Ducks@SBG

Lesser Whistling Duck (Dendrocygna javanica) or Wandering Whistling Duck (Dendrocygna arcuata)
Hopefully, they are Lesser Whistling Ducks, native water fowl.

Lesser Whistling Duck and Wandering Whistling Duck as both look almost the same. There are some differences as below:
Lesser: yellow eye ring, not-so prominent white plumes, no spot on breast, red uppertail coverts, lack of prominent dark crown and nape.
Wandering: no yellow eye ring, prominent white plumes, spots on breast, pale undertail coverts, prominent dark crown and nape.
From:  http://www.flickr.com/photos/lawrenceneo/sets/72157624124726639/comments/

It seems necessary to take some photos from Jurong Bird park later.