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Otus insularis
– Endangered
Taxonomy
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Kingdom:
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ANIMALIA
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Phylum:
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CHORDATA
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Class:
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AVES
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Order:
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STRIGIFORMES
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Family:
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STRIGIDAE
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Scientific Name:
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Otus insularis
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Species Authority:
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(Tristram, 1880)
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Synonym/s:
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Otus magicus ssp. insularis (Tristram, 1880)
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Common Name/s:
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| English | — | SEYCHELLES SCOPS-OWL |
| French | — | PETIT-DUC SCIEUR |
| Spanish | — | AUTILLO DE SEYCHELLES |
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Taxonomic Notes:
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Otus magicus (Sibley and Monroe 1990, 1993) has been split into O. alfredi following Widodo et al. (1999), O. siaoensis following Lambert and Rasmussen (1998), O. enganensis following Andrew (1992), O. insularis and O. beccarii following Holt et al. (1999) and O. magicus (with species limits accordingly revised).
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Assessment Information
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Red List Category & Criteria:
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EN D ver 3.1 (2001)
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Year Assessed:
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2004
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Assessor/s:
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BirdLife International
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Evaluator/s:
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Stattersfield, A., Ekstrom, J. & Butchart, S. (BirdLife International Red List Authority)
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Justification:
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This species has been downlisted to Endangered because there is new evidence that its extremely small population is stable and possibly increasing. Upland forests have increased in extent over the last 40 years due to re-growth of forests following long-term reduction of the cinnamon, coconut and logging industries. However, the species has an extremely small population that is susceptible to stochastic events and the effects of introduced taxa.
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History:
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| 1988 | - | Threatened (Collar and Andrew 1988) |
| 1994 | - | Critically Endangered (Collar, Crosby and Stattersfield 1994) |
| 2000 | - | Critically Endangered (BirdLife International 2000) |
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Geographic Range
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Range Description:
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Otus insularis is endemic to Mahé in the Seychelles. In 1996, it was recorded from previously unsurveyed areas, extending its known range into the extreme north of the Morne Seychellois National Park2. Recent research has refined the population estimate to 124-159 territories (c. 400 individuals) over a 31-33 km² range13. This population may have been more or less stable since the mid-1970s5,11 or it may have been slowly decreasing.
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Countries:
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Native:
Seychelles
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Population
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Population Trend:
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Habitat and Ecology
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Habitat and Ecology:
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It favours upland (>400 m), often mist-shrouded, mixed forest generally in areas of high rainfall5 in valleys and on sheltered slopes. Its previously supposed association with 'boulder fields' is now regarded as ecological meaningless because of the ubiquitous nature of such terrain13. Between 250 and 600 m it also inhabits secondary forest dominated by exotics2. Territories are 20-25 ha. It has been observed from low in the understorey up to the lower canopy2. Main prey items discovered from pellet analysis were Orthoptera, Coleoptera and Araneae, but no vertebrates13.
Eight nests have been found by scientists, all in two tree species Dillenia ferruginea and Pterocarpus indicus at heights of 7-25 m13. Nests may be found within wooded areas made up mainly of exotic vegetation12. A single egg is laid; scops owl normally lay two but Seychelles land birds characteristically lay a single egg13. Incubation and nestling periods are reportedly both of about one month, there may be two breeding seasons each year, and pairs can initiate renesting soon after nest failure13. Breeding success was low, c.0.5 fledglings/territory/year13.
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System:
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Terrestrial
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List of Habitats:
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| 1.6 | Forest - Subtropical/Tropical Moist Lowland |
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Threats
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Threats:
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Some lowland habitat destruction is occurring due to housing development5, and highland forest on Mahé continues to be cleared on a small scale for timber and tea cultivation (but these activities are not threats, providing they are not intensified)5,9. Promotion of ecotourism in the uplands, resulting in the creation of new trails and increased disturbance, may be a threat8. Introduced species including rats, cats and Barn Owl Tyto alba are likely predators of nests and adults5,9. Black Rat Rattus rattus is very likely to have predated two of the few nests so far discovered for this species12,13.
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List of Threats:
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| 1.1.3 | Habitat Loss/Degradation - Agriculture - Non-timber plantations (ongoing) |
| 1.3.3.3 | Habitat Loss/Degradation - Extraction - Wood - Clear-cutting (ongoing) |
| 1.4.1 | Habitat Loss/Degradation - Infrastructure development - Industry (ongoing) |
| 2.2 | Invasive alien species (directly affecting the species) - Predators (ongoing) |
| 5.2 | Persecution - Other (ongoing) |
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Conservation Actions
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Conservation Actions:
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Conservation measures underway:
CITES Appendix II. The species is protected by law in Seychelles under the Animals and Bird Protection Act13. Much of the highland forest where the species occurs is incorporated into the Morne Seychellois National Park (MSNP). A second protected area of 1000 ha south of the MSNP would protect 80% of the owl's range13. Some other sites are also classified as Sensitive Areas under the Environment Protection Act4. Survey work and a detailed monitoring programme are currently in progress5,7. A programme is underway to assess suitable islands to which future translocations could be considered8. A stakeholder agreed action plan recently highlighted key conservation management priorities for this species13. Importantly, there appear to be few realistic options for increasing its range on Mahé and few options to succeed in translocation programmes, given that the most suitable island (Silhouette) can hold only 20 territories and hosts a suite of alien predators13.
Conservation measures proposed:
Improve management of the Morne Seychellois National Park (MSNP), including implementation of a management plan, control of development, monitoring of ecotourism impacts, new legislation, enhanced institutional capacity, and a review of park boundaries1,8. Zone MSNP into seven areas of environmental sensitivity to limit disturbance to certain areas and protect the most important habitat above 400 m13. Examine the influence of alien predators on nest success and adult survivorship. Conduct a public awareness campaign to gain better knowledge of the species's occurrence4. Continue survey work to determine its distribution on Mahé, so that population densities can be monitored5. Continue ecological research, particularly into feeding and nesting requirements1.
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List of Conservation Actions:
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| 1.1.2 | Policy-based actions - Management plans - Implementation (needed) |
| 2.2 | Communication and Education - Awareness (needed) |
| 3.2 | Research actions - Population numbers and range (needed) |
| 3.3 | Research actions - Biology and Ecology (needed) |
| 3.9 | Research actions - Trends/Monitoring (needed) |
| 4.4.3 | Habitat and site-based actions - Protected areas - Management (needed) |
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Bibliography
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Bibliography:
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Baillie, J. and Groombridge, B. (compilers and editors) 1996. 1996 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland. Bird Reference Citations. The numbers inserted in the text accounts above (usually in bold) refer to references. For further details on these references, click on the BirdLife International link above to go to the specific species account on the BirdLife web site. In some cases, particularly in the taxonomic notes, the references are cited using the author names. Details for these can be found on the BirdLife International web site at the following two places:
For References from A–L.
For References from M–Z. BirdLife International. 2000. Threatened Birds of the World. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, U.K. BirdLife International. 2004 Threatened Birds of the World 2004. CD-ROM. BirdLife International, Cambridge, U.K. Collar, N.J. and Andrew, P. 1988. Birds to Watch. The ICBP World Checklist of Threatened Birds. ICBP Technical Publication No. 8. Page Bros. (Norwich) Ltd, Norfolk, England. Collar, N.J., Crosby, M.J. and Stattersfield, A.J. 1994. Birds to Watch 2. The World List of Threatened Birds BirdLife International. Page Bros (Norwich) Ltd, U.K. IUCN Conservation Monitoring Centre. 1986. 1986 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and Cambridge, UK. IUCN. 1990. 1990 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and Cambridge, UK.
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