Long-tailed Shrike’s cross bill

on 21st January 2010

An earlier post on the Long-tailed Shrike (Lanius schach) shows the adult with a cross bill, claimed to be a birth defect.

Dr Jeff Lim queried whether this condition was consistent or only momentary, “…say perhaps after preening or beak cleaning? It may not necessarily be a ‘birth defect’ since picture captures a moment in time (although as judged from the image the tip of its beak does exhibit some unusual curvature).” And according to Kennie Pan the photographer, “…the cross bill does not occur all the time…”

To resolve the controversy, Kennie provided his videos (see comments in earlier post) so that images via video grabs could be examined. As shown in all the images posted here, the bill is consistently crossed all the time the bird was in the nest brooding its chick (top left).

Hope this will, once and for all, convince everyone that the Long-tailed Shrike’s bill is permanently crossed, due to a birth defect.

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

6 Responses

  1. Hi,

    Yes, the bird’s bill is permanently crossed. However, I think that the statement “Hope this will, once and for all, convince everyone that the Long-tailed Shrike’s bill is permanently crossed, due to a birth defect.” is too definitive. Afterall, Wang Luan Keng only suggested that it is “probably a birth defect”

    Bill deformity could be due to many factors, including but not limited to “environmental contaminants, nutritional deficiencies, and disease” (, as well as injury, etc. Let’s keep our minds open.


  2. I fully agree with Gim Cheong that birdwatchers/bird groups should keep their minds open always. A closed mind will eventually end up into the dustbin of birdwatching history.

  3. Hi,

    I’m a french ringer. Since 2007, I have studied the Red Backed shrike in the Limousin’s region in FRANCE. Last year, i have the opportunity to ring a female with a “funny” beak. This bird has a malformation of the upper mandible. I try to find others examples of beak deformities on shrikes. I found one abnormal bill on Northern shrike in Quebec and your observation. Where (country) did you see this special bird ? have you seen others birds (shrikes) with abnormal beak ?
    Thanks in advance.
    Raphaël BUSSIERE

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