Paddyfield Warbler Acrocephalus agricola 稻田葦鶯
Category I. Very rare winter visitor.
IDENTIFICATION
Dec. 2015, Paul Leader.
12-14 cm. Long whitish supercilium with narrow dark line above, though this is not as conspicuous as it is on Black-browed and Manchurian Reed Warblers. Upperparts are rich rufous when fresh but pale sandy brown when worn, while underparts vary from buff on breast and flanks to white on worn birds. Lower mandible always has dark near tip. Bill relatively small and fine. Short primary projection beyond tertials and rather short-winged and long-tailed appearance (Kennerley and Leader 1992).
VOCALISATIONS
A short, slightly nasal ‘zert’ and a ‘chak’ call can be heard in this recording.
Also gives a short buzzing call lacking in modulation.
The song employs substantial mimicry and has fewer churrs, rattles and other non-musical notes than Black-browed Reed Warbler. It is also slightly more hurried and forceful than the latter.
DISTRIBUTION & HABITAT PREFERENCE
All records have occurred in reed marsh in the Deep Bay area.
OCCURRENCE
One of the rarest of the reed warblers in HK, it occurs in less than one in three winter periods. The first was on 1 January 1991 (Kennerley 1992). Extreme dates are 18 September and 28 April, though the peak period of occurrence is from November to February. Most birds have been trapped in reed marsh at Mai Po NR. Several individuals have been trapped more than once indicating some site-fidelity, including one trapped on 6 October 2006 that was re-trapped on 3 March 2007.
BEHAVIOUR, FORAGING & DIET
Rather skulking, though occasionally recorded in song, even midwinter.
RANGE & SYSTEMATICS
Two subspecies are recognised, with that occurring in HK presumed to be the nominate, which breeds from Kazakhstan and northeast Iran east through central Asia to Mongolia and northwest China. A. a. septimus breeds from east Europe east to Ukraine and west Kazakhstan. Winters in north and southwest India, and the Himalayan foothills east to north Myanmar (Dyrcz 2020, Liu and Chen 2020).
CONSERVATION STATUS
IUCN: Least Concern. Population trend decreasing.
Dyrcz, A. (2020). Paddyfield Warbler (Acrocephalus agricola), 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.padwar1.01.
Kennerley, P. R. (1992). Paddyfield Warbler at Mai Po: the first record for Hong Kong. Hong Kong Bird Report 1991: 123-126.
Kennerley, P. R. and P. J. Leader (1992). The identification, status and distribution of small Acrocephalus warblers in eastern China. Hong Kong Bird Report 1991: 143-187.
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.
