VU
Sao Tome Scops-owl Otus hartlaubi



Justification

Justification of Red List Category
This species qualifies as Vulnerable because it is thought to have a small population, given the small area of suitable primary and mature secondary forest habitat within its range. Habitat degradation may be causing declines, and any stronger information to back this up could lead to the species being uplisted in the future.

Population justification
The population is estimated to number 250-999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.

Trend justification
The population is tentatively suspected to be declining as a result of ongoing habitat degradation.

Distribution and population

Otus hartlaubi is endemic to São Tomé, São Tomé e Príncipe, where it is relatively widely distributed in suitable habitat (Atkinson et al. 1991, Christy and Clarke 1998). It probably has a population of several hundred birds. Reports of a small owl on Príncipe could refer to this species, but recent searches have found no evidence of its presence (J. Baillie and A. Gascoigne in litt. 2000).

Ecology

It occurs in primary and undisturbed secondary forest up to 1,500 m, but not in plantations with shade trees. The diet includes invertebrates and probably small lizards. It calls frequently at dusk or dawn and occasionally during the day (Atkinson et al. 1991, Christy and Clarke 1998).

Threats

Historically, large areas of forest were cleared for coffee and cocoa plantations. Today, land privatisation is leading to an increase in the number of small farms and the clearance of trees. This does not currently affect primary forest but may be a threat in the future (A. Gascoigne in litt. 2000). Limited areas of primary and secondary forest, particularly in the north of the range, are threatened by clearance for cultivation, timber and fuelwood-collection (Atkinson et al. 1991). Road developments along the east and west coasts are increasing access to previously remote areas (A. Gascoigne in litt. 2000). Construction for the country's developing oil industry, including the established idea of building 'free ports' (free economic zones), was seen as a potential threat to the species's habitat (M. Melo in litt. 2003). However, prospecting on land was unsuccessful, and any construction is likely to be offshore (F. Olmos in litt. 2007).

Conservation actions

Conservation Actions Underway
CITES Appendix II. A new law providing for the gazetting of protected areas and the protection of threatened species has been ratified (A. Gascoigne in litt. 2000, M. Melo in litt. 2003, F. Olmos in litt. 2007). Legislation for the creation of Obo National Park has also been ratified (F. Olmos in litt. 2007) and protection of primary forest as a zona ecologica has been proposed.

Conservation Actions Proposed
Research its ecological requirements. Carry out surveys to establish its population size and distribution. Identify the key threats in order to produce conservation recommendations. Ensure legal protection of all remaining primary forest and maintain areas of mature secondary forest where it occurs. List it as a protected species under national law.

Identification

16-19 cm. Small, unobtrusive owl with tiny ear-tufts. Light rufous-brown facial disc with white chin and eyebrows. Warm rufous-brown crown and upperparts with rufous vermiculations and black shaft streaks. Black-tipped white spots on scapulars. Buff and white mottling on flight feathers and narrow buff bars on tail. Finely vermiculated white, brown and rufous underparts with bold black streaking. Juvenile paler. Voice Hooting whistle hu-hu-hu and growling urrrr.

Acknowledgements

Text account compilers
Robertson, P., Starkey, M., Peet, N., Symes, A., Ekstrom, J., Taylor, J., Westrip, J.

Contributors
Olmos, F., Melo, M., Baillie, J., Gascoigne, A.


Recommended citation
BirdLife International (2019) Species factsheet: Otus hartlaubi. Downloaded from http://www.birdlife.org on 24/06/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/06/2019.