Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 March 2025 | 17(3): 26753–26756
ISSN 0974-7907 (Online)
| ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.9052.17.3.26753-26756
#9052 | Received 30
March 2024 | Final received 16 February 2025 | Finally accepted 07 March 2025
New sighting and
conservation implications of the endemic Sulu Boobook Ninox
reyi Oustalet, 1880 at Bolobok Rock Shelter, a key archaeological site in the Sulu
Archipelago, southern Philippines
Fauriza J. Saddari 1 , Yennyriza T. Abduraup 2, Adzmer A. Juaini 3 , Roger A. Irilis
4 , Khalid D. Adam 5 , Mary Joyce Z. Guinto-Sali 6 & Richard N. Muallil
7
1–7 Mindanao State
University Tawi-Tawi College of Technology and
Oceanography, Bongao, Tawi Tawi 7500, Philippines.
1 faurizasaddari@msutawi-tawi.edu.ph,
2 yennyrizaabduraup@msutawi-tawi.edu.ph, 3 adzmerjuaini@msutawi-tawi.edu.ph,
4 rogeririlis@msutawi-tawi.edu.ph, 5 khalidadam@msutawi-tawi.edu.ph,
6 chancellor@msutawi-tawi.edu.ph, 7 rnmuallil@msutawi-tawi.edu.ph
(corresponding author)
Editor: Mário Gabriel Santiago dos Santos,
University of Trás-os-Montes
e Alto Douro, Portugal. Date of publication: 26 March 2025
(online & print)
Citation: Saddari, F.J., Y.T. Abduraup,
A.A. Juaini, R.A. Irilis,
K.D. Adam, M.J.Z. Guinto-Sali & R.N. Muallil (2025).
New sighting and conservation implications of the endemic Sulu Boobook Ninox reyi Oustalet, 1880 at Bolobok Rock
Shelter, a key archaeological site in the Sulu Archipelago, southern Philippines. Journal of Threatened Taxa 17(3): 26753–26756. https://doi.org/10.11609/jott.9052.17.3.26753-26756
Copyright: © Saddari et al. 2025. Creative Commons
Attribution 4.0 International License. JoTT allows
unrestricted use, reproduction, and distribution of this article in any medium
by providing adequate credit to the author(s) and the source of publication.
Funding: Department of Science and Technology – National Research Council of the Philippines.
Competing interests: The authors declare no competing interests.
Acknowledgements: This study is an output of MSU TCTO’s DOST-NRCP-funded project titled “Mainstreaming Islamic and Indigenous Knowledge and Practices for Sustainable Environmental Conservation and Climate Change Adaptation in Tawi-Tawi.” Gratitude is extended to all individuals who aided in the observation and documentation of this Sulu Boobook and to the local community for their efforts in preserving the natural environment of Bolobok Rock Shelter.
The Sulu Hawk-owl Ninox reyi, also
known as the Sulu Boobook, a member of the Strigidae
family, is endemic to the Sulu Archipelago in the southern Philippines.
Formerly classified as a subspecies of the Philippine Hawk-owl, it was
reclassified as a distinct species in 2012 based on distinctive vocalizations
and other evidence (Rasmussen et al. 2012). Kennedy et al. (2000) describes the
Sulu Boobook as a modestly-sized owl, standing 20 cm tall, which places it
between the larger Philippine Hawk-owl complex species and the smaller Luzon
& Mindanao Boobooks in terms of size. Its plumage is characterized by brown
stripes on the upper body, a warmer orange-brown hue on the underside, and
noticeable white spots on the wings. A white throat mark and pale
yellow eyes are its distinguishing traits. Unlike its congeners, the
Sulu Boobook’s call is a distinctive rattling sequence, not the usual hoots
associated with Philippine owls.
Scientific research
on Philippine Hawk-owls is generally scarce. Available studies indicate that
they typically inhabit tropical moist lowland primary and secondary forests up
to 700 m, and can also be found along forest edges, in glades, and on
plantations. For the Sulu Boobook in Tawi-Tawi, its
presence have been recorded in mature mangroves and
large trees near villages (Rasmussen et al. 2012). It has also been documented
in various places within Tawi-Tawi, such as Sibutu municipality, Bongao &
Sanga-Sanga islands in Bongao municipality, and Tarawakan, Balimbing, & Batu-Batu in Panglima Sugala municipality (Allen 2001; Rasmussen et al. 2012; BirdLife International 2016) (Figure 1).
Although initially
documented in the late 19th century, scientific data on the Sulu
Boobook remain limited (Allen 2001; van de Ven et al.
2019). The most recent comprehensive surveys in Tawi-Tawi,
which documented the Sulu Boobook in its natural habitat, were carried out by
Allen in the late 1990s. In 2016, Birdlife International classified the Sulu
Boobook as Vulnerable, citing its declining population, estimated at fewer than
1,000 individuals, and threats from deforestation, and other anthropogenic
disturbances. In 2019, the Department of Environment and Natural Resources
(DENR) Administrative Order No. 2019-09 also listed the species as Vulnerable,
highlighting the critical need for updated field observations.
This article reports
a new sighting of the Sulu Bobook at the Bolobok Rock Shelter, an unrecorded location for this
species situated along the coast overlooking the Sulu Sea in Barangay Lakit-Lakit, Bongao, Tawi-Tawi (Figure 1). An individual was observed at noon on
10 July 2023, perched quietly but alertly on the limestone ceiling at the
entrance of Bolobok Rock Shelter at an elevation of
13.41 m (Image 1).
The immediate
environment was characterized by a karstic limestone formation with an
irregular and rugged surface (Image 2). The texture of the rock behind the owl
was rough and pitted with erosion features, which are common in limestone that
has been subjected to dissolution by acidic rainwater over time. Vegetation
around the perch was sparse. The owl was perched on a bare, slender vine. The
surrounding rock served as a microhabitat that likely supported various forms
of wildlife, including this owl, which seemed well adapted to blend into the
grayish-brown palette of the rock face. The crevices and fissures in the rocks
could have provided shelter and nesting spots for the owl and other avian
species. The shaded location of the rock shelter, coupled with its humid and
quiet ambiance, are conditions that are often preferred by owls for roosting (Rebollo et al. 2023).
The owl exhibited a
sense of undisturbed tranquility in the presence of observers, providing an
opportunity to document and confirm its identification. It was confirmed as a
Sulu Boobook based on key morphological features: prominent uniformly barred on
crown and breast, distinctive mustard-yellow eyes, prominent white “X” markings
around the bill, and a noticeable white patch on its throat, which match the
characteristics of the species as described in Kennedy et al. (2000) and
Rasmussen et al. (2012).
Bolobok Rock Shelter,
located in Barangay Lakit-Lakit, Bongao,
Tawi-Tawi—the southernmost province of the Sulu
Archipelago—is an Important Cultural Property (National Museum Declaration No.
24-2016). It holds significant prehistoric artifacts, including polished shell
adzes from Tridacna gigas, showcasing early
tool-making (Faylona 2010; Bautista 2022; Muallil et al. 2024). Radiocarbon dating places these
artifacts between 6810–3190 BCE (8,760–5,140 years ago), making Bolobok one of the Philippines’ earliest known human
settlements.
On the other hand, Lakit-Lakit is a remote barangay in Bongao,
located along the Sibutu Passage in the northern part
of the municipality. It has a population of about 1,500 and a coastal length of
2.72 km. The majority of its residents rely on farming, making Lakit-Lakit a primary source of agricultural produce in Bongao, which is the capital and commercial center in the
province of Tawi-Tawi. Lakit-Lakit
was once densely forested but suffered severe deforestation due to extensive
logging and farming expansion, particularly in the 1990s (Sansawi
et al. 2020). The local residents identified the species as ‘lukluk’ in Tausug and ‘mongkok’
in Sinama. They reported hearing the calls of the
bird early in the evening and sometimes spotting the birds in trees near
residential areas.
The discovery of the
Sulu Boobook at Bolobok Rock Shelter not only
provides a new locality record for Lakit-Lakit but
also underscores the species’ adaptability to varied microhabitats, suggesting
that the Sulu Boobook may have a wider range than previously documented. A
single sighting of the species in a new locality does not necessarily confirm a
resident population, as its high mobility suggests it may be transient. To establish
a sustained population at Bolobok Rock Shelter,
multiple sightings over time, evidence of breeding pairs, or juveniles are
necessary (Pradel & Sanz-Aguilar 2012).
Nevertheless, this finding underlines the urgency for comprehensive field
surveys and conservation efforts to ensure the survival of this vulnerable owl.
Additionally, our research highlights the critical need to protect the Bolobok Rock Shelter, not only as a cornerstone of cultural
heritage but also as an essential habitat for this species.
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