Wreathed Hornbill(Rhyticeros undulatus)
Wreathed hornbill measure 75-85 cm in length. Male wreathed hornbill weighs 1.6-3.6 kg while female weighs 1.3-2.7 kg. Its back, wings, and abdomen are black with a metallic green tinge and a long white tail. Its long beak is pale white to yellowish. Its casque has low folds and clear, vertical dark orange-brown wrinkles on both upper and lower mandibles.
The feet are grayish green. Male wreathed hornbill has a brick red crown and nape with white to cream-colored face and neck. Its circumorbital skin is red with pink eyelids. The male’s iris is dark red with a narrow blue ring. Underneath the bill is a yellow, featherless gular pouch with broken blue-black lines across the middle. Female wreathed hornbill is smaller in size. Its head and neck are black with a blue gular pouch, with similar black lines as the male. The female’s circumorbital skin is red with dark brown iris and a narrow blue ring. They are also known as the bar-pouched wreathed hornbill.
Habitat
In Indonesia, wreathed hornbill occurs in Kalimantan, Sumatra, Java and Bali (including a number of offshore islands). The species lives in lowland forests and hills up to 2,000 m asl. Its range extends to southern Bhutan, eastern India, southwestern China, Southeast Asia, and the Malay Peninsula.
Diet
The wreathed hornbill eats fruits including figs and fruits of the walnut family, ironwood, and mahogany trees. In Kalimantan, its primary food is lipid-rich fruits available during certain fruiting seasons. This hornbill species also eats small animals including bird eggs, small birds, tree frogs, and small bats, snakes, lizards, and invertebrates.
Breeding
During the breeding season, wreathed hornbills need large and tall trees with natural cavities. The hole is then plastered by the female using its feces and food remains. The female lays 2 eggs but usually only 1 chick survives into adulthood. The species spends 111-137 days nesting: 13-14 days to prepare the nest and lay eggs, 40 days incubation, and 90 days raising the chicks. In Kalimantan the breeding season lasts from January to May when fruit is abundant. Meanwhile breeding season in Sumatra is year-long except for December, and January, July-September in Java.
Population
According to the IUCN Red List, they are classed as Vulnerable(VU). The global population size has not been quantified, but the species is reported to be locally common in several areas across its wide range. The population is suspected to be in decline owing to ongoing habitat destruction and fragmentation. An analysis of deforestation between 2000 and 2012 estimated forest loss within the species's range at 32.8% over three generations (57 years). The rate of population decline is suspected to be greater than this because the species is intolerant of degraded and secondary habitat, but requires large tracts of undisturbed forest. In addition, it is also threatened by hunting. Thus, the rate of decline is precautionarily placed in the band 30-49% over three generations. Since this species has a long generation length, with three generations stretching over 57 years, there is insufficient evidence to calculate the magnitude of reduction over the past three generations. Assuming the recent rate of decline remains constant, the species is projected to decline by 30-49% over the next three generations.
Threats
Forest destruction in the Sunda region has been extensive as a result of commercial and illegal logging, conversion to agriculture (particularly plantations) and increasing human population pressure. The species generally prefers areas with extensive forest cover, while it avoids areas with even low human population. The species has a very large home range and therefore requires large tracts of undisturbed forest. Its preferred lowland forest habitat is particularly impacted by deforestation, even within protected areas. An analysis of forest loss from 2000 to 2012 estimated deforestation within the species's range at 32.8% over three generations. In north-eastern India, only 5% of the landscape offers suitable habitat. There, the species has disappeared from places where it used to be common, while it declined in abundance at sites where it still persists. Even though the species is less hunted than the Great Hornbill, hunting poses a substantial threat. A survey in north-eastern India found that the species is mainly targeted for its meat or as a trophy. Apart from that, its feathers are used as for cultural reasons by local communities and and its fat is highly prized for medical purposes. The species may also be taken as bycatch by hunters targeting Helmeted Hornbill.
Conservation
Conservation Actions Underway
CITES Appendix II. Occurs in several protected areas across its range, including Khao Yai National Park in Thailand, Ulu Belum and Gunung Mulu National Parks in Malaysia and Bali Barat National Park in Bali.
Conservation Actions Proposed
Monitor populations across its range to determine the magnitude of declines and rates of range contraction. Campaign for the protection of remaining extensive tracts of forest throughout its range, including lowland and adjacent foothill forest. Develop a programme to reduce hunting of the species through raising awareness of the status of the species within communities that target the species.