Data Zone
Justification of Red List category
This species has a small range, confined to to just seven islands in the central Nicobar Island group. Within its limited range, slow rates of forest loss are ongoing and thought to be causing declines. Nonetheless, it remains common and much of its range is at least nominally protected. For these reasons it is listed as Near Threatened.
Population justification
The population size of this species has not previously been estimated, although it is among the most common forest species on the islands it occupies (Zaibin 2017, Goyal 2020). In total, approximately 330 km2 of forest lies within its range (per Global Forest Watch 2022); although no population density exists for this species, congenerics and other forest bulbuls in South-East Asia typically occur at densities of 20-100 birds/km2 (see Santini et al. 2018 data). Occupancy within the species range is likely to be high (postulated here to be 80-95%), thus the population size is likely to be c.5,300-31,400 birds, or c.3,500-20,000 mature individuals. The island of Katchall has the most forest (c.134 km2) and, using these same assumptions, is likely to host 1,400-8,000 mature individuals.
Trend justification
A total of 250 km2 of forest was lost on the Nicobar Islands between 1976 and 2014 (Reddy et al. 2016), although rates of forest loss since have been slower. In the three generations (11.7 years; Bird et al. 2020) to 2021, forest cover loss in this species' range was reduced by 3-4% (per Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). As a forest dependent species (see Goyal 2020), the rate of population reduction is thought to be similar and is placed here in an ongoing bracket of 1-9% over three generations.
This species is endemic to the Nancowry island group, part of the Nicobar Islands in the Bay of Bengal, India. It occurs on Camorta, Trinkat, Nancowry, Katchall, Teressa, Bompoka and Tillanchong.
It is a sedentary resident, primarily found in forest interior, although frequents edge habitats such as gardens, coconut and rubber plantations, around human habitation and occasionally grasslands, suggesting it is tolerant of some habitat degradation (P. Davidar in litt. 2020). It is ecologically separated from the non-native congener Pycnonotus jocosus that is restricted to edges and secondary habitats (Goyal et al. 2019). It is usually found singly or in pairs, but one recent observation concerned a loose flock of over 100 individuals. Its breeding behaviour has not been described but adults have been seen to feed nestlings and fledglings from late February to mid April (A. P. Zaibin in litt. 2012).
Clearance and conversion of forests for plantation agriculture (particularly rubber, coconut and cashew cultivation) and infrastructure development (including roads, human settlements and defence establishments) are the most serious long-term threats (Goyal 2020). Over 6 km2 of forest have been lost on Katchall to rubber plantations. Competition with the introduced Red-whiskered Bulbul Pycnonotus jocosus was previously thought to have contributed to the species' decline but a recent study (see Goyal et al. 2019) indicated that the two ecologically segregate themselves, with P. jocosus absent from primary forest types. It may be locally hunted by local people, especially children, although its small size renders it unattractive for consumption (per Goyal 2020).
Conservation Actions Underway
Listed as a Schedule–IV species in the Wildlife Protection Act of 1972 and is consequently denied high conservation importance by India. All the islands in the Nancowry group are designated tribal reserves, which legally prohibits commercial exploitation of natural resources, along with settlement or ownership of land by non-tribal people (Goyal 2020).
20 cm. Non-descript bulbul. Sooty-brown crown and whitish to pale yellow underparts. Similar spp. Juvenile Red-whiskered Bulbul Pycnonotus jocosus has short crest, white ear-coverts and underparts, blackish moustachial line and lateral breast-bar, dull reddish undertail-coverts and white-tipped outer tail feathers. Voice Chattering notes, recalling Black Bulbul H. leucocephalus.
Text account compilers
Berryman, A.
Contributors
Benstead, P., Davidar, P., Davidson, P., Gilroy, J., Khwaja, N., Mahood, S., Peet, N., Sankaran, R., Sivakumar, K., Symes, A., Tobias, J., Westrip, J.R.S. & Zaibin, A.
Recommended citation
BirdLife International (2024) Species factsheet: Nicobar Bulbul Ixos nicobariensis. Downloaded from
https://datazone.birdlife.org/species/factsheet/nicobar-bulbul-ixos-nicobariensis on 23/11/2024.
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 23/11/2024.