Eastern Grass Owl Tyto longimembris 草鴞
Category I. Rare winter visitor and spring migrant.
IDENTIFICATION
Jan. 2021, KWOK Tsz Ki.
32-38 cm. A medium-large owl with a heart-shaped facial disc, dark brown eyes, unstreaked underparts and very long pinkish-white legs that are unfeathered on the lower half of tarsus and hang well behind the tail in flight. The crown is blackish, the facial disc grey-buff with a black border, the upperparts dark brown with golden-buff markings and whitish speckles, the uppertail buff with blackish bars, the breast and neck-sides buff with little or no streaking, and the belly and vent whitish. Bill pinkish-white.
VOCALISATIONS
Has a variety of calls including a cricket-like chirruping.
DISTRIBUTION & HABITAT PREFERENCE
Recorded from grassy hillsides, reedbeds, a small grassy island and an airfield.
OCCURRENCE
There are five records of single birds in the periods 12 December to 25 January and 23-26 April.
1981: one found dead on the runway at the former Kai Tak airport on 25 December.
1991: one found entangled in kite strings on Ma On Shan on 12 December 1991 and released unharmed.
1994: one at Mai Po NR from 23 to 26 April.
1997: one at Mai Po NR on 25 January.
2020: one flushed from a grassy hillside near Heung Yuen Wai on 19 December.
BEHAVIOUR, FORAGING & DIET
The few observations include one seen approaching in low, silent flight before landing on a small grassy island at Mai Po NR after dusk and one which glided down a hillside after being flushed from a daytime roost.
RANGE & SYSTEMATICS
Widely but patchily distributed in parts of India and from Assam south to Indochina and east to southeast China including Taiwan, the Philippines, Sulawesi, Flores, New Guinea, New Caledonia, Fiji and Australia; mainly sedentary with some post-breeding dispersal of juveniles (Holt et al. 1999, Konig & Weick 2008). Five subspecies are recognised, including T. l. chinensis in southeast China and Vietnam and T. l. pithecops in Taiwan (Konig & Weick 2008). Historically in Guangdong, it was regarded as a fairly common winter visitor near Guangzhou (Mell 1922).
CONSERVATION STATUS
IUCN: Least Concern. Population trend decreasing.
Holt, D. W., R. Berkley, C. Deppe, P. L. Enríquez Rocha, J. L. Petersen, J. L. Rangel Salazar, K. P. Segars, and K. L. Wood (1999). Species accounts of Eastern Grass-owl Tyto longimembris. p. 74-75 in del Hoyo, J., Elliot, A. and Sargatal, J. Handbook of the Birds of the World, vol. 5: Barn-owls to Hummingbirds. Lynx Edicions, Barcelona, Spain.
Konig, C. and F. Weick (2008). Owls of the World (2nd ed). Christopher Helm, London.
Mell, R. (1922). Beitrage zur Fauna sinica. Archiv fur Naturgeschtichte 88 (10): 1-100. [In German].
