Data Zone
Justification of Red List category
This species is currently listed as Near Threatened because it probably has a moderately small population which is declining owing to habitat loss and hunting. Further studies are urgently required to determine rates of decline and clarify threat levels.
Population justification
The population size of this species has not been quantified, but it is generally scarce or rare across most of its range, and only locally common at a handful of sites (Poonswad et al. 2013).
Trend justification
Despite a lack of data on trends, a slow to moderate decline is suspected to be occurring as a result of habitat loss and hunting pressure.
Anorrhinus austeni occurs in northeast India, west, north and east Myanmar, central and northern Thailand, Laos, Vietnam and Cambodia. In China there are specimen records from southern Xishuangbanna, south Yunnan and south-east Tibet from the mid 20th Century, but none have been reported in recent decades (P. Lo in litt. 2016). In India the species occurs in eastern Arunachal Pradesh, eastern and southern Assam, Nagaland, Mizoram and likely also in Manipur (Hussain et al. 2015, R. Naniwadekar and A. Datta in litt. 2016). Within Arunachal Pradesh Austen's Brown Hornbill occurs in Namdapha Tiger Reserve, Kamlang Wildlife Sanctuary, Tengapani, Turung, Rima and Miao Reserved Forests, and Hukanjury and Manmao forests (Naniwadekar et al. 2015); in Assam it occurs in Dehing Patkai Wildlife Sanctuary and adjacent Joypur Reserved Forest (Saikia and Devi 2011), Barail Wildlife Sanctuary (Hussain et al. 2015), Upper Dihing and Dumduma, Dangori, Kumsong and Dansiri Reserved Forests (Choudhury 2000, R. Naniwadekar and A. Datta in litt. 2016); in Nagaland it is reported from Intanki National Park and Tuensang District near the Myanmar border (R. Naniwadekar and A Datta in litt. 2016); in Mizoram records are from Lengteng (Sailo and Lalthanzara 2015) and Pualreng Wildlife Sanctuaries (R. Naniwadekar and A. Datta in litt. 2016), and also near Ngengpui Wildlife Sanctuary (Ved 2011); and in Manipur from Ukhrul District (Choudhury 2009).The status of the species is presently poorly known in Myanmar, while in Thailand local extinctions have been reported with Khao Yai National Park and Phu Khiao Wildlife Sanctuary retaining populations (Poonswad et al. 2013, R. Naniwadekar and A. Datta in litt. 2016, eBird 2017). The species was historically numerous in Laos and is currently considered locally common but declining, with recent records from Nam Kan National Protected Area (Timmins and Duckworth 2012) and Xe Xap National Biodiversity Conservation Area (Nielsen 2012). In Vietnam it is rare to uncommon, being reported from the Da Lat Plateau, Bidoup, Bach Ma, Phong Nha-Ke Bang and Cuc Phoung National Parks as well as Mang Den and Vu Ouang Nature Reserve (Eames 1995, Eames et al. 2001, R. Naniwadekar and A. Datta in litt. 2016). It is highly localised and scarce or rare in Cambodia, where there have been recent records from Phnom Aoral in the Cardamom Mountains and from the south east of the country (Goes 2013, eBird 2017). The species has been recorded at densities of 7.9 individuals per square kilometre in Arunachal Pradesh, India (Naniwadekar and Datta 2013) and 4.4 individuals per square kilometre at Khao Yai, Thailand (Poonswad et al. 2013).
This species inhabits evergreen broadleaved forest in foothills up to 1,000 m in India, 1,500 m in South-East Asia and 1,800 m in China. It is omnivorous, feeding on fruits, seeds and berries as well as arthropods, molluscs and small vertebrates. A cooperative breeder, multiple males provision a single nest (Poonswad et al. 2013). In Thailand the breeding season begins in February-March and ends in May-June, while in northeast India breeding takes places between April and July (Datta 2009). Dipterocarps are often used as nest trees, along with other large trees such as Cleistocalyx in Thailand or Ailanthus grandis in northeast India (Poonswad et al. 2013, R. Naniwadekar and A. Datta in litt. 2016). Whilst apparently able to breed in logged and degraded forest, nesting attempts in these habitats are often unsuccessful owing to human disturbance (Datta 2009).
This species is threatened by forest loss through intensive shifting agriculture, widespread logging activities and road building, and because of high levels of hunting in many parts of its range (Datta 2009, Poonswad et al. 2013, Naniwadekar et al. 2015).
Conservation Actions Underway
The species occurs in protected areas across its range, which appear to be particularly important for this species, with research indicating that the probability of habitat use outside of protected areas was lower than for sympatric hornbill species (Naniwadekar et al. in litt. 2016). Research on the ecology of the species has been undertaken at Khao Yai National Park in Thailand for over 20 years (Poonswad et al. 2013).
Conservation Actions Proposed
Conduct surveys throughout its range in order to clarify current status, especially in Myanmar and Laos. Repeat surveys and monitor populations at known sites in order to determine the magnitude of declines and rates of range contraction. Conduct ecological studies to determine habitat requirements and tolerance of secondary habitats. Assess potential risk from hunting and trapping. Grant protection to areas of suitable habitat to safeguard against logging and encroachment. Raise awareness of the species and its status in an effort to reduce hunting pressure.
Text account compilers
Gilroy, J., Khwaja, N., Harding, M., Martin, R., Taylor, J., Hermes, C.
Contributors
Lo, P., Datta, A., Naniwadekar, R.N.
Recommended citation
BirdLife International (2024) Species factsheet: Austen's Brown Hornbill Anorrhinus austeni. Downloaded from
https://datazone.birdlife.org/species/factsheet/austens-brown-hornbill-anorrhinus-austeni on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/11/2024.