Red-footed Booby Sula sula 紅腳鰹鳥
Category I. Accidental in sea areas especially after the passage of tropical storms.
IDENTIFICATION
Jun. 2010, Michelle and Peter Wong. Immature.
69-79 cm. The smallest booby, relatively slim-bodied and long-winged with rather long tail. Adults are polymorphic, varying from white with dark flight feathers with or without black tail to nearly all brown. Juveniles of all morphs are similar in being brown with pale belly and darker chest stripe. Most records are of immatures (illustrated), which have pale mottled grey-brown head, pale chest and belly with varying amounts of brownish (less with age), brownish upperparts, reddish feet and largely pink bill. Bare parts are paler version of adult.
VOCALISATIONS
Rarely calls away from the breeding areas and unlikely to be heard in HK.
DISTRIBUTION & HABITAT PREFERENCE
Most records have occurred in sea areas, but occasionally occurs in inshore waters or, in the case of exhausted birds, inland sites such as Discovery Bay and Mount Nicholson.
OCCURRENCE
The first record occurred in Victoria Harbour on 9 August 1996 (Lee 1998). Since then, it has occurred approximately once every two years from 3 May to 17 October, often in association with the passage of tropical storms. Rarely seen on more than one day.
BEHAVIOUR, FORAGING & DIET
More likely than Brown Booby to occur exhausted in the wake of tropical storms.
RANGE & SYSTEMATICS
Breeds in tropical and subtropical islands in the Indian, Pacific and western Atlantic Oceans; disperses widely (Schreiber et al. 2020). In China occurs in the South China Sea as far north as Taiwan (Liu and Chen 2020).
Three subspecies are recognised of which the most likely to occur is S. s. rubripes, which breeds in tropical areas of the Indian and Pacific Oceans.
CONSERVATION STATUS
IUCN: Least Concern. Population trend decreasing.
Liu, Y. and Y. H. Chen (eds) (2020). The CNG Field Guide to the Birds of China (in Chinese). Hunan Science and Technology Publication House, Changsha.
Lee, K. S. (1998). Red-footed Booby in Victoria Harbour: the first Hong Kong record. Hong Kong Bird Report 1996: 116-117
Schreiber, E. A., R. W. Schreiber, and G. A. Schenk (2020). Red-footed Booby (Sula sula), version 1.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.refboo.01.
