Helmeted Hornbill (Rhinoplax vigil) (BirdLife species factsheet) is currently classified as Near Threatened as a result of a suspected moderate decline due to habitat loss and hunting pressure.
The species occurs in primary semi-evergreen and evergreen lowland forest, up to 1,500 m. It prefers rugged terrain, especially in foothills, and can persist locally in selectively logged forest. The species is confined to the Sundaic lowlands, where it is known from south Tenasserim (Myanmar), peninsular Thailand, Sabah, Sarawak and Peninsular Malaysia, Singapore, Kalimantan and Sumatra (Indonesia) and Brunei (BirdLife International 2001). It is generally scarce and occurs at low densities even in optimal habitat. The population size of this this species has not been quantified.
A forthcoming analysis of remote sensing data on forest loss (Tracewski et al. in prep) has estimated that the total area of forest within the range of R. vigil has declined from c.643,000km2 in 2000 to c.565,000km2 in 2012, representing a loss of c.12% of forest habitat available to this forest-dependent species. Assuming that the rate of forest loss is constant, this represents a loss of c.25% of forest habitat within the species’s range across three generation lengths (26.1 years).
The species is known to be targeted by hunters for its feathers and for its solid ‘ivory’ casque, which is used to produce handicrafts and traded with China. Previously, it was thought that capture rates may be relatively low as a result of the species becoming shy over centuries of hunting. However, recent reports suggest that the species is currently being traded at a large scale. A report by the Environmental Investigation Agency (2015) revealed that hornbill casques are being traded in Laos and a 2013 study found that around 6,000 helmeted hornbills were traded in 2013 in West Kalimantan alone (Y. Hadiprakarsa in: Hii, 2015). Given the low population densities of this species, it is probable that hunting at this scale is contributing to strong population declines in at least parts of its range.
Proposed change and reasoning:
Given the rate of forest lost within the species’s range and the additional pressure caused by hunting, it is likely that the species has undergone a reduction of at least 30% and possibly more than 50% over a period of three generations (26.1 years), and that the population will continue to decline. It is therefore proposed that the species is uplisted to Vulnerable or Endangered under Criteria A2, A3 and A4.
Additional information and comments on this proposal are welcomed.
BirdLife International. 2001. Threatened birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.
Environmental Investigation Agency (EIA). 2015. Sin City – Illegal wildlife trade in Laos’ Golden Triangle Special Economic Zone. London, UK.
Hii, R. 2015. Helmeted hornbills on the verge of extinction. Huffington Post, 5th March 2015. Retrieved from http://www.huffingtonpost.com/robert-hii/helmeted-hornbills-on-the_b_6804302.html on 30th June 2015.
Tracewski,L., Butchart, S.H.M., Di Marco, M., Ficetola,G.F., Rondinini,C., Symes, A., Wheatley, H., Beresford, A.E. & Buchanan, G.M. in prep. Quantifying the impact of 21st century deforestation on the extinction risk of terrestrial vertebrates. Manuscript in preparation.
Discussion written by Hannah Wheatley, BirdLife International 2015.