Friday, February 20, 2015

[Ornithology • 2015] First Investigation on the Diet of the Eastern Grass Owl Tyto longimembris During the Nesting Period in Thailand

upper: Grass Owl Tyto longimembris longimembris - Chicks in nest
photo:  Akalak Kunsorn |
lower: Different sizes of pellets and prey’s skulls of eastern grass owl.

 The eastern grass owl Tyto longimembris (นกแสกทุ่งหญ้า) was first detected in Thailand in July 2006 at Nong Lom, a grassland in open peat swamp located in the south part of Nong Bong Khai Non-hunting Area, Chiang Rai. Here, it is considered to be a rare resident. At this site, we studied the diet of eastern grass owl by analysing regurgitated pellets collected at their nests during the breeding season from December 2010 to February 2011. We collected 67 pellets from five nests and identified 33 mammal skulls. To identify prey species, DNA was extracted from skulls and was analysed based on molecular techniques. The dietary remains consisted of three murids (Muridae), with the house rat Rattus rattus the dominant species detected (16 skulls, 48.5 % occurrence), and the remainder being Asian house mouse Mus musculus (13 skulls, 39.4%) and ricefield mouse Mus caroli (4 skulls, 12.1%). 

Key words: eastern grass owl, diet, pellet, nocturnal raptor

Akalak Kunsorn, Siriwadee Chomdej, Narit Sitasuwan, Prasit Wangpakapattawong,Chatmongkon Suwannapoom and Brett K. Sandercock. 2015. First Investigation on the Diet of the Eastern Grass Owl During the Nesting Period in Thailand.  Raffles. Bull. Zool. 63: 27–32. 

Kasorndorkbua, C., Kunsorn, A. & Wongchai, C. 2008. Nesting records of eastern grass owl Tyto (capensis) longimembris in Chiang Rai, northern Thailand. BirdingASIA. 9: 91–93.