Skip to main content
×
Home
    • Aa
    • Aa

Habitat selection and conservation status of the endemic Ninox hawk-owl on Cebu, Philippines

  • P. GODFREY C. JAKOSALEM (a1), NIGEL J. COLLAR (a2) and JENNIFER A. GILL (a3)
Summary
Summary

The largely deforested island of Cebu, Philippines, hosts a forest-dwelling hawk-owl identified in the literature as Ninox philippensis spilonota but which is in fact a Cebu island endemic species, soon to be named. To determine the current distribution and habitat requirements of this hawk-owl, the five largest of 11 remaining forest patches on Cebu were surveyed between March and June 2011, involving 64 post-sunset 500-m walked transects with playback and habitat assessments. Radio-telemetry studies were also conducted on 10 owls but only for 3–5 days per owl as they removed the transmitters. A total of 52 owls were located across all five forests (at 16 sites two owls responded together to playback) but only the largest forest, Alcoy, contained enough transects for analyses of habitat in relation to owl distribution. Alcoy stands on steep-sided hills and some planting of exotic species occurs within it. Owls were detected in forest interior, forest edge and forest-plantation mix in Alcoy, and on ridges and in gullies despite lower tree densities and greater proximity to clearings in the gullies. However, parts of Alcoy experience strong winds, and owl occupancy decreased significantly with increasing wind speed. Home ranges for the 10 radio-tagged owls were estimated to cover ∼10 ha, although given the short tracking periods this may be an underestimate. Suitable forest studied covers roughly 1,670 ha, with six unstudied forests totalling 250 ha, so assuming a pair every 10 ha would give a tentative global population estimate of ∼ 200 pairs of Cebu Hawk-owls, and even fewer if home ranges are larger than estimated. This, coupled with continuing habitat degradation, triggers the IUCN Red List category ‘Endangered’. Tree cavities suitable for nests may be limiting, and nest-box provision could be explored, provided this does not increase predator pressure on other rare species.

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Habitat selection and conservation status of the endemic Ninox hawk-owl on Cebu, Philippines
      Available formats
      ×
      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about sending content to Dropbox.

      Habitat selection and conservation status of the endemic Ninox hawk-owl on Cebu, Philippines
      Available formats
      ×
      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about sending content to Google Drive.

      Habitat selection and conservation status of the endemic Ninox hawk-owl on Cebu, Philippines
      Available formats
      ×
Copyright
Corresponding author
*Author for correspondence; email: j.gill@uea.ac.uk
References
Hide All
Bell P. J. and Mooney N. (2002) Distribution, habitat and abundance of Masked Owls (Tyto novaehollandiae) in Tasmania. Pp.120132 in Newton I., Kavanagh R., Olsen J. and Taylor I., eds. Ecology and conservation of owls. Victoria, Australia: CSIRO Publishing.
Bensel T. (2008) Fuelwood, deforestation, and land degradation: 10 years of evidence from Cebu Province, the Philippines. Land Degradation & Development 19: 587605.
BirdLife International (2011) www.birdlife.org/datazone/species. Accessed August 2011.
Brooks T. M., Magsalay P., Dutson G. and Allen R. (1995) Forest loss, extinctions and last hope for birds on Cebu. Oriental Bird Club Bull. 21: 2427.
Cockle K. L, Martin K. and Drever M. C. (2010) Supply of tree-holes limits nest density of cavity-nesting birds in primary and logged subtropical Atlantic forest. Biol. Conserv. 143: 28512857.
Collar N. J. (1998) Extinction by assumption; or, the Romeo Error on Cebu. Oryx 32: 239243.
Collar N. J. and Rasmussen P. C. (1998) Species limits in the Ninox philippensis complex. Ostrich 69: 398 (Proc. 22 Internatn. Orn. Congr.).
Dickinson E. C., ed. (2003) The Howard & Moore complete checklist of the birds of the world. Third edition. London: Christopher Helm.
Dickinson E. C., Kennedy R. S. and Parkes K. C. (1991) The birds of the Philippines: an annotated check-list. Tring: British Ornithologists’ Union (Check-list no. 12).
Forsman E. D., Kaminske T. J., Lewis J. C., Maurice K. J. and Sovern S. G. (2005) Home range and habitat use of northern spotted owls on the Olympic Peninsula, Washington. J. Raptor Res. 39: 365377.
Gonzalez J. C., Dans A. T. L., Pedregosa M. G., Chiu C. and Villahermosa R. (1999) Island-wide survey of forest and fauna and flora inventory of selected sites for priority conservation on Cebu. Manila: Fauna & Flora International (unpublished).
Hooge P. N. and Eichenlaub B. (2000) Animal movement extension to ArcView. ver. 2.0. Anchorage: Alaska Science Center Biological Science Office, U.S. Geological Survey.
Kenward R. E. (2004) Radio tagging. Pp.141156 in Sutherland W. J., Newton I. and Green R. E., eds. Bird ecology and conservation: a handbook of techniques. Oxford: Oxford University Press.
Magsalay P., Brooks T., Dutson G. and Timmins R. (1995) Extinction and conservation on Cebu. Nature 373: 294.
Mazur K. M., Frith S. D. and James P. C. (1998) Barred owl home range and habitat selection in the boreal forest of central Saskatchewan. Auk 115: 746754.
McGregor R. C. (1909–1910) A manual of Philippine birds. Manila: Bureau of Printing.
Newton I. (1994) The role of nest sites in limiting the numbers of hole-nesting birds: a review. Biol. Conserv. 70: 265276.
Oldfield S., Lusty C. and MacKinven A. (1998) The world list of threatened trees. Cambridge, UK: World Conservation Press.
Olsen P. D. (1999) Genus Ninox species accounts. Pp. 231237 in del Hoyo J., Elliott A. D. and Sargatal J., eds. The Handbook of birds of the world, 5. Barcelona: Lynx Edicions.
Paguntalan L. M. J. (2009) Cebu local forest conservation areas: assessment and action plan. Cebu, Philippines: Cebu Biodiversity Conservation Foundation, Inc. and Department and Environment and Natural Resources-VII.
Paguntalan L. M. J. and Jakosalem P. G. C. (2008) Significant records of birds in forests on Cebu island, central Philippines. Forktail 24: 4856.
Rabor D. S. (1959) The impact of deforestation on birds of Cebu, with new records for that island. Auk 76: 3743.
Rasmussen P. C., Allen D. N. S., Collar N. J., Demeulemeester B., Hutchinson R. O., Jakosalem P. G. C., Kennedy R. S., Lambert F. R., & Paguntalan L. M. (in press) Vocal divergence and new species in the Philippine Hawk Owl Ninox philippensis complex. Forktail 28.
Taylor I. R., Kirsten I. and Peake P. (2002) Habitat, breeding and conservation of the Barking Owl Ninox connivens in northeastern Victoria, Australia. Pp.116124 in Newton I., Kavanagh R., Olsen J. and Taylor I., eds. Ecology and conservation of owls. Victoria, Australia: CSIRO Publishing.
Virani M. (2010) Home range and movement patterns of Sokoke Scops Owl Otus ireneae. Ostrich 71: 139142.
White G. C. and Garrott R. A. (1990) Analysis of wildlife radio-tracking data. San Diego, CA: Academic Press,
Worton B. J. (1989) Kernel methods for estimating the utilization distribution in home range studies. Ecology 70: 164168.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Bird Conservation International
  • ISSN: 0959-2709
  • EISSN: 1474-0001
  • URL: /core/journals/bird-conservation-international
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 4
Total number of PDF views: 14 *
Loading metrics...

Abstract views

Total abstract views: 138 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 21st October 2017. This data will be updated every 24 hours.