Cotton Pygmy Goose Nettapus coromandelianus 棉鳧
Category I. Rare passage migrant.
IDENTIFICATION
30-38 cm. Smaller and shorter billed than Eurasian Teal with a dark crown contrasting with paler head and neck. Male in breeding plumage has black crown and dark eye, contrasting white face and neck bordered below by a dark line; upperparts dark and tinged greenish.
Oct. 2009, Michelle and Peter Wong.
Female and immature have dark crown and eye stripe, pale face and neck, yellow at base of bill and mottled chest.
Oct. 2009, Michelle and Peter Wong.
In flight plain and dark brown above apart from broad white tips to secondaries.
VOCALISATIONS
The typical calls are nasal and somewhat rhythmic.
DISTRIBUTION & HABITAT PREFERENCE
Most records have occurred at Mai Po NR, but also at other sites in the Deep Bay area on inactive fish ponds or ponds managed for wildlife. Away from the Deep Bay area one was seen in flight over East Lamma Channel on 10 May 2014.
OCCURRENCE
The first two records occurred in the 1970s: a female or eclipse male on 23 October 1974 and an adult on 31 October 1976. The next record was 30 years later in 2006, since when it has occurred in one out of two years in two well-defined approximately 4-week passage periods: in spring from 10 May to 7 June, and in autumn from 9 October to 6 November. Singles or pairs only have been reported.
Unsupported records are of one reported shot at Fanling on 25 October 1931 (Hutson 1931i) and another reported shot at Chuk Yuen in September 1969 (Chalmers 1986).
BEHAVIOUR, FORAGING & DIET
No observations.
RANGE & SYSTEMATICS
The nominate subspecies occurs throughout most of its range, including HK, which extends from Pakistan east through much of India and Bangladesh through southeast Asia to Sumatra, Java, parts of Borneo, Sulawesi, the northern Philippines and New Guinea; the remaining subspecies N.c. albipennis occurs in northeast Australia. Resident except in China where it is a summer visitor to the southern half of the country (Liu and Chen 2020) and rarely as far north as Beijing (Birding Beijing 2022), where it is apparently increasing.
CONSERVATION STATUS
IUCN: Least Concern. Population trend stable.
Birding Beijing (2022). https://birdingbeijing.com/the-status-of-the-birds-of-beijing/ (Accessed 14 May 2023).
Carboneras, C. and G. M. Kirwan (2020). Cotton Pygmy-Goose (Nettapus coromandelianus), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.copgoo1.01
Chalmers, M. L. (1986). Annotated Checklist of the Birds of Hong Kong. Hong Kong Bird Watching Society, Hong Kong
Hutson, H. P. W. (1931). Notes and comments. Ornithology. Hong Kong Naturalist 2: 320-321.
Yang, L. and Y. H. Chen (2020). The CNG Field Guide to the Birds of China (in Chinese). Hunan Science and Technology Publication House, Changsha.
