hgeorge

From Nov 08 to Aug 09, 10 bird flocks were recorded and marked during the surveys.
2 were large size.
4 were median size
4 were small size.

Species composition is as follows:
Only 2 were recorded as mixed species flock. One was on Dec 2008, Lttle Swift accompanied with Asian House Martin (median sixe). Another was on Aug 2009, Little Swift accompanied with Barn Swallow (large size).
8 were single species flock; 5 were Japanese White-eye during Nov 2008, Feb&Mar 2009, large flock occurred on Mar 2009. Another 3 were Chinese Bulbul and Red-whiskered Bulbul.

Bird flocks were mainly recorded during migrant season at Tai Mo Shan summit.

wcaptain

Comments:

(1) Any definition of "large, median and small" flock size.

(2) Little Swift and barn Swallow are highly movable species. Any measures to avoid over-counting?

hgeorge

Thanks again for your comments.
1. Details of definition of ‘bird flocks’ can be found in survey manual.
http://www.hkbws.org.hk/BBS/view ... &extra=page%3D1
The definition of ‘bird flock’ is drawn from the discussion within our survey committee.
2. I agree. By method of estimation and experience of counting highly movable species.