Due to the difficulty in observing this bird, almost nothing is known of its nesting habits. However it is often heard, for its call, a series of repeated, gradually accelerating toks ending in a burst of insane laughter, can be heard for nearly a mile. Furthermore, its two excessively long tail feathers moult alternately, so that only one is presentable at a time.Ī fruit-eating bird, it spends its life in the highest trees and hence is seldom seen. And as the bases of its flight feathers are left bare, it makes a terrific noise when flying which has been compared to the sound of an approaching train. It has no feathers at all on most of its neck and back. Even a devoted ornithologist has described it as “a perfect nightmare of a bird.” Measuring nearly five feet from the end of its beak to the tip of its tail, it has coarse plumage, primarily of a dirty reddish black, except tor a white stomach and white bands on its tail. It is not only one of the largest birds in the jungles of Southeast Asia, but it is certainly the ugliest, in spite of the highly complimentary portrait of it shown in Figure 2. The Helmeted Hornbill is without doubt the most extraordinary member of a remarkable family. (The casques of several other species of Hornbill are far more imposing, but they are hollow or filled with spongy tissue.) The single exception is the Helmeted Hornbill, Rhinoplax vigil. This is contained in a solid casque or epithema at the front of the head above the beak. There are at least sixty varieties of Hornbill birds in the Eastern Hemisphere, but only one of these bears the “ivory,” a hard, carvable substance which is almost as dense as elephant ivory. Thus we are very fortunate in having a fine example in the University Museum (see Figure 1). Carvings in it were always highly valued and they have now become exceedingly rare. Assuming the recent rate of decline remains constant, the species is projected to decline by 35-40% over the next three generations.The strange substance called “hornbill ivory” was formerly an important commodity in Asiatic trade, and it was extensively carved, especially in China and the East Indies. Since this species has a long generation length, with three generations stretching over 42 years, there is insufficient evidence to calculate the magnitude of reduction over the past three generations. The rate of decline is therefore placed in the band 35-40% over three generations. Thus, its actual rate of population decline is likely greater than the estimate decline based on forest loss alone, possibly exceeding 35% over three generations. Being largely restricted to primary forests and intolerant of habitat conversion, the species is additionally threatened by hunting. Trend justification: An analysis of deforestation between 20 estimated forest loss within the species's range at a rate equivalent to 35% over three generation lengths (42 years) (Tracewski et al. In Sabah, Crocker Range Park and Tawau Hills Park had population densities of 0.94 individuals/km 2 and 5.67 individuals/km 2 respectively (Lakim & Biun 2005). In Sarawak, Upper Baram and Batang Ai National Park had population densities of 0.27 individuals/km 2 (Chin & Jantan 2001) and 0.96 individuals/km 2 (Meredith 1995) respectively. In Kuala Lompat (Krau Wildlife Reserve) the population density was 2 individuals/km 2 (Medway & Wells 1971). In Peninsular Malaysia, Sungai Tekam Forestry Concession (Pahang State) population density was found to be 1.6 groups/km 2 in primary forest and 2.3, 1.8, 1.2, 0.4 groups/km 2 in 0-6 month, 1-2 year, 3-4, 5-6-year-old logged forest respectively (Johns 1987). The species is widespread throughout its range, but occurs at low densities, even in suitable habitat (Poonswad et al. Population justification: The population size of this species has not been quantified. Decline % (10 years/3 generations future)ĭecline % (10 years/3 generations past and future)
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