Unearthing Tabon Facts
An adult Tabon (Megapodius cumingii pusillus) in danjugan island. Photo by Godfrey Jakosalem.
How many kinds are there?
There are currently seven recognized subspecies of Tabon distributed through North Borneo, Sulawesi and the Philippines (Bashariet al 2017; Kennedy et al. 2000; Jones et al. 1995). There are two subspecies found in the Philippines: Megapodius cumingii cumingii on Palawan Group of Islands and Megapodius cumingii pusillus for the rest of the country.
There are two known breeding strategies used by Tabon: using heat produced by decomposition of organic matter and burying the egg in a field of sand directly exposed through solar radiation (Bashari et al. 2017). In our observations in the Philippines, we only observed the used of solar radiation in incubating eggs buried in mounds (see photo below) or sand burrows in nesting fields.
Copulation usually lasts for about 5-8 seconds either inside or outside of the nesting field. Only one large egg is laid by the female. There were however exceptional cases when two eggs were laid in the same mound. Egg-laying happens just before dusk. The female quickly buries the egg with sand before leaving the nest to roost in nearby trees.
Predators
We identified at least three predators of eggs and chicks: Barred Rail Gallirallus torquatos, Pacific Reef Egret Egretta sacra and the Northern Boobok Ninox japonica. There was one occasion when we observe five Barred Rails working in groups to prey on an exposed Tabon egg. Two rails were keeping the Tabon busy while three other individuals work on the sides to further expose the egg. As soon as the egg was exposed, the Barred Rails feasted on it. On another occasion, a Pacific Reef Egret fed on an exposed Tabon egg and a Northern Boobok was photographed feeding on a Tabon chick during daytime.
The International Union for Conservation of Nature (IUCN) currently listed Tabon as Least Concern but pointed out that populations are declining (IUCN 2019). Populations are now confined to a few coastal beaches and in small, isolated islets and islands with few or no inhabitants (Kennedy et al. 2000; Torres and Mendoza 2000; Tabayag and Cruz 2013). Coastal beach forests and smaller islands play a crucial role in the conservation of Tabon. More studies are needed to understand local movements and the extent of habitat use on smaller islands and in forests on the adjacent mainland.
References
Aala, A. (2001). Behavioral and habitat analysis of Tabon bird (Philippines). Agricultural Science and Technology. PCCARD -DOST: 81-82.
Bashari, H., Mangangue, B. & Mangangue, A. (2017). Incubation strategy of Philippine Scrubfowl Megapodius cumingi on Manumpitaeng Islet, North Sulawesi, Indonesia. Birding Asia 27:82-85.
Dekker, RWRJ. and Brown, T.G. (1992) Megapode phylogeny and interpretation of Incubation strategies. Proceedings of the First International Megapode Symposium. Christchurch, New Zealand. Zool Verh. 278: 19-31.
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del Hoyo, J.; Elliot, A. & Sargatal, J. (1992). Handbook of the birds of the world, Vol. 1: Ostrich to Ducks. Barcelona: Lynx Edicions.
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. & Fishpool, L.D.C. (2014). HBW and BirdLife International illustrated checklist of the birds of the world. Barcelona: Lynx Editions and BirdLife International.
Endrawan, M., Masala, V. & L Pesik (1998). Observations on the breeding behavior of Sula Scrubfowl Megapodius bernsteinii in the Benggai Islands, Sulawesi, Indonesia. Forktail. 13: 13-16.
Healey, C. (1994). Dispersal of newly hatched Orange-footed Scrubfowl Megapodius reinwardt. EMU. Vol. 94: 220-221.
Jones, D.N., Dekker R.W.R.J. & Roselaar C.S. eds. (1995). The Megapodes. Oxford: Oxford University Press.
Kennedy, R.S. and Gonzales, P.C., Dickinson, E.C., Miranda, Jr., H.C. & Fisher, T.H. (2000). A Guide to the Birds of the Philippines. Oxford. Oxford University Press.
King, T., S. Tyler, Turner, C., O’Malley, R. & Raines, P. (2003). Bird Records from Danjugan Island, Negros Occidental, Philippines. Silliman Journal44(1): 117-135.
Lloyd, H., Torres-Sovero, L.H. & Faka”osi, S. (2011). Conservation Strategy for the Polynesian Megapode Megapodius pritchardii on Niuafo”ou, Tonga. World Pheasant Association, Newcastle, UK and Tonga Community Development Trust, Tongatapu, Tonga. 41pp.
Matillano, J. D., Espinosa, A.F. & Gonzales, B.J. (2008). The birds of Pandan Island, Honda Bay, Palawan. Palawan Knowledge Platform. Palawan Council for Sustainable Development. Retrieved from https://pkp.pcsd.gov.phon 16 May 2020.
Sinclair, J.R., O’Brien, T.G. & Kinnaird, M.F. (1999). Observations on the breeding biology of the Philippine Scrubfowl (M. cumingii) in North Sulawesi, Indonesia. Tropical Biology. 6 (1&2): 87-97.
Tabayag, E. & Cruz, R. (2013). Population estimate and habitat characterization of Tabon Scrubfowl Megapodius cumingi in small islands, Province of Palawan: Palawan Council for Sustainable Development.
Torres, D. S., & Mendoza, M.C. (2000). Notes on the distribution, abundance and behavior of Tabon Scrubfowl (Megapodius cumingii) in Arreceffi Island, Baron alo, Puerto Princesa City, Philippines. Sylvatrop Technical journal of Philippine Ecosystems and Natural Resources10(1&2): 78-87.
