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Sokoke Scops-owl Otus ireneae
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Justification
This owl is listed as Endangered because it has a very small, severely fragmented range, within which its population and the quality of its habitat is declining. In Tanzania the owl inhabits a coastal forest that, while still extensive, is under some pressure from fires, encroachment and tree-cutting.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Identification
15 cm. Very small owl with slight "ears". Both grey and rufous forms occur. Heavily barred, streaked and vermiculated like most scops-owls Otus spp. Similar spp. African Barred Owlet Glaucidium capense much bigger with obviously barred, not vermiculated, underparts. Voice Soft too too too, repeated 10 or more times per minute. Hints At day-roost in thicket, usually in pairs, compresses body and holds ears erect and eyes drawn closed to slits. Most easily located in the Cynometra woodland of Arabuko-Sokoke Forest between Kilifi and Malindi on the Kenya coast. It feeds on insects, mainly beetles.

Distribution and population
Otus ireneae was believed to be endemic to the Arabuko-Sokoke Forest in coastal Kenya, but in 1992 it was found in the lowlands of the East Usambara Mountains of Tanzania as well (Evans 1997a). In Arabuko-Sokoke, a population of c.1,000 pairs occurs in c.220 km2 of forest (Virani 1995b) - this population was suspected to have been stable between 1984 and 1998 (Virani 2000a), but playback surveys in 2005 and 2008, and compared with data from 1993, suggest that the species may have undergone declines of 22.5 % in 16 years (Virani et al. 2010). In the East Usambaras, there are c.97 km2 of suitable habitat and densities range from less than 1.5 pairs/km2 up to 3-4 pairs/km2, suggesting a population in the low hundreds (Evans 1997b). The species might also occur in the Mundane Range, near the Kenya-Somalia border (Virani 1995a, 1995b). The discovery of a very small population on the edge of Marafa Forest to the north of Arabuko-Sokoke suggests further exploration of the overall area might produce more pockets of habitat holding marginal or remnant populations (C. Jackson in litt. 2004), and this may possibly be true for the lowland areas of the East Usambaras (N. Burgess in litt. 2007), although it was not found at three previously unsurveyed Brachylaena woodland sites in north-east Tanzania (Cordeiro & Githiru 2000). Surveys in Kaya forests along the Kenyan coast south of Mombasa did not locate the species (M. Virani in litt. 2007).


Population justification
In Arabuko-Sokoke, a population of c.1,000 pairs (stable between 1984 and 1998) occurs in c.220 km2 of forest. In the East Usambaras, there are c.97 km2 of suitable habitat and densities range from less than 1.5 pairs/km2 up to 3-4 pairs/km2, suggesting a population in the low hundreds. The total population is estimated to number at least 2,500 individuals and is placed in the band 2,500-9,999 mature individuals. This equates to 3,750-14,999 individuals in total, rounded here to 3,500-15,000 individuals.

Trend justification
This species's population is suspected to be declining in line with habitat degradation within its range. Unsustainable removal of large Brachylaena trees, which were thought to be its main resource for nest-cavities, was suspected to be critical, but there may now be few if any of these trees remaining in Arabuko-Sokoke. Playback surveys in 2005 and 2008, and compared with data from 1993, suggest that the species may have undergone declines of 22.5 % in 16 years in Arabuko-Sokoke (Virani et al. 2010).The likely overall rate of population decline over three generations has not been estimated.

Ecology
In Arabuko-Sokoke, it occurs mostly in good quality Cynometra forest (787 pairs in 99 km2), and at much lower densities in an additional 120 km2 of secondary or more disturbed Cynometra forest (Virani 1995b, Evans 1997b). It roosts and forages in the dense lower half of the Cynometra canopy and possibly nests in natural cavities in large or old Brachylaena trees (Virani 1994, 1995b). It feeds mainly on beetles (Cameron 2003), with 91 % of the diet in one study in Arabuko-Sokoke found to consist of Coleoptera (Virani 2008). In the East Usambaras it occurs in lowland coastal forest with a mixed tree species composition up to 400 m which is taller and structurally different to that in Arabuko-Sokoke (Evans 1997b, N. Burgess in litt. 2007). It has a home range of 12-14 ha (Virani 1995b, 2000b).

Threats
In Arabuko-Sokoke, unsustainable (and often illegal) extraction of Brachylaena huillensis for wood-carving and firewood may have reduced the species's breeding success (Virani 1995b, M. Z. A. Virani in litt. 1999), and there may now be few if any of these trees remaining (N. Burgess in litt. 2012). O. ireneae is probably long-lived (Cameron 2003), so the resulting declines might not be observed for some time. In the East Usambaras, most lowland forest outside reserves has already been cleared for agriculture, and there is a programme to reserve the remaining patches as village forest reserves (N. Burgess in litt. 2007, 2012). Government-owned forest reserves suffer from pit-sawing of timber and pole-cutting (Evans et al. 1994, N. Burgess in litt. 2007). In addition, Arabuko-Sokoke forest is under threat from titanium mining (Cameron 2003, N. Burgess in litt. 2007). It is possible that the species breeds opportunistically in response to rain, however the seasons in Kenya have deteriorated into more irregular rains and increased droughts (Cameron 2003).

Conservation Actions Underway
CITES Appendix II. Arabuko-Sokoke Forest is the focus of a project aiming to promote long-term conservation through community management (Fanshawe 1997). Within the forest reserve there is a 43-km2 strict nature reserve, although this does not contain good quality owl habitat (Virani 1995a, 1995b, 2000a, N. Burgess in litt. 2007). A two-yearly census of the owls in Arabuko-Sokoke was initiated (M. Z. A. Virani in litt. 1999). The Peregrine Fund has been funding the study of the species in Arabuko-Sokoke Forest, including the radio-tracking of birds (Cameron 2003). In the East Usambaras, the main habitat is found in the Kwamgumi-Bamba-Segoma forest reserves, and also in the lowland forests within the private Kwamtili estate (N. Burgess in litt. 2007). Efforts were started to link all of these forest areas together within a single forest reserve managed by the central government, but this has not been concluded and additional support is needed to complete the process (N. Burgess in litt. 2007, 2012). Conservation Actions Proposed
Study its breeding biology, population structure, survival, and habitat requirements (Virani et al. 2010). Study the effects of removing Brachylaena. Monitor populations and forest health in Arabuko-Sokoke, Dakatcha and Usambara forests. Evaluate the effectiveness of nest-boxes as substitute breeding sites (L. Bennun in litt. 1999). Survey additional lowland forest reserves, village forests, and unprotected forest patches in the East Usambaras, as well as Brachylaena-Cynometra woodland in the Mwakijembe area of north-eastern Tanzania, and, in Kenya, north of Dakatcha as far as the southern coast of Somalia to see whether they hold the species (M. Z. A. Virani in litt. 1999, N. Burgess in litt. 2007, N. Cordeiro in litt. 2007, Virani et al. 2010). Increase the area of suitable habitat that has protected status. Continue to work towards linking existing reserves into a single forest reserve in the lowland East Usambaras.


References
Cameron, A. 2003. Tracking time Sokoke Scops Owl. Africa - Birds & Birding: 44-50.

Collar, N. J.; Stuart, S. N. 1985. Threatened birds of Africa and related islands: the ICBP/IUCN Red Data Book. International Council for Bird Preservation, and International Union for Conservation of Nature and Natural Resources, Cambridge, U.K.

Cordeiro, N. J.; Githiru, M. 2000. Conservation evaluation for birds of Brachylaena woodland and mixed dry forest in north-east Tanzania. Bird Conservation International 10: 47-65.

Evans, T. D. 1997. Preliminary estimates of the population density of the Sokoke Scops Owl Otus ireneae Ripley in the East Usambara lowlands, Tanzania. African Journal of Ecology 35: 303-311.

Evans, T. D. 1997. Records of birds from the forests of the East Usambara lowlands, Tanzania, August 1994 - February 1995. Scopus 19: 92-108.

Evans, T. D.; Watson, L. G.; Hipkiss, A. J.; Kiure, J.; Timmins, R. J.; Perkin, A. W. 1994. New records of Sokoke Scops Owl Otus ireneae, Usambara Eagle Owl Bubo vosseleri and East Coast Akalat Sheppardia gunningi from Tanzania. Scopus 18: 40-7.

Fanshawe, J. 1997. Second Annual Report of the Arabuko-Sokoke Forest Management and Conservation Project to the European Commission.

Hall, J.; Burgess, N.D.; Lovett, J.; Mbilinyi, B.; Gereau, R.E. 2009. Conservation implications of deforestation across an elevational gradient in the Eastern Arc Mountains, Tanzania. Biological Conservation 142: 2510-2521.

Virani, M. 1995. Sokoke Scops Owl in Tanzania. Swara 18: 34.

Virani, M. 1995. Who gives a hoot? Swara 18: 18-21.

Virani, M. 2000. Distribution and population size of the Sokoke Scops Owl Otus ireneae in the Arabuko-Sokoke Forest, Kenya. In: Chancellor, R.D.; Meyburg, B.-U. (ed.), Raptors at risk. Proceedings of the fifth world conference on birds of prey and owls. Midrand, Johannesburg, South Africa, 4-11 August 1998, pp. 795-801. Hancock House, Surrey, Canada.

Virani, M. 2000. Home range and movement patterns of Sokoke Scops Owl Otus ireneae. Ostrich 71: 139-142.

Virani, M. Z. 2008. Diet composition of Sokoke Scops Owl Otus ireneae in Arabuko-Sokoke Forest. Scopus 27: 6-9.

Virani, M. Z. A. 1994. Ecology of the endangered Sokoke Scops Owl (Otus ireneae). Thesis. MSc, University of Leicester.

Virani, M. Z.; Njoroge, P.; Gordon, I. 2010. Disconcerting trends in populations of the endangered Sokoke Scops Owl Otus ireneae in the Arabuko-Sokoke Forest, Kenya. Ostrich 81(2): 155-158.

Further web sources of information
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Text account compilers
Ekstrom, J., Evans, M., Harding, M., Pilgrim, J., Shutes, S., Starkey, M., Symes, A., Taylor, J.

Contributors
Bennun, L., Burgess, N., Jackson, C., Kahemela, A., Kilahama, F., Nderumaki, M., Sawe, C., Virani, M., Cordeiro, N.

IUCN Red List evaluators
Butchart, S., Taylor, J.

Recommended citation
BirdLife International (2014) Species factsheet: Otus ireneae. Downloaded from http://www.birdlife.org on 31/07/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 31/07/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Sokoke scops-owl (Otus ireneae) 0

Key facts
Current IUCN Red List category Endangered
Family Strigidae (Typical Owls)
Species name author Ripley, 1966
Population size 2500-9999 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 640 km2
Country endemic? No
Links to further information
- Additional Information on this species