The First Record of Brewster's Brown Booby Sula leucogaster brewsteri for Japan

Abstract

Abstract. On 17th May 2009 an individual Brewster's Brown Booby Sula leucogaster brewsteri was observed and photographed, on Nakanokamishima Island, a breeding ground for six seabird species, including the related subspecies S. l. plotus. Diagnostic characteristics of the individual included a whitish head, cheeks and throat, becoming gradually pale brown on the neck. The coloration of the facial skin around the eyes was rich blue, which is characteristic of the male. The absence of dark mottles on the normally white area from the lower breast to belly, which constitute juvenile and immature stages, indicate that the individual was an adult. This is the first record of this subspecies from Japan.Key words: Brewster's Brown Booby, Brown Booby, Nakanokamishima Island, subspecies, Sula leucogaster brewsteri. ῏ῌῑῌῐ῍ ̮̮ Brewster's Brown Boobyῌ ῑῒῐΐῌ ῗῖῙῌ ̮̮ῌ Sula leucogaster brewsteri.

Piquero Pardo (Sula Leucogaster) en El Perú:

“…S. l. brewsteri ha sido registrado anteriormente a varios kilómetros de su área de distribución en algunas islas del Pacífico Central (VanderWerf et al, 2008;Pyle & Pyle, 2017) y en una oportunidad en la isla Nakanokamishima (Japón; Kohno & Mizutani, 2011) Ceyca & Mellink, 2009) y 3947 km de la isla Clipperton (Fig. 8).…”

“…Figura 8. Registros de S. l. brewsteri fuera de su área de distribución, señalado con las estrellas rosadas (VanderWerf et al, 2008;Kohno & Mizutani, 2011;Pyle & Pyle, 2017;presente trabajo). La estrella celeste indica el registro de S. l. plotus fuera de su área de distribución, en las islas de Pascua (Flores et al, 2013).…”

“…La interrogante significa el límite aún no definido entre S. l. brewsteri y S. l. etesiaca (Murphy, 1936). Mapa adaptado de Kohno & Mizutani (2011).…”

Range Expansion, Pairing Patterns, and Taxonomic Status of Brewster's Booby Sula leucogaster brewsteri

“…On Midway, J. Plissner observed a male brewsteri  female plotus pair that raised a chick in 2020, but no female brewsteri were present. At Nakanokamishima Island, Japan, one brewsteri male paired and raised offspring with a plotus female from 2012 to 2014, but a second brewsteri male was not able to attract a mate despite frequent courtship attempts with plotus females (Kohno and Mizutani 2015).…”

“…The increasing sympatry of S. l. brewsteri and S. l. plotus could result in gene flow and erosion of differentiation between these forms, if they interbreed. A few mixed brewsteri  plotus pairs have been documented (Kohno and Mizutani 2015), all involving male brewsteri, but only in locations where no female brewsteri were known to be present. On Isla San Benedicto, where interbreeding has been reported (Pitman and Ballance 2002, 1984,1998,2011,2018) 1 (1998) 1 (1984,1998,2018) 1 Morris-Pocock et al 2011), it is unclear whether any female plotus were present, and thus whether the male plotus really formed mixed pairs.…”