Coraciiformes Taxon Advisory Group -
Wreathed Hornbill (Rhyticeros undulatus)
SSP Manager: Eric Kowalczyk - Woodland Park Zoo
Other common names in use include: Bar-throated wreathed hornbill, Wreathed hornbill, and Northern waved hornbill.
Kemp (1995) summarized the confusion in taxonomy of Rhyticeros subruficollis (Plain-pouched wreathed hornbill) which closely resembles the sympatric R. undulatus. From 1953 to about 1969, R. subruficollis was united with R. undulatus. This could have resulted in some misidentification of these two species in older records. Kemp (in del Hoya et al 2001) lists this bird in the genus, Rhyticeros.
Adult male: crown and nape rufous, face and foreneck white to cream-colored; body and wings black; tail white; bill, with casque a series of low wreaths (9-11) across base and obvious ridges across base of mandibles, pale yellow with dark orange brown base and ridges; bare circumorbital skin red with pink eyelids; inflated bare throat skin yellow with interrupted blue-black band across center; eyes dark red with narrow yellow inner rim; legs and feet dark olive-gray.
Adult female: similar to male but smaller; head and neck black; circumorbital skin flesh colored; throat skin blue with interrupted blue-black band across center; eyes dark brown with narrow blue inner rim..
Immature: plumage like adult male for both sexes but casque undeveloped; bill white to pale yellow; facial skin like adult male with lighter bands down sides of throat; eyes pale blue. Immature female begins molting to adult plumage within 7-8 months after fledging (Kemp 1995).
Although wreathed hornbills are not currently endangered, the species could be threatened in the future by habitat loss. This species has a large range, but habitat loss caused by deforestation is resulting in a decline in wild wreathed hornbill populations in Southeast Asia.
Due to similarity in appearance to Rhyticeros subruficollis, there is some confusion about the range of these two species. In the western part of the two ranges, there is overlap in eastern India southeast through Bhutan, Myanmar, Thailand, and possibly Peninsular Malaysia, and Sumatra. The range of A. undulatus continues east to Java, Bali, and Borneo. This species prefers primary evergreen forest up to 1675m. It is widespread but generally uncommon and as with the other birds in this genus, nomadism makes assessment of density difficult. Kemp (1995) suggests that the results of population studies obtained by surveying only communal day and night roosts may lead to exaggerated abundance figures.
Preferential habitat is extensive primary evergreen forests in the foothills and mountains at elevations up to approximately 2500 meters. They have been recorded breeding in selectively logged forests but their nests are frequently destroyed by logging operations in these areas.
The first recorded successful hatching of this species was at the New York Zoological Park in 1977 (Bell and Bruning 1978).
Presently the Regional Collection Plan lists this species in the DERP category. A Population Management Plan (PMP) was completed in May 2005 with the assistance from Colleen Lynch at the Population Management Center. As of early 2011, this studbook covers 135 historical records, of which, 17.15.0 living birds in 13 institutions.
Presently there are four successful living breeding pairs (at St. Catherine's Wildlife Center #65 & 75; at Atlanta #50 & 49; at San Diego Wild Animal Park #103 & 51; and at Oakland Zoo, #95, 59). Noteworthy, in 2008, the pair at St. Catherine's had a five egg clutch of which four eggs hatched and two chicks survived!
In 1999, Irena Pavlin of Ljublana Zoo, Slovenia published the first edition regional European studbook for this species.