Javan Mynas feeding on Coconut Rhinoceros Beetle larvae

I was turning my compost heap this morning when I came across the larvae of the Coconut Rhinoceros Beetle (Oryctes rhinoceros). I placed them in a container, planning to observe their development (below).

Rhinoceros Beetle larvae-compost pit

It was then that the resident Javan Myna (Acridotheres javanicus) pair made its presence known when the attending juvenile started begging loudly.

They were obviously after the compost fauna that I exposed. The most obvious of these are the Coconut Rhinoceros Beetle larvae. These larvae are usually buried deep inside the rotting compost and seldom encountered by birds. Only when the larvae complete their life cycles will they emerge as beetles.

I got 8 of the smallest larvae, placed them on a shallow layer of compost and left my video-cam on (see above). As soon as I left the scene, the mynas flew in and seek out the larvae.

1 MynaJ-mandibles-part-soil

They used their mandibles, opening them in the soil to expose the larvae (see above and video at 00:15; 1:00 and 1:54). The latter were then picked up, beaten into submission before swallowing.

3 MynaJ-RhinoLarvae

The adults also fed the begging juvenile that generally stood waiting to be fed (above). Only once did I see the juvenile looking for a larva but without success.

YC Wee
24th August 2017

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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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