The threat maleo
The size of the egg makes it in attractive source of food for humans and maleo nesting beaches have probably been explotted since man first arrived on Celebes. Unfortunately, however, over-exploitation has been a common phenomenon: for example, the beach at the batuputih just north of the present Tangkoko-Batuangus reserve, where Alfred Wallace watched maleo nesting in 1859, was at one time visited by egg collectors in an apparently more or less sustainable manner, but within six years at a settlement being established at batuputih in 1913, maleos no longer visited the beach (MacKinnon 1978). In 1947 about 10,000 eggs were laid in 2 ha of the panua Reserve on the coast near Marisa, Gorontalo (Uno 1949), but the present total less than 10% of this (Anon. 1982a). the total number of breeding hens is between 25% and 67% of the total 40 years ago (Wiriosoepartho 1980).
The largest site, at bakiriang, is only a few kilometers away from a transmigration site. The lowland forest the birds depend on behind the beach is being felled an unless this is protected the demise of this populatin seems almost certain. The Bakiriang site is so special that, until 50 years ago, the raja of Banggai, on Peleng island 100 km away, determined who should collect the eggs and he received a revenue from the eggs collected. The first 100 eggs were sent to the Raja and only after he had approved these could they be consumed by local people. Although the Banggai Rajas were notorious pirates and unacceptable in many ways, they were among Indonesia’s first resource managers. Now, however, eggs are taken despite legal prohibition and they can be found, wrapped in individual palm-leaf baskets, in the markets of ujung Pandang and even Jakarta.
Experiments by the head of the Gorontalo Forest service in the mid-70s showed that maleo eggs could be collected and reburied in a cage so that predation was avoided, and then hatched with significant rates of success (MacKinnon 1978). This was tried again in the Tangkoko-Batuangus Reserve and a hatching rate of 78% was achieved. This technique, together with the control of pig and lizard predators and the clearing of undergrowth to increase the area with a suitably high soil temperature, could make a significant contribution to increasing maleo populations.
Work is currently being conducted in Bogani Nani Wartabone National Park on the management of an inland of maleo birds and results are awaited with interest.
Bibliography
Guillemard, F.H.H. 1889. the cruise of the Marchesa to kamschatka and New Guinea with notice of Formosa, Liu-liu, and various islands of the Malay Archipelago. London: murray
Wathley, R.J. 1983a. Ornithological notes from sulawesi. Emu
1983b. Sandbox incubator. Anim Kingdom june/July
Wiriosoepartho, A.S. 1979. Pengamatan habitat dan tingkah laku bertelur maleo (Macrocephalon maleo) di kompleks hutan dumoga, Sulawesi Utara, Laporan no. 315 Bogor: lembaga Penelitian Hutan
Wallacea, A.R. 1869. the malay Archipelago. The land of the orangutan and the birds of paradise. A narrative of travel with studies of man and nature . London: macMillan. Republished 1962 by dover, New York
Wiriosoepatho, A.S. 1980. penggunaan habitat dalam berbagai macam aktivitas oleh macrocephalon maleo sal. Muller di Cagar alam Panua, Sulaweai Utara. Laporan no. 356 Lembaga Penelitian Hutan. Bogor
MacKinnon, J.R. 1978. sulawesi megapodes. World Pheasant Assoc
Uno, A. 1949. het natuurmonument Panoea (N. Celebes) en het maleohen (Macrocephalon maleo Sall. Muller) in het bijzonder. Tectona
Anon. 1982a. National Conservation Plan for Indonesia vol.v. sulawesi, FAO: Bogor
MacKinnon, J.R. 1981a. methods for the conservation of maleo birds, Macrocephalon maleo on the island of sulawesi, Indonesia. Biol. Conserv
Birdbody berisi informasi seputar pariwisata, hotel, kuliner dan budaya khas Indonesia
The Struggle Chick Maleo From Predators
The struggle chick maleo
Maleos are communal nesters and on the largest known site at Bakiriang on the south coast of the north-east peninsula, more than 600 birds nest early in the year with the holes only two or three metres apart. Two hundred of the birds nest on just 1 ha of sand (Watling 1983).
The surface of a sandy beach can become extremely hot, over 50 celcius degree and 80 celcius degree on white and black sand respectively (MacKinnon 1978), yet just a few centimeters below the surface, the temperature is relatively stable at about 36 celcius degree. It seems as if most eggs, on beachs or elsewhere, are laid in positions where the temperature is between 32 celcius degree and 38 celcius degree (MacKinnon 1978, Wiriosoepartho 1980). The depth of the hole might be thought to be critical, and it has been suggested that the bare head of the maleo is efficient at sensing temperature but, in reality, the exact depth and temperature (within certain limits) are not so critical. Instead it seems that the eggs are laid as deep as possible for protection against predators.
Hatching takes about three months and if the chicks survive the one or two day scramble to the surface, for ants are a major predator of chicks in the ground (R. Dekker pers. Comm.), they are able to fly away immediately, already having adult plumage the manner in which they ‘explode’ from the sand and rush away is probably an adaption to avoid the attention of predators (Watling 1983). The great size of the egg is related to the need to produce a chick strong enough to struggle up to the surface (Guillemard 1889).
Maleos are communal nesters and on the largest known site at Bakiriang on the south coast of the north-east peninsula, more than 600 birds nest early in the year with the holes only two or three metres apart. Two hundred of the birds nest on just 1 ha of sand (Watling 1983).
The surface of a sandy beach can become extremely hot, over 50 celcius degree and 80 celcius degree on white and black sand respectively (MacKinnon 1978), yet just a few centimeters below the surface, the temperature is relatively stable at about 36 celcius degree. It seems as if most eggs, on beachs or elsewhere, are laid in positions where the temperature is between 32 celcius degree and 38 celcius degree (MacKinnon 1978, Wiriosoepartho 1980). The depth of the hole might be thought to be critical, and it has been suggested that the bare head of the maleo is efficient at sensing temperature but, in reality, the exact depth and temperature (within certain limits) are not so critical. Instead it seems that the eggs are laid as deep as possible for protection against predators.
Hatching takes about three months and if the chicks survive the one or two day scramble to the surface, for ants are a major predator of chicks in the ground (R. Dekker pers. Comm.), they are able to fly away immediately, already having adult plumage the manner in which they ‘explode’ from the sand and rush away is probably an adaption to avoid the attention of predators (Watling 1983). The great size of the egg is related to the need to produce a chick strong enough to struggle up to the surface (Guillemard 1889).
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