Unearthing Tabon Facts

In a remote island in Sulu Sea lies a nesting field of the Tabon Scrubfowl. Tabon is a local name given to a large, ground-dwelling bird that has huge (mega) feet (pode). Yes, it is a bird that belongs to a group called Megapodes. They have unique nesting habits of burying eggs in the sand, incubating eggs by using heat from the environment and for having a young that is entirely independent after hatching (Bashari et al 2017). This behavior has made the Tabon a fascinating bird to study. Here’s some of the information compiled over five years of monitoring breeding populations, observations and visits to remote islands and forests habitats in the Philippines. Find out some of the interesting facts uncovered on this mystery bird.  


 

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.

 


An adult Tabon (Megapodius cumingii cumingii) in Banwa Private Island. Photo by Godfrey Jakosalem. 


Breeding behavior  

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. 

 


A Tabon nest mound in Greater Sta. Cruz Island in Greater Sta. Cruz and Little Sta. Cruz Islands Protected Landscape and Seascape in Zamboanga City. Photo by Lisa J. Paguntalan.  


Tabon birds are very neat. They spend time removing debris to expose the fine sand in the nesting area. Every bit of leaf or twig that clutters on the nest mound were scratched away. As soon as the area is cleared, they start scratching and moving sand until a burrow is created.


During breeding season, as soon as the day breaks, the first Tabon would land on the nesting field and start digging. Their strong and powerful feet effectively move sand that at some point, only sand flying out from the hole can be seen. When the sun is up and warming the sand fast, the birds slowly leave the nesting field until not one individual is left by mid-morning. They remain in nearby bushes or move around to forage for food. They are back in the nesting field around 15hr00 until sundown. This goes on throughout the breeding season that starts from January to late October. By late October, Tabon starts to leave the island and the nesting field is empty for at least two months. Tabon moves back to the island on early January and the cycle repeats.   

 


A nest field of Tabon in Banwa Private Island in late October. Photo by Lisa J. Paguntalan.

 

Egg laying and hatching 

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. 

 

When the eggs hatched, the chick dig its way up out of the sand burrow. Hatching happens at night or when it is still dark. We suspect that Tabon chicks emerged when it is still dark to avoid predators. As soon as the chick emerges, it runs quickly to the nearby bushes. It is immediately independent from its parents and forages for food on its own. It remains close to the nesting field until it has shed most of its down feathers. 

 

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.















Barred Rail. Photo by Godfrey Jakosalem. 


The Tabon generally moved around and search for food in pairs. Newly hatched chicks were often encountered solitarily and always under the cover of dense vegetation close to the breeding sites. Immature birds move alone or in pairs. They feed on a variety of food from seeds, shoots, larvae and adult insects, termites, beetles, worms and small snails. 


Conservation Implications  

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.  


The information presented here were taken from a 4-year study jointly conducted by Philippines Biodiversity Conservation Foundation Inc. and Aquos Foundation Inc. and from personal observations of Lisa Paguntalan conducted in Danjugan Island with Philippines Reef and Rainforest Conservation Foundation Inc. (PRRCFI); Baguan Island in Turtle Islands Wildlife Sanctuary and Greater Sta. Cruz Island in Greater Sta. Cruz and Little Sta. Cruz Protected Landscape and Seascape with the Provincial Environment and Natural Resources – Zamboanga Sibugay, DENR Region 9 and the City Environment Office of Zamboanga City. 


References

 

Aala, A. (2001). Behavioral and habitat analysis of Tabon bird (Philippines). Agricultural Science and TechnologyPCCARD -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 & McGowan, P.J.K (1995) Megapodes. An action plan for their conservation 1995 – 1996. Gland: IUCN. 


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.


Dekker, R.W.R.J., Fuller, R.A. & Baker, G.C. (Eds). (2000). Megapodes: status survey and Conservation Action Plan 2000-2004 WPA/BirdLife/SSC Megapode Specialist Group. IUCN, Gland, Switzerland and Cambridge, U.K. and the World Pheasant Association, Reading, UK. Vii+ 39pp. 


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. Forktail13: 13-16. 


Healey, C. (1994). Dispersal of newly hatched Orange-footed Scrubfowl Megapodius reinwardt. EMU. Vol. 94: 220-221. 


IUCN. 2016. The IUCN Red List of Threatened Species. Version 2016-3. Retrieved from: iucnredlist.org on 7 December 2016.


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. 

 

Author: Lisa Paguntalan