Data Zone
Justification of Red List category
Ninox rotiensis is confined to a single island in the Lesser Sundas, Indonesia, where it has a small range and probably a smaller population size. Information is lacking on how ongoing slow rates of deforestation are impacting it, but it is suspected to be causing ongoing declines. Accordingly, it is listed as Near Threatened, although many knowledge gaps remain for this enigmatic species.
Population justification
The population size of this species has not been robustly estimated. It is descriptively considered local and uncommon (Verbelen et al. 2017, Eaton et al. 2021), and Verbelen et al. (2017) speculated there may be fewer than 500 mature individuals, writing that the population occurs in 'an area of less than 50–100 km2. However, the species appears to occur in several areas of forest across Rote (mostly in the north; eBird 2023), and the total area of suitable habitat is calculated here to be at least 200 km2. Verbelen et al.'s (2017) observation of six calling individuals in a relatively small area of evergreen forest near Bolatena suggests that, where good habitat remains, this species can occur at reasonably high density (as is often typical for insular Ninox). Precautionarily, the minimum number of mature individuals is set to 500. In the absence of specific data, the maximum number is set to 5,000 mature individuals, allowing for a total area of occupied habitat of c. 250 km2, and a density of 20 mature individuals or 10 pairs per km2.
Trend justification
It is suspected to be declining slowly in response to forest cover loss. N. rotiensis is at least moderately forest-dependent, being observed only very rarely in plantations or heavily degraded landscapes (Verbelen 2010, Verbelen et al. 2017, Eaton et al. 2021, eBird 2023). There is no other threat known or suspected to be impacting the species, thus the rate of population decline is thought to be closely matched to that of forest cover loss. Over the past three generations (16.35 years: 2007–2023), the rate of forest cover loss in its range was equal to 5–6%, depending on the assumptions used (Global Forest Watch 2023, based on data from Hansen et al. (2013) and methods disclosed therein). This rate accelerated slightly from 2014, equivalent to 7.5–9% over three generations. Over the past three generations therefore, the population size of this species is suspected to have declined by 1–9%, while over the next three generations (2023–2039), and in the window 2014–2030, the population is suspected to decline by a slightly increased rate of 3–13%. Because this species is tolerant of secondary forests, these declines are thought to be reversible if logging ceases.
The species is endemic to Rote (Roti), off south-west Timor, Nusa Tenggara (Lesser Sundas), Indonesia.
Of the trio of species recently split from N. boobook (N. fusca and N. plesseni being the other two), N. rotiensis is the most dependent on good forest (J. Eaton in litt. 2023), occurring only rarely in plantations (Verbelen 2010), with almost all records from forest (both primary and secondary) (Verbelen et al. 2017, Eaton et al. 2021, eBird 2023). On Rote, this habitat now occupies c. 25% of the island (per Global Forest Watch 2023).
The only threat to this forest-dependent species is habitat loss and degradation, which is thought to be causing moderate population declines equivalent to 1-9% over three generations. The main drivers of this forest loss are encroaching agriculture, small-holder farming and, to a lesser extent, localised plantations.
Conservations Actions Underway
None is known, and none of this species' range is contained within a protected area.
Conservation Actions Needed
A number of research questions need answering for this species. Among the most critical relate to quantifying its population size (which currently spans an order of magnitude, with a lower bound which could mean it is highly threatened) and trend. Its habitat tolerances, particularly in relation to breeding, also need elucidation. Rates of habitat conversion should continue to be monitored using remote sensing data (e.g. Global Forest Watch 2023). Remaining areas of forest that host this species should be considered a high priority and urgently need protecting; community engagement will be essential for effectively implementing this.
Similar to other members of the erstwhile Southern Boobook Ninox boobook sensu lato complex, from which recently split, principally on bioacoustic and genetic grounds (Gwee et al. 2017), with only minor differences in plumage (Eaton et al. 2021). Most similar to geographically closest N. fusca, but breat streaking denser and more rufous tone to the head and well-defined barring on tail. Best distinguished from other Ninox by vocalisations: a deep, croaky two-note 'crok-crok' lasting c. 0.5 seconds (Eaton et al. 2021).
Text account compilers
Berryman, A.
Contributors
Eaton, J.
Recommended citation
BirdLife International (2024) Species factsheet: Rote Boobook Ninox rotiensis. Downloaded from
https://datazone.birdlife.org/species/factsheet/rote-boobook-ninox-rotiensis on 20/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 20/12/2024.