The IUCN Red List of Threatened Species™ ISSN 2307-8235 (online) IUCN 2008: T22682464A134206677 Scope: Global Language: English Rhinoplax vigil, Helmeted Hornbill Assessment by: BirdLife International View on www.iucnredlist.org Citation: BirdLife International. 2018. Rhinoplax vigil. The IUCN Red List of Threatened Species 2018: e.T22682464A134206677. http://dx.doi.org/10.2305/IUCN.UK.2018- 2.RLTS.T22682464A134206677.en Copyright: © 2018 International Union for Conservation of Nature and Natural Resources Reproduction of this publication for educational or other non-commercial purposes is authorized without prior written permission from the copyright holder provided the source is fully acknowledged. Reproduction of this publication for resale, reposting or other commercial purposes is prohibited without prior written permission from the copyright holder. For further details see Terms of Use. 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THE IUCN RED LIST OF THREATENED SPECIES™ Taxonomy Kingdom Phylum Class Order Family Animalia Chordata Aves Bucerotiformes Bucerotidae Taxon Name: Rhinoplax vigil (Forster, 1781) Synonym(s): • Buceros vigil Forster, 1781 — BirdLife International (2000) • Buceros vigil ssp. vigil Forster, 1781 — Collar and Andrew (1988) • Buceros vigil ssp. vigil Forster, 1781 — Sibley and Monroe (1990, 1993) • Buceros vigil ssp. vigil Forster, 1781 — Collar et al. (1994) Common Name(s): • English: Helmeted Hornbill • Spanish: Cálao de Casco Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK. Identification Information: 110-120 cm. Very large hornbill. Mostly dark brown and white with long central tail feathers. Distinctive high red casque, yellow at front. Male with bare red areas on neck, female with pale turquoise skin on head and neck (Kemp et al. 2014). Voice A long series of rather high-pitched "pooh" calls which suddenly shift to several bisyllabic “poohooh” calls, ending in a harsh, cackling laugh (Kemp et al. 2014). Assessment Information Red List Category & Criteria: Critically Endangered A3cd ver 3.1 Year Published: 2018 Date Assessed: August 19, 2018 Justification: This species has been uplisted from Near Threatened to Critically Endangered owing to severe hunting pressure and habitat loss. The level of hunting is expected to increase and spread across the range, given the value that is placed on the species's casque in illegal trade. Previously Published Red List Assessments 2017 – Critically Endangered (CR) http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T22682464A117225617.en 2016 – Critically Endangered (CR) http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22682464A92947540.en 2015 – Critically Endangered (CR) © The IUCN Red List of Threatened Species: Rhinoplax vigil – published in 2018. 1 http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22682464A134206677.en http://dx.doi.org/10.2305/IUCN.UK.2015.RLTS.T22682464A84412814.en 2012 – Near Threatened (NT) http://dx.doi.org/10.2305/IUCN.UK.2012-1.RLTS.T22682464A38073187.en 2008 – Near Threatened (NT) 2004 – Near Threatened (NT) 2000 – Lower Risk/near threatened (LR/nt) 1994 – Lower Risk/near threatened (LR/nt) 1988 – Threatened (T) Geographic Range Range Description: This 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, occurring at low densities even in optimal habitat, and is is the least commonly encountered of the forest hornbills in peninsular Malaysia (D. L. Yong in litt. 2016). Country Occurrence: Native: Brunei Darussalam; Indonesia; Malaysia; Myanmar; Thailand Regionally extinct: Singapore © The IUCN Red List of Threatened Species: Rhinoplax vigil – published in 2018. 2 http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22682464A134206677.en Distribution Map Rhinoplax vigil © The IUCN Red List of Threatened Species: Rhinoplax vigil – published in 2018. 3 http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22682464A134206677.en Population The population size of this species has not been quantified. In prime habitat, the density varies from 0.19 to 2.6 individuals per km2 (references in Jain et al. 2018). However, populations subjected to even low hunting pressure have been demonstrated to have greatly suppressed densities, e.g. 0.3 birds per km2 (Johns 2004). Current hunting pressure is far higher than reported in that study (Jain et al. 2018). Trend Justification The population is predicted to undergo an extremely rapid and severe decline over the next three generations (59 years) as a result of intense hunting pressure and habitat loss. On Sumatra, the species has almost disappeared from habitats where it was previously abundant (J. Eaton in litt. 2015). The number of Helmeted Hornbills in the illegal trade indicate that severe declines and local extinctions are likely to be the norm across the range. Current Population Trend: Decreasing Habitat and Ecology (see Appendix for additional information) It occurs in primary semi-evergreen and evergreen lowland forest, in elevations up to 1,500 m. In particular, it prefers rugged terrain, especially in foothills, and can persist locally in selectively logged forest, but avoids open areas, disturbed forest and peatswamp (Lum and Poonswad 2005, Kinnaird and O'Brien 2007, Poonswad et al. 2013). It feeds on fruits, especially figs, which make up the majority of the diet (Kitamura et al. 2011, Poonswad et al. 2013) and travels widely in search for fruiting trees, which makes this species a key seed disperser in lowland forest. It has also been recorded feeding on small animals including squirrels, snakes and birds and even other hornbill species (Kemp et al. 2014, Utoyo et al. 2017). Helmeted Hornbills form monagamous breeding pairs. The female is sealed inside the nest chamber for the entire incubating and chick-rearing period, which can be over 160 days (Chong 2011). During this time, she is dependent upon the male for food for herself and the chicks (Collar 2015). In Thailand, the species mainly uses trees in the Diptocarpaceae family, particularly Hopea spp. and Shorea spp. (Meijaard et al. 2005), and appears to require a perch at the entrance upon which the male can perch (Jain et al. 2018). No reports of breeding in captivity or of accepting artificial nestboxes (Jain et al. 2018). Systems: Terrestrial Threats (see Appendix for additional information) The species is heavily targeted by hunters and illegally traded. The species has a solid horn or casque on the upper side of its beak, which is highly prized. China is the biggest consumer of the casques, which are often carved for decorations or used in traditional medicine (Hughes 2015). Currently, the trade in this species is centered on Indonesia, but will likely move to Malaysia once the supply of birds becomes limiting in Indonesia (S. Mahood in litt. 2015). Between March 2012 and August 2014, 1,117 heads/casques were seized in Indonesia during enforcement actions, and in the same period 1,053 heads/casques were confiscated in China (Beastall et al. 2016). It has also been recorded in trade in Laos (EIA 2015). Large numbers of hunters have been observed in the forests of Sumatra searching for this species (J. Eaton in litt. 2015), and in June 2015 a group of around 30 hunters was broken up in northern Sumatra (Hughes 2015). © The IUCN Red List of Threatened Species: Rhinoplax vigil – published in 2018. 4 http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22682464A134206677.en The trade network is thought to be largely managed by organised crime. This means that trade pressure is likely to continue, eventually reaching every part of the species's range, and will be very difficult to control (N. Collar in litt. 2015). Many traders seized have also been involved in the trade of other high- value wildlife such as Sumatran Tiger Panthera tigris sumatrae and Sunda Pangolin Manis javanica (Beastall et al. 2016). In West Kalimantan, it is thought that as many as 500 birds were being killed every month in 2013, resulting in an annual loss of 6,000 individuals (Y. Hadiprakarsa in litt. 2015, Hii 2015). There is no information to suggest that such levels of exploitation should be any different in other Indonesian provinces; indeed trade in hundreds of birds per month from Sumatra has been reported within the last year (N. Collar in litt. 2015). Owing to the species's breeding behaviour, hunting is likely to have a particularly severe impact: Breeding involves the female being incarcerated for c.160 days, while the male provisions the female and nestling in the nest. Although the female will break out of the nest should the male stop providing food, she is likely to be in heavy moult and her ability to survive will be seriously compromised. Thus, the killing of the male could lead to the subsequent death of both the chick and the female (Collar 2015). In addition to hunting the species for its casque, it is also targeted for its feathers. Although this trade is small, it exerts an additional pressure, which is also likely to contribute to population declines (Collar 2015).