EN
Grand Comoro Scops-owl Otus pauliani



Justification

Justification of Red List Category
This species is classified as Endangered since it has a very small range and population size, occurring at only one location, an active volcano where clearance of forest for agriculture by the island's large and increasing human population is causing a continuing decline in the area of suitable habitat, and thus its extent of occurrence, area of occupancy, and population.

Population justification
In November 1989, studies revealed its presence on the northern, western and southern flanks of the volcano where about 100 km2 of suitable habitat exists, and the population may prove to be over 1,000 pairs (Herremans et al. 1991a). In September 2005, the species was found to be abundant on the south-eastern flanks of the Karthala, which may increase the population estimate. However, no formal revised estimate is available and the extent of suitable habitat will have been reduced since 1989. The estimate is thus retained at 2,000 individuals, roughly equivalent to at least 1,300 mature individuals.

Trend justification
This species's population is suspected to be declining at a rate of 1-19% over ten years, in line with habitat loss and degradation within its range.

Distribution and population

Otus pauliani is found only on Mt Karthala, an active volcano on Grand Comoro (= Ngazidja), in the Comoro Islands. Tracewski et al. (2016) estimated the maximum Area of Occupancy (calculated as the remaining tree area within the species’s range) to be c.144 km2, rounded here to 140 km2.

Ecology

This species occurs from 650 m upwards to the tree line (Louette et al. 2008). It is territorial, occurring in primary, montane, evergreen forest, favouring areas with old hollow trees, but is also found in pioneer forest; (forest that grows on rocky soils [Louette et al. 1988, Louette et al. 1990]) and regenerating forest dominated by Psidium cattleianum (Safford 2001). although it is not clear whether it occurs in similar densities in such degraded habitat. It shows a preference for edge habitat: either edges along the upper limits of the forest where it is replaced by giant heath Philippia, edges along old lava-flows, or edges of open areas within the forest itself (Louette et al. 1988). Its feeding and breeding ecology are unknown.

Threats

Since 1983 intact forest may have declined by over 25% as agriculture, on all but the poorest soils, has advanced steadily up the slopes of Mt Karthala toward the habitat of O. pauliani (Safford 2001). There is large clearance for road construction on the western side above Mvouni, relatively intensive logging for plank production using chainsaws in the south, above Kourani, and cattle grazing on the Phillipia heaths in the highlands (K. Green in litt. 2012). Secondary forest in the agricultural belt on the mountain is dominated by exotic plants, particularly strawberry guava Psidium cattleianum (Safford 2001), which could spread into and degrade remaining native forest. Commercial logging occurs in a 50 km2 concession on the south-western slopes (Safford 2001). Pioneer forest, although unsuitable for agriculture and of little value for logging, is susceptible to fire and may be burnt to provide grassland for cattle (Louette et al. 1990). Grazing is increasing - even at high altitudes - and could prohibit forest regeneration (Louette and Stevens 1992, Louette et al. 1988). Introduced rats and Common Myna Acridotheres tristis may act as competitors or nest predators (Safford 2001). If plans to build a road to Mt Karthala's crater are resurrected, exploitation and fragmentation of the forest, and the spread of exotic species, could be accelerated (Safford 2001).

Conservation actions

Conservation Actions Underway
CITES Appendix II. A protected area (national park, biosphere reserve or resource management area) on Mt Karthala has been suggested, but has not yet materialised (Louette and Stevens 1992, Safford 2001). Protected area planning was underway for the Karthala forests in 2012 (K. Green in litt. 2012).

Conservation Actions Proposed
Research the ecology of this species to aid conservation plans. Create a protected area on Mt Karthala to encompass the remaining native forest, and develop a land-use strategy (Louette and Stevens 1992, Safford 2001). Encourage locally-organised ecotourism as an alternative source of income for inhabitants of the Mt Karthala area (Safford 2001). Develop an environmental education programme on the island (Louette and Stevens 1992).

Identification

20-22 cm. Small owl. Only one colour form: greyish-brown, heavily barred, streaked and vermiculated. Bright yellow eyes. Voice Whistled toot given at one-second intervals.

Acknowledgements

Text account compilers
Bird, J., Butchart, S., Ekstrom, J., Pilgrim, J., Shutes, S., Symes, A., Warren, B., Ashpole, J & Westrip, J.

Contributors
Louette, M., Marsh, C., Green, K., Safford, R. & Doulton, H.


Recommended citation
BirdLife International (2019) Species factsheet: Otus pauliani. Downloaded from http://www.birdlife.org on 25/03/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 25/03/2019.