Olive-backed Sunbird feeding chicks and removing faecal sac

on 21st March 2017

“Spent some time observing the pair of Olive-backed Sunbirds’ (Cinnyris jugularis) daily routine of feeding their two chicks and maintaining the nest cleanliness,” recounted KC Tsang.

Chick's vent lined with yellow feathers (video grab_
Chick’s vent lined with yellow feathers (video grab)

“I noticed that the chicks did not always evacuate the faecal sac for the female to immediately collect. At times the female had to remove them from the nest. I guess if it was urgent the chick could not wait for the mother to come round. I also noticed that the male did not do all this household chore, except just feeding the chicks.

Adult female waiting for faecal sac to appear (video grab)
Adult female waiting for faecal sac to appear (video grab)

“In the first half of the video clip, the female is seen stuffing a fat spider into the chick’s gullet. In the second half the chick is seen turning around so that the cloaca (vent or anus) faces the nest opening with the female getting ready to receive the faecal sac.

“Faecal sacs are disposed some distance away from the nest to avoid giving away the location of the nest to predators.

“After evacuating the faecal sac, you can notice the expression of great relief by the chick, from it’s cloaca end.

Adult female picking up faecal sac from chick's vent (video grab)
Adult female picking up faecal sac from chick’s vent (video grab)

“Note that the vent, evenly lined with yellow feathers, expand to allow for the passage of the white faecal sac that is immediately collected by the waiting female at the nest entrance.

“The clip (below) has been slowed down to half its normal speed so as to better show in greater detail the recordings.”

Field ornithologist Wang Luan Keng has this to add: “Those are feathers that surround the cloaca. All birds have such a ring of feathers surrounding the cloaca. I am not aware of these feathers having a specific name or know of any specific function of these feathers; they probably serve a protective function. The colour of the feathers would probably correspond to the colour of the vent, and may not necessary have a specific purpose. There is no reason to highlight the cloaca with a different colour.”

K C Tsang (video and account) & Wang Luan Keng (comment)
19th March 2017

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.

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