of North America will likely continue into the near future as climate change and ocean temperature rise continues to move seabird populations in search of food and nesting sites.

1.(1) adult? 26 June – 10 July 2019: Kerry Baker (photo: dead bird on beach) Rathtrevor Beach Provincial Park, Parksville (Toochin 2002o)

2.(1) adult September 27, 2020: Jada Cavanaugh (photo) northeast of Galiano Island (Toochin 2002o)

3.(1) sub-adult February 26-27, 2022: Rebecca LaForge and Cpt. Hans Jessen (photo) 170 NM west of Brooks Peninsula (D. Cecile Pers. Comm.)

4.(1) sub-adult July 24, 2022: Talsi Shaw, mobs (photo) off Victoria from whale watching boat (D. Cecile Pers. Comm.)

         sub-adult July 24, 2022: Orion Giles, mobs (photo) at Race Rocks from whale watching boat (D. Cecile Pers. Comm.)

         sub-adult July 25, 2022: Matt Stolmeier, mobs (photo) off Victoria from whale watching boat (D. Cecile Pers. Comm.)

5.(1) adult July 10, 2023: Stephen Greenwood, mobs (photo) seen from Noordam cruise ship about 43 nmi (~79.6 km) West of Calvert Island, Queen Charlotte Sound (D. Cecile Pers. Comm.)

    (1) adult July 11, 2023: Jeffrey Pozner (photo) seen from Noordam cruise ship offshore from Port Hardy (D. Cecile Pers. Comm.)
6.(1) adult October 23, 2023: Josef Vavra (photo) FV Ocean Pearl, (51°48'10.8"N 130°46'55.2"W) about 20km south of Haida Gwaii (D. Cecile Pers. Comm.)

7.(1) adult July 29, 2024: Juan Sanchez, Ali Loewen, mobs (photo) 13 nautical miles from Quatsino Sound (D. Cecile Pers. Comm.)

I want to thank Don Cecile for editing the original manuscript. I would like to thank Kerry Baker, Jada Cavanaugh, and Rebecca LaForge for the use of their pictures for this article. All photos are used with permission of the photographer and are fully protected by copyright law. Photographs are not to be reproduced, published or retransmitted on any website without the authorization of the photographer.

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