Justification of Red List Category
This species's prospects are currently uncertain as statistics on forest loss on Anjouan are unreliable. Recent evidence suggests that it can adapt to human-affected forest areas where large trees remain, and a recent study suggests that the population may be considerably larger than previously feared. Given this new evidence this species has been downlisted to Endangered, though it is still considered to have a small population which is likely to be declining owing to continuing habitat destruction and degradation in its small range.
Surveys carried out in 2010-2011 suggested that the species may be more widespread than previously thought, and frequent in degraded forest, with habitat modelling giving a potential range of 93.4 km2. Density was estimated at 0.53 birds per hectare (0.44-0.63, 95% CI), meaning that the total population possibly may be as high as 4,950 individuals (3,641-6,632, 95% CI) (K. Green in litt. 2010, 2011, Lloyd 2010). A recently published paper that collected data in 2010-2011 estimated the population at 3,466 individuals (2,654-4,526, 95% CI) during the dry season and 5,464 in the wet season (4,232-7,054, 95% CI) (Green et al. 2015) (rounded here to 3,500-5,500 individuals), which would roughly equate to 2,300-3,600 mature individuals.
It is suspected to be decreasing rapidly owing primarily to habitat clearance and perhaps also predation and competition from invasive species.
This species was rediscovered on Anjouan (= Ndzuani) in the Comoro Islands in June 1992, after an absence of records dating back to 1886. At least several tens of pairs, probably 100-200 pairs, were estimated to survive in 1999 (R. Safford in litt. 1999), and although a survey in 1995 produced a maximum estimate of only 96 individuals (Moorcroft 1996), differences between these two estimates may be due to sampling techniques. Surveys in 2006 found the bird to be abundant in suitable habitat and encouragingly found individuals in degraded habitats down to 300 m, and it has also been sighted at sea level (H. Doulton in litt. 2006, 2010, C. Marsh in litt. 2007, 2009). This survey estimated the population to be somewhere between the two previous estimates at 50-100 pairs (C. Marsh in litt. 2007, 2009).
Surveys carried out in 2010-2011 suggested that the species may be frequent in degraded forest (Green et al. 2015). Density was estimated at 0.53 birds per hectare (0.44-0.63, 95% CI), meaning that the total population may be significantly higher than previously thought and possibly as high as 4,950 individuals (3,641-6,632, 95% CI) (K. Green in litt. 2010, 2011, Lloyd 2010). Field surveys from May-July 2010 (dry season) and November 2010-April 2011 (wet season) estimated the population at 3,466 individuals (2,654-4,526, 95% CI) during the dry season and 5,464 individuals (4,232-7,054, 95% CI) in the wet season (Green et al. 2015). Densities were estimated at 0.55 individuals ha-1 (0.42-0.72, 95% CI) and 0.87 individuals ha-1 (0.67-1.12, 95% CI) for the dry and wet seasons respectively. Tracewski et al. (2016) estimated the maximum Area of Occupancy (calculated as the remaining tree area within the species’s range) to be c.166 km2, rounded here to 170 km2, though targeted habitat modelling instead gives a potential range of 63 km2 (Green et al. 2015).
It survives in remaining fragments of native upland forest, degraded forest and plantations, and appears to be dependent on large trees with cavities for nesting and roosting, usually on steep slopes (Safford 1993). Surveys in 2010-2011 found the species to be commonest in native forest, with significantly lower densities in degraded forest and lower densities still in plantations, and it also occurs in agroforestry with natural or non-natural understorey vegetation (K. Green in litt. 2011, Green et al. 2015). It has been recorded perching in thick cover, 3-15 m from the ground (Lewis 1996) and roosting 3-4 m off the ground on the bottom branch of a tree fern (H. Doulton in litt. 2006, 2010). Insects are believed to form at least part of its diet (Safford 1993). It is thought to breed between August and December, during the wet season (Green et al. 2015).
Habitat clearance for agriculture, timber extraction and charcoal manufacture is ongoing (Lewis 1996, Safford 2001, K. Green in litt. 2010). Between 1990-2000 the country suffered from the fourth highest rate of deforestation in the world. Remaining habitat is becoming increasingly degraded through human disturbance and invasion by exotic plants such as Rubus rosifolius and Lantana camara (Safford 1993). Introduced Black Rat Rattus rattus is abundant in the forest, and may predate nests (Safford 1993). The introduced Common Myna Acridotheres tristis may compete for nest holes (Safford 1993, H. Doulton in litt. 2006, 2010, C. Marsh in litt. 2007, 2009). Severe cyclones are a regular threat to remaining forest fragments (Safford 2001).
Conservation Actions Underway
CITES Appendix II. Long-term, ongoing developments that will benefit wildlife in general include a family-planning programme, environmental education projects, and the formation of a non-governmental environmental organisation (Ulanga) (Safford 1993). The UNDP, in partnership with the government, planned to implement a large-scale reserve covering Mount Ntingrui from around 2009. The creation of a protected area network for the Comoros Islands is still ongoing, with the Moya Forest in addition to Mount Ntingrui proposed as potential areas for protection (Green et al. 2015). A participatory conservation project has been ongoing on Anjouan since 2008 (H. Doulton in litt. 2006, 2010, K. Green in litt. 2010). Activities centre on improving livelihoods and agricultural productivity, helping communities to collectively manage their natural resources such as water, and monitoring biodiversity patterns across all three islands to help prioritise areas for wildlife protection. Bristol Conservation and Science Foundation’s (BCSF) project in the Comoros, Engagement Communautaire pour le Developpement Durable (ECDD) is taking a community-led landscape management approach towards the protection of forest and biodiversity in the Moya Forest region of Anjouan. Actions include intensification of agricultural practices to reduce the demand for land, improving soil fertility through terracing and the integration of livestock management into agricultural practices, and the development of alternative revenue streams such as through market gardening (K. Green, H. Doulton and B. Daniel in litt. 2012). Research aiming to establish a long-term monitoring scheme and recommend conservation actions to assist the preservation of the species began in 2010 (K. Green in litt. 2010, 2011).
Conservation Actions Proposed
Continue monitoring to confirm the population size, and carry out additional research on the ecology and behaviour of the species, including researching its requirements for food resources and nest sites, thus investigating why this species appears to be dependent on forested areas and has low presence in plantations. Although it has been found to be less dependent on pristine forest than previously feared, the species occurs at its highest densities in undisturbed forest, and conservation measures proposed should thus focus on the conservation of forest ecosystems, complemented with awareness raising for the species both nationally and internationally. Additional measures such as the provision of nest-boxes in secondary forest (Moorcroft 1996) and establishing a captive population as insurance against extinction (Safford 1993) may not be necessary if the species is confirmed to have a much larger population than was once suspected.
20-22 cm. Small, eared, dark-coloured owl. Two colour forms; both are barred, streaked and vermiculated: one is dark ashy-brown and the other paler rufous-brown with pale grey facial disc bordered black. Both frequently seen together. Voice Distinct, drawn-out whistle, often repeated and separated by short interludes.
Text account compilers
Bird, J., Butchart, S., Calvert, R., Ekstrom, J., Pilgrim, J., Shutes, S., Symes, A., Warren, B., Ashpole, J & Westrip, J.
Doulton, H., Green, K., Marsh, C., Safford, R., Daniel, B. & Louette, M.
BirdLife International (2021) Species factsheet: Otus capnodes. Downloaded from http://www.birdlife.org on 06/12/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 06/12/2021.