On 9th March 2010, Dato’ Dr Amar-Singh HSS came across a large flock of Lesser Whistling-ducks (Dendrocygna javanica) at a large ex-mining pool near Chemor in Perak, Malaysiain. This pool is popular with herons, egrets, bitterns (especially Purple Heron, Ardea purpurea), Common Moorhens (Gallinula chloropus), Little Grebes (Tachybaptus ruficollis), etc.
This was the largest flock of Lesser Whistling-Ducks Amar has ever seen in the region. Counting from composite and multiple images that he took, he estimates that there were at least 19 in the flock, possibly as high as 25.
Could they be migrants gathering there after their return from the north? After all, Amar was at the same area about a year and a half ago but did not see such a large flock. Or could they be residents?
The ducks were nervous and on two occasions the entire flock made their characteristic whistle… HERE. The cries were recorded with a Nikon D90 and as the flock was in the center of the pool, the recording tends to be a bit soft. The call appears to be made when the ducks were agitated, as well as in flight.
Gretchen
Just want to say I appreciate your including (attached) sound files – also an important part of the behavior!