Barbets and cavity excavating

on 9th November 2008

Barbets are primary cavity nesters, or most of them are. They thus nest in freshly excavated cavities that they dig from rotting tree trunks and branches. This is one of a few groups of birds that are able to excavate their own cavities. Such capability is rather surprising, considering the large, usually sharply pointed bill that do not appear to be adapted for such an activity.

For roosting, some species excavate their own cavities. Others use cavities abandoned by other birds. Some even take over cavities being excavated or actively evict nesting or roosting occupants.

When actively excavating a cavity, as in the case of the Green-eared Barbet (Megalaima faiostrica) above, the tail of the bird is appressing to the bark, just like woodpeckers when probing tree trunks for insects. The entrance is usually just large enough to fit the body of the bird. This gives it an advantage when defending its cavity from intruders.

When excavating, wood chips are usually carried away, so as not to make the nest location conspicuous to predators. Red-faced Barbet (Lybius rubrifacies) has been known to even swallow the chips and regurgitate them away from the nest. Nest excavation can take from a few days to 30 days or more. Both sexes, as far as is known, help in the excavation.

Usually, barbets do not reuse the nesting cavity after the chicks have fledged, thus providing cavities for use by non-excavating cavity nesters like parrots, kingfishers, owls, etc.

Input and image by Dr Eric Tan.

This post is a cooperative effort between and BESG to bring the study of bird behaviour through photography to a wider audience

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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