Seychelles Scops-Owl Otus insularis Scientific name definitions

c. 20 cm. Resembles yellowish-brown or rufous morph of O. magicus, but smaller, and with minute ear-tufts (even in alert posture); differs further in unfeathered tarsus, often more buffish coloration, more prominent rim to facial disc, more distinct large black spots on crown and nape. Juvenile similar to adult, but recent fledgling has distinctive chest barring and fluffy appearance (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ).

Mahé I, in Seychelles. Unconfirmed reports also from Praslin and Félicité.

Virtually all records from secondary forest on upper slopes and in valleys, at 250–710 m (6 Currie, D., Millett, J., Hill, M. and Shah, N.J. (2002). Factors affecting the response of Seychelles Scops-owl Otus insularis to playback of conspecific calls: consequences for monitoring and management. Bird Conservation International. 12(4): 353-364. Close ) above sea-level, usually close to water source, and suitable habitat exists up to the summit of Morne Seychellois at 906 m; thought originally to have inhabited lowland forest and woodland as well, before these latter destroyed. Favours upland (>400 m) mixed forest with native and introduced trees and a high canopy, which is often mist-shrouded, and generally in areas of high rainfall also favoured by the endemic frogs (Tachycnemis seychellensis and Sooglossus spp.), in valleys and on sheltered slopes, sometimes in close proximity to urban and agricultural areas (7 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The distribution and population of the Seychelles (Bare-legged) Scops Owl Otus insularis on Mahé: consequences for conservation. Ibis. 146(1): 27-37. Close ). At 250–600 m it inhabits secondary forest, dominated by exotics, nesting in areas comprised primarily of Cinnamomum verum, with Paraserianthes falcataria and Sandoricum koetjape (8 Fanchette, R., Hoareau, C., Currie, D., Parr, S.J. and Shah, N.J. (2000). First nest record for the Seychelles (bare-legged) Scops Owl Otus insularis. Ibis. 142(3): 485-486. Close ).

Insects, tree-frogs and lizards (e.g. Scelotes gardineri) probably most important prey; stomach contents have included grasshoppers, beetles, lizards, and some vegetable matter. First detailed dietary study based on 400 prey items identified from pellets and video recordings of provisioning at two nests revealed that pellets comprised exclusively of invertebrate remains: Orthoptera (64%), Coleoptera (14%), arachnids (11%) and other invertebrates (11%), while 111 (76%) of all items identified during 145 provisioning visits were invertebrates of which 73 (66%) were identified to morphospecies and comprised Orthoptera (93%), arachnids (4%) and Lepidoptera (3%), with largest prey etimated at c. 5 cm in length (9 Currie, D., Hill, M., Vel, T., Fanchette, R. and Hoareau, C. (2003). Diet of the critically endangered Seychelles Scops Owl, Otus insularis. Ostrich. 74(3-4): 205-208. Close ). Strictly nocturnal, with prey apparently being taken on the ground, from foliage and on tree trunks (9 Currie, D., Hill, M., Vel, T., Fanchette, R. and Hoareau, C. (2003). Diet of the critically endangered Seychelles Scops Owl, Otus insularis. Ostrich. 74(3-4): 205-208. Close ).

Song  , more drawn-out and less grunting, with shorter intervals between calls than in O. magicus (10 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ), is a deep saw-like croak, “waugh”, repeated every 3–4 seconds, also series of knocking “tok tok tok” sounds, the two sometimes interspersed; sequence may last up to 20 minutes, given especially just after dusk and before dawn (6 Currie, D., Millett, J., Hill, M. and Shah, N.J. (2002). Factors affecting the response of Seychelles Scops-owl Otus insularis to playback of conspecific calls: consequences for monitoring and management. Bird Conservation International. 12(4): 353-364. Close ) and in Mar–Sept (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ). Both sexes can sing, but females probably do so less regularly (6 Currie, D., Millett, J., Hill, M. and Shah, N.J. (2002). Factors affecting the response of Seychelles Scops-owl Otus insularis to playback of conspecific calls: consequences for monitoring and management. Bird Conservation International. 12(4): 353-364. Close ). In addition to male–female duets, which consist of range of vocalizations
including frog- and duck-like calls (“quacking”), and gurgling calls (“arguing”) (6 Currie, D., Millett, J., Hill, M. and Shah, N.J. (2002). Factors affecting the response of Seychelles Scops-owl Otus insularis to playback of conspecific calls: consequences for monitoring and management. Bird Conservation International. 12(4): 353-364. Close ), males have also been recorded duetting with their own fledged young (6 Currie, D., Millett, J., Hill, M. and Shah, N.J. (2002). Factors affecting the response of Seychelles Scops-owl Otus insularis to playback of conspecific calls: consequences for monitoring and management. Bird Conservation International. 12(4): 353-364. Close ). Female frequently gives “squack” begging call during month prior to egg-laying, which prompts male to courtship feed her (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ) and younger juveniles utter a “whsst” call (6 Currie, D., Millett, J., Hill, M. and Shah, N.J. (2002). Factors affecting the response of Seychelles Scops-owl Otus insularis to playback of conspecific calls: consequences for monitoring and management. Bird Conservation International. 12(4): 353-364. Close ).

Until recently, data were few and sparse, and subject to much speculation. High-pitched whistle apparently given during copulation, heard frequently in Oct and Apr, and fledged young seen in Nov and Jun, while more recent data indicate this owl breeds year-round with peaks of activity in May and Nov, and at least occasionally breeds twice per annum (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ). That species favours boulder fields in forest and spends much time on ground led to suggestion that nests are subterranean, but this now known to be untrue. Nest in unlined cavity in tree (Dillenia ferruginea (8 Fanchette, R., Hoareau, C., Currie, D., Parr, S.J. and Shah, N.J. (2000). First nest record for the Seychelles (bare-legged) Scops Owl Otus insularis. Ibis. 142(3): 485-486. Close ) and Pterocarpus indicus) (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ), 7–25 m above ground (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ); first nest to be discovered had entrance 30 cm high, 15 cm wide, with cavity 7 cm deep (8 Fanchette, R., Hoareau, C., Currie, D., Parr, S.J. and Shah, N.J. (2000). First nest record for the Seychelles (bare-legged) Scops Owl Otus insularis. Ibis. 142(3): 485-486. Close ). Clutch size one white egg (8 Fanchette, R., Hoareau, C., Currie, D., Parr, S.J. and Shah, N.J. (2000). First nest record for the Seychelles (bare-legged) Scops Owl Otus insularis. Ibis. 142(3): 485-486. Close ), mean size 34·73 ± 0·49 mm × 29·3 ± 0·58 mm (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ), mass 15 g (8 Fanchette, R., Hoareau, C., Currie, D., Parr, S.J. and Shah, N.J. (2000). First nest record for the Seychelles (bare-legged) Scops Owl Otus insularis. Ibis. 142(3): 485-486. Close ); incubation by female alone (provisioned by male) for 21–28 days (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ); young, provisioned mainly by male for first two weeks at rate of 1·8 feeds/hour, thereafter rising to 2·4 feeds/hour, fledge at 28–42 days (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ) but are to some extent dependent for at least c. 3 months (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ) and may remain on adults’ territory well into next breeding season (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ). Nesting success apparently low, with just two of eight nests successful in one study (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ). Predation may be significant cause of nest failure, with suspected culprits at 2–3 nests being black rats (Rattus rattus) (8 Fanchette, R., Hoareau, C., Currie, D., Parr, S.J. and Shah, N.J. (2000). First nest record for the Seychelles (bare-legged) Scops Owl Otus insularis. Ibis. 142(3): 485-486. Close ), while eggs failed to hatch at another three nests (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ).

ENDANGERED. CITES II. Previously regarded as Critically Endangered. Restricted-range species: present in Granitic Seychelles EBA. Following its discovery in 1880, and despite a specimen collected in 1940, no others sighted for over half a century; declared extinct in 1958. Its rediscovery on Mahé in 1959 led to speculation that 20 birds may remain on the island; studies in mid 1970s confirmed presence of 12 pairs, extrapolation from which suggested total population of perhaps over 80 pairs, possibly twice that; in mid 1990s, preliminary estimate of 90–180 territories, of which some are as large as c. 57 ha (11 Currie, D., Fanchette, R. and Hoareau, C. (2001). The most enigmatic bird in Seychelles? - The Seychelles Scops Owl, Otus insularis. Ostrich. 72(2) (Suppl. 15): 199. Close ), but more recent research suggests that mean size is 12–16 ha (6 Currie, D., Millett, J., Hill, M. and Shah, N.J. (2002). Factors affecting the response of Seychelles Scops-owl Otus insularis to playback of conspecific calls: consequences for monitoring and management. Bird Conservation International. 12(4): 353-364. Close ) and survey in 2000–2001 suggested population of between 250 and 318 mature individuals (7 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The distribution and population of the Seychelles (Bare-legged) Scops Owl Otus insularis on Mahé: consequences for conservation. Ibis. 146(1): 27-37. Close ). No data on current population trend, but it is highly unlikely to be undergoing significant declines, as most available habitat is occupied and the area of habitat is probably stable. Earlier reports of possible presence on Praslin and nearby Félicité I unconfirmed. Some habitat destruction, at lower limit of species’ range, due to housing and other developments, and small-scale clearance of highland forest continues on Mahé for timber and tea cultivation, and localised clearance, e.g. for Cinnamomum verum coppicing and governmentral forestry activities may impact specific pairs, but if areas S of national park were developed the owl could suffer a severe reduction in population; promotion of ecotourism, resulting in new trails and increased disturbance, may be a localized threat, while in recent years Pterocarpus indicus has been decimated by a fungal disease leading to widespread local extinction and a drastic reduction in suitable nest-sites, climate change presents a long-term threat, probably through increased extreme weather events, such as storms, and the existence of just one island population means the species is vulnerable to catastrophic events. Some conservation measures already taken; Morne Seychellois National Park includes much of highland forest in its range, but extension of its boundaries desirable. Monitoring by means of controlled tape-luring can be used to determine distribution and status; more complete understanding of species’ ecology and biology, especially breeding habits, required before degree of threat can be assessed and conservation measures successfully implemented. Speculation that introduced Common Barn-owl (Tyto alba) may compete for food considered improbable, but may be predator of fledglings and adults, while other alien species that are potential nest and fledgling predators include rats (Rattus rattus and R. norvegicus) and domestic cats (Felix catus), and Common Myna (Acridotheres tristis) is a potential nest-site competitor (1 Currie, D., Fanchette, R., Millett, J., Hoareau, C. and Shah, N.J. (2004). The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management. Bird Conservation International. 14(2): 123-137. Close ).