Of marsh harriers and other exotic species

on 29th November 2006

In an earlier post on Common Moorhen (Gallinula chloropus), it was mentioned that *Western Marsh Harriers (Circus aeruginosus) and Steppe Eagles (Aquila nipalensis) were seen above the paddy fields in Malaysia where Allan Teo was observing and photographing the moorhens.

Yong Ding Li made a pertinent comment, “Take note on the point about *Western Marsh Harrier… It is actually a very very rare migrant to South East Asia and more so for Singapore (I suspect only one recent record and even then it is probably mis-IDed many times). Instead here it is replaced by Eastern Marsh Harriers (Circus spilonotus). In the oriental region, western is only regular in the subcontinent, occuring in wetlands and plains of places like Rann of Kutch, Bharatpur where it can be rather common.

However, R. Subaraj has this to say: “To me, the birds in the photo (above) look like a young female *Western Marsh Harrier (on left) and a juvenile Steppe Eagle.

“With regards to Ding Li’s statement regarding the status of marsh harriers here, it is a little out-dated. Until 2005, he is right, as reflected in Robson’s guide. It was common in Myanmar but rare or a vagrant to Thailand and Peninsula Malaysia… no confirmed Singapore records! At the end of 2005, both Western and Eastern Marsh Harriers were reported from Changi Reclaimed Land and in the weeks to follow, several birders had visited the site and confirmed the presence of both species… with as many as 3 Westerns.

“Being a skeptic myself, I visited the area a few times during that period and personally confirmed at least three *Western Marsh Harriers, along with a few Eastern, with excellent views. Reliable collegues and visiting birders, with me or independently, concurred. Hence, the *Western Marsh Harrier does occur in Singapore as a vagrant, at least.

“It is worth monitoring our area for the next few months to see if they visit again and become a regular occurrence… or if the last season was just unusual. In the last two decades, unexpected raptors have kept turning up in Singapore. Himalayan Griffon (Gyps himalayensis) (above) and Lesser Kestrel (Falco naumanni) are two others that fall into a similar category as the *Western Marsh Harrier… birds that formerly only occurred no nearer than India and Myanmar. Other unexpected raptors that have turned up include Oriental Hobby and Jerdon’s Baza (Aviceda jerdoni)… normally sedentary species found no closer than the northern half of Malaysia, where they were considered rare.

“So what is going on! Why are these species suddenly turning up in Singapore? Perhaps it is the changing climate conditions? Or the continued deforestation and/or persecution of birds further north and south of us? Perhaps a bit of both!

“Other factors that certainly contribute are the superior optics available, the better field guides and identification books and the increased number of observers covering various parts of our nation. The digital photography age is also making a significant difference in confirming species.

“Finally, and equally significantly, the shrinking habitats available due to development means that birds have less choices if they turn up in Singapore and birders have a better chance of finding them!”

Input by Yong Ding Li and R. Subaraj; images by Allan Teo (top) and Wang Luan Keng (bottom).

*Please see HERE.

If you like this post please tap on the Like button at the left bottom of page. Any views and opinions expressed in this article are solely those of the authors/contributors, and are not endorsed by the Lee Kong Chian Natural History Museum (LKCNHM, NUS) or its affiliated institutions. Readers are encouraged to use their discretion before making any decisions or judgements based on the information presented.

YC Wee

Dr Wee played a significant role as a green advocate in Singapore through his extensive involvement in various organizations and committees: as Secretary and Chairman for the Malayan Nature Society (Singapore Branch), and with the Nature Society (Singapore) as founding President (1978-1995). He has also served in the Nature Reserve Board (1987-1989), Nature Reserves Committee (1990-1996), National Council on the Environment/Singapore Environment Council (1992-1996), Work-Group on Nature Conservation (1992) and Inter-Varsity Council on the Environment (1995-1997). He is Patron of the Singapore Gardening Society and was appointed Honorary Museum Associate of the Lee Kong Chian Natural History Museum (LKCNHM) in 2012. In 2005, Dr Wee started the Bird Ecology Study Group. With more than 6,000 entries, the website has become a valuable resource consulted by students, birdwatchers and researchers locally and internationally. The views and opinions expressed in this article are his own, and do not represent those of LKCNHM, the National University of Singapore or its affiliated institutions.

Other posts by YC Wee

3 responses

  1. If you check the earlier post on Common Moorhen, you will see that the episode was experienced in the ricefields of Malaysia.

  2. The harrier is the 1st photo is a juvenile Eastern Marsh Harrier, and the eagle is a juvenile Greater Spotted Eagle.

    Note the cheek pattern of the harrier having brown patch (liked a crescent)disconnected between the eye and the neck. THis feature is in no way indicating WEstern Marsh Harrier.

    Juvenile Eastern Marsh is variable. The buff patagium and neck collar make this one superficially alike Western female, but the clinch is the cheek pattern.

    Both Eastern and Western Marsh Harriers do hybridize in eastern Siberia where they are allopatric and hybrids may wander to our region so with the rule of possibility of course it is all possible, but this particular harrier is not a Western.

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