Justification of Red List Category
This recently rediscovered and little-known species is listed as Data Deficient because there is insufficient information available for a robust assessment of its extinction risk against the Red List criteria.
The population size has not been quantified and further research is required.
The population trend has not been quantified and further research is required to assess this and potential threats to the species.
When Hume described Strix butleri in 1878, he used a type specimen from the Mekran coast of southwestern Pakistan. When an owl with unknown vocalisations and a plumage different from the prevailing concept of S butleri was discovered in 2013 in northern Oman, it was initially described as a new species, S omanensis (Robb et al. 2013). Soon afterwards, however, Kirwan et al. (2015) showed that all specimens of ‘butleri’ other than the type specimen were in fact a distinct and previously undescribed species, which they named S. hadorami. The owl discovered in northern Oman subsequently prove to be a genetic match for S. butleri sensu strictu (Robb et al. 2016).
In Oman the species has so far only been found in the northern foothills of Al Jabal Al Akhdar, in the central part of the Al Hajar mountains (Robb et al. 2013). Following this discovery there followed the subsequent publication of a putative record c.33 km away dating from 2008 (van Eijk 2013). In the vicinity of the original discovery site in Oman, six or seven individuals have been found, including at least two pairs, along a c.3-km stretch of wadi (Robb et al. 2013). Given that similar habitat exists in other unsurveyed wadis near the original rediscovery site, it is thought likely that the species will be found elsewhere in the Al Hajar mountains. A preliminary survey in 2015 in Al Jabal Al Akhdar detected a minimum of 15 territories (van Eijk 2013, Robb et al. 2013, Robb et al. 2015).
All known territories in Oman are in precipitous terrain with massive cliffs, not less than 400 m above sea level. However a male was recently detected in Wadi Wurayah National Park, Fujaira, United Arab Emirates, an area with much smaller cliffs, 150-350 m above sea level (Judas et al. 2015). Since January 2015, the species has also been photographed in three provinces of Iran: Bushehr in the south-west, Khorasan-e Razavi in the north-east and Yazd in the centre (Musavi et al. 2016, S.B. Musavi in litt. to M. Robb in litt. 2016). It remains unknown whether the species still occurs in Pakistan. Given the scatter of records across an area spanning 1,450 km, it seems likely that the population size is considerably greater than current knowledge suggests.
The species’s ecology may render it very rare, but for now the population size remains a matter of speculation (Robb et al. 2013).
This species was rediscovered along a wadi with scattered trees, surrounded by cliffs and steep mountain slopes, in the foothills of the Al Hajar mountains, and may require cliffs for nesting (Robb et al. 2013).
There is apparently no information available on potential threats to this little-known species.
Conservation Actions Underway
The species's known range in the United Arab Emirates is protected within a national park (Judas et al. 2015).
Conservation Actions Proposed
Carry out further surveys to search for more populations and assess the total population size. Conduct research into the species's ecology and habitat requirements. Study potential threats to the species.
Text account compilers
Ashpole, J, Symes, A., Taylor, J.
Robb, M., van Eijk, P., Porter, R.
BirdLife International (2018) Species factsheet: Strix butleri. Downloaded from http://www.birdlife.org on 19/11/2018. Recommended citation for factsheets for more than one species: BirdLife International (2018) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/11/2018.