posted in: Morphology-Develop. | 0

“White-breasted Waterhens (Amaurornis phoenicurus) frequently help themselves to the aquatic snails in my water lily tubs. This common member of the rail family is supposed to breed almost all the year round. I have watched many broods grow from babyhood to adulthood in my garden. Quite a number of last-year’s babies still hang around to sneak quick snacks when the dominant pair are not watching. Following is a photographic record of the transition from black fluffballs to formally-dressed fowls.

“When the parents first bring out the chicks they are totally black (below left).

“They have a habit of tripping over their own toes (above right).

“Within a few weeks, patches of white start to show on their undersides (below left).

“The white spreads, and the typical Waterhen pattern becomes obvious (above right).

“However, their upper parts are not dark, charcoal grey, like those of the adult birds. Sub-adults are sooty, ash grey, like the one in this photograph (below left).

“By the time six months have passed, the chicks would have taken on full adult colours. But I can always tell the youngsters from the older ones. This bird, one of last year’s brood, is slim. And the demarcation between the light and dark areas is not straight and sharp (above right).

“In contrast, look at this mother behind her chick. The lines demarcating the light and dark areas of her plumage are distinct. And even though she is drawn up to her full height, she is visibly more substantial than the youngster in the preceding picture (below left).

“Adult birds are noticeably more portly than the youngsters (above right).

“There is some discussion as to how many sub-species of White-breasted Waterhens are found in Singapore. I think that those people who try to split them up into three sub-species are splitting hairs. Differences in size and stoutness are very noticeable even among individuals from the same brood. Using such differences to distinguish between sub-species cannot be credible.”

Lee Chiu San
25th March 2014

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.