Conservation ecology of birds in Mt. Hilong-hilong, a Key Biodiversity Area on Mindanao Island, the Philippines

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Arturo G. Gracia Jr.
Alma B. Mohagan
Janezel C. Burlat
Welfredo L. Yu Jr.
Janine Mondalo
Florfe M. Acma
Hannah P. Lumista
Riah Calising
Krizler Cejuela Tanalgo


The identification of key areas for conservation and protection according to science-based evidence is an important component to circumvent the negative impacts of environmental changes within geopolitical territories and across the globe.  Priority areas for biodiversity played an important role to ensure the protection of many species particularly those that are unique and threatened.  There are more than 200 Key Biodiversity Areas (KBAs) in the Philippines, yet many important research and biodiversity data are either unpublished or unconsolidated.  Birds are commonly studied indicators for KBA identification due to their high species richness, diversity, and sensitivity to forest ecosystems.  By combining data from past and present surveys, we accounted for a total of 148 bird species of 51 families, with 20 new records from recent field surveys.  Our analysis showed a high level of endemism within Mt. Hilong-hilong with 36% Philippine endemic, 14% restricted to Mindanao faunal region and 11% migrant. In terms of conservation, 8% of the species were considered in threatened categories.  The species richness and endemism were higher in lowland to mid-elevation areas compared to higher elevation areas of the KBA.  Endemism (i.e., Mindanao endemic) and increasing body mass were important determinants of binary extinction risk for bird species in Mt. Hilong-hilong.  The high biodiversity in Mt. Hilong-hilong indicates an example of the vital role of KBAs in preserving nationally and globally important bird species.  Lastly, we emphasise the importance of collaboration and integrating past and present information to synthesise relevant information to complement ongoing conservation efforts in Mt. Hilong-hilong and other key habitats in the Philippines.

Article Details

Author Biography

Krizler Cejuela Tanalgo, Department of Biological Sciences, College of Arts and Sciences, University of Southern Mindanao

Instructor of Biology, Department of Biological Sciences, University of Southern Mindanao


Acharya, B.K., N.J. Sanders, L. Vijayan & B. Chettri (2011). Elevational Gradients in Bird Diversity in the Eastern Himalaya: An Evaluation of Distribution Patterns and Their Underlying Mechanisms. PLOS ONE 6(12): e29097. DOI:

Ambal, R.G.R., M.V. Duya, M.A. Cruz, O.G. Coroza, S.G. Vergara, N. de Silva, N. Monliyaw & B. Tabaranza (2012). Key Biodiversity Areas in the Philippines: Priorities for Conservation. Journal of Threatened Taxa 2788–2796. DOI:

Amoroso, V.B., A.B Mohagan, F.P Coritico, S.H Laraga, N. Lagunday, K.L. Domingo, R.D. Colong & R.G. Ponce (2019). Status of Mammals in the Expansion Sites of the Mt. Hamiguitan Range Wildlife Sanctuary, Mindanao, Philippines. Journal of Environmental Science and Management 22(2): 6–12.

Amoroso, V.B., A.B. Mohagan, F.P. Coritico, N.E. Lagunday, A.P. Yorong, R.D. Colong & R.G. Ponce (2018). Avifaunal assemblage in the expansion sites of the Mt. Hamiguitan Range Wildlife Sanctuary, Mindanao, Philippines. Nature Conservation Research 3: 103–109. DOI:

Beresford, A.E., P.F., Donald & G.M. Buchanan (2020). Repeatable and standardised monitoring of threats to Key Biodiversity Areas in Africa using Google Earth Engine. Ecological Indicators 109: 105763. DOI:

Bohada‐Murillo, M., G.J. Castaño‐Villa & F.E. Fontúrbel (2020). The effects of forestry and agroforestry plantations on bird diversity: A global synthesis. Land Degradation & Development 31(5): 646–654. DOI:

Brooks, T.M., R.A. Mittermeier, C.G. Mittermeier, G.A.B.D. Fonseca, A.B. Rylands, W.R. Konstant, P. Flick, J. Pilgrom, S. Oldfield, G. Magin & C. Hilton‐Taylor (2002). Habitat Loss and Extinction in the Hotspots of Biodiversity. Conservation Biology 16(4): 909–923. DOI:

Brooks, T.M., S.L. Pimm, V. Kapos & C. Ravilious (1999). Threat from deforestation to montane and lowland birds and mammals in insular South-east Asia. Journal of Animal Ecology 68(6): 1061–1078. DOI:

Bujoczek, M., J. Rybicka & L. Bujoczek (2020). Effects of disturbances in a subalpine forest on its structural indicators and bird diversity. Ecological Indicators 112: 106126. DOI:

Butchart, S.H.M., M. Clarke, R.J. Smith, R.E. Sykes, J.P.W. Scharlemann, M. Harfoot, G.M.Buchanan, A. Angulo, A., Balmford, B. Bertzky, T.M. Brooks, K.E. Carpenter, M.T. Comeros-Raynal, J. Cornell, G.G. Ficetola, L.D.C. Fishpool, R.A. Fuller, J. Geldman, H. Harwell, C. Hilton-Taylor, M. Hoffman, A. Joolia, L. Joppa, N.Kingston,I. May, A. Milam, B. Polidoro, G. Talph, N. Richman. C. Rondinimi, D. Segan, B. Skolnik, M. Spalding, S.N. Stuart, A. Symes, J. Taylor, P. Visconti, J. Watson, L. Wood & N.D. Burges (2015). Shortfalls and Solutions for Meeting National and Global Conservation Area Targets. Conservation Letters 8(5): 329–337. DOI:

Cai, M. & D. Pettenella (2013). Protecting biodiversity outside protected areas: can agricultural landscapes contribute to bird conservation on Natura 2000 in Italy? Journal of Environmental Engineering and Landscape Management 21(1): 1–11. DOI:

Canterbury, G.E., T.E. Martin, D.R. Petit, L.J. Petit & D.F. Bradfor (2000). Bird Communities and Habitat as Ecological Indicators of Forest Condition in Regional Monitoring. Conservation Biology 14(2): 544–558. DOI:

Daniels, R.J., N.V. Joshi & M. Gadgil (1992). On the relationship between bird and woody plant species diversity in the Uttara Kannada district of south India. Proceedings of the National Academy of Sciences 89(12): 5311–5315. DOI:

Davidar, P., J.P. Puyravaud & E.G. Leigh (2005). Changes in rain forest tree diversity, dominance and rarity across a seasonality gradient in the Western Ghats, India. Journal of Biogeography 32(3): 493–501. DOI:

Derhé, M.A., D. Tuyisingize, W. Eckardt, F. Emmanuel & T. Stoinski (2020). Status, diversity and trends of the bird communities in Volcanoes National Park and surrounds, Rwanda. Bird Conservation International 30(1): 1–20. DOI:

Donázar, J.A., A. Cortés-Avizanda, J.A. Fargallo, A. Margalida, M. Moleón, Z. Morales-Reyes, R. Moreno-Opo, J.M. Perez-Garcia, J.A. Sanchez-Zapata, I. Zuberogoitia & D. Serrano (2016). Roles of Raptors in a Changing World: From Flagships to Providers of Key Ecosystem Services. Ardeola 63(1): 181–234. DOI:

Dutson, G.C.L., P.M. Magsalay & R.J. Timmins (1993). The rediscovery of the Cebu Flowerpecker Dicaeum Quadricolor, with notes on other forest birds on Cebu, Philippines. Bird Conservation International 3(3): 235–243. DOI:

Eken, G., L. Bennun, T.M. Brooks, W. Darwall, L.D.C. Fishpool, M. Foster, D. Knox, P. Langhammer, P. Matiku, E. Radford, P. Salaman, W. Sechrest, M.L. Smith, S. Spector & A. Tordoff (2004). Key Biodiversity Areas as Site Conservation Targets. BioScience 54(12): 1110–1118.[1110:KBAASC]2.0.CO2

Fried, G., S. Cordeau, A. Metay & E. Kazakou(2019). Relative importance of environmental factors and farming practices in shaping weed communities structure and composition in French vineyards. Agriculture, Ecosystems & Environment 275: 1–13. DOI:

García, D. & D. Martínez (2012). Species richness matters for the quality of ecosystem services: a test using seed dispersal by frugivorous birds. Proceedings of the Royal Society B: Biological Sciences 279(1740): 3106–3113. DOI:

Global Forest Watch (2020). Forest Monitoring, Land Use & Deforestation Trends | Global Forest Watch accessed 18 March 2021.

Gonzales, R.S., N.R. Ingle, D.A. Lagunzad & T. Nakashizuka (2009). Seed Dispersal by Birds and Bats in Lowland Philippine Forest Successional Area. Biotropica 41(4): 452–458. DOI:

Gonzalez, J.C.T., B.C. Sheldon, N.J. Collar & J.A. Tobias (2013). A comprehensive molecular phylogeny for the hornbills (Aves: Bucerotidae). Molecular Phylogenetics and Evolution 67(2): 468–483. DOI:

Hatfield, J.H., J. Barlow, C.A. Joly, A.C. Lees, C.H.D.F Parruco, J.A. Tobias, C.D. Orme & C. Banks‐Leite (2020). Mediation of area and edge effects in forest fragments by adjacent land use. Conservation Biology 34(2): 395–404. DOI:

Heaney, L.R. & J.C. Regalado (1998). Vanishing treasures of the Philippine rain forest. Vanishing Treasures of the Philippine Rain Forest.

Ingle, N.R. (2003). Seed dispersal by wind, birds, and bats between Philippine montane rainforest and successional vegetation. Oecologia 134(2): 251–261. DOI:

IUCN (2020). The IUCN Red List of Threatened Species. Version 2020-2 accessed 27 October 2020.

Jankowski, J.E., C.L. Merkord, W.F. Rios, K.G. Cabrera, N.S. Revilla & M.R. Silman (2013). The relationship of tropical bird communities to tree species composition and vegetation structure along an Andean elevational gradient. Journal of Biogeography 40(5): 950–962. DOI:

Kattan, G.H. & P. Franco (2004). Bird diversity along elevational gradients in the Andes of Colombia: area and mass effects. Global Ecology and Biogeography 13(5): 451–458. DOI:

Kennedy, R., P.C. Gonzales, E. Dickinson, H.C. Jr. Miranda & T.H. Fisher (2000). A guide to the birds of the Philippines. Oxford University Press, 540+72 color plates.

Knight, A.T., R.J. Smith, R.M. Cowling, P.G. Desmet, D.P. Faith, S. Ferrier, C.M. Gelderblom, H. Grantham, A.T. Lombard, K. Maze, J.L. Nel, J.D. Parrish, G.Q.K. Pence, H.P. Possingham, B. Reyers, M. Rouget, D. Roux & K.A. Wilson (2007). Improving the Key Biodiversity Areas Approach for Effective Conservation Planning. BioScience 57(3): 256–261. DOI:

Koh, L.P. (2008). Birds Defend Oil Palms from Herbivorous Insects. Ecological Applications 18(4): 821–825. DOI:

Lelli, C., H.H. Bruun, A. Chiarucci, D. Donati, F. Frascaroli, Ö. Fritz, I. Goldberg, J. Nascimbene, A.P. Tottrup, C. Rahbek & J. Heilmann-Clausen (2019). Biodiversity response to forest structure and management: Comparing species richness, conservation relevant species and functional diversity as metrics in forest conservation. Forest Ecology and Management 423: 707–717. DOI:

Manu, S. & W.R. Cresswell (2007). Addressing sampling bias in counting forest birds: a West African case study. Ostrich 78(2): 281–286. DOI:

Margules, C.R. & R.L. Pressey (2000). Systematic conservation planning. Nature 405(6783): 243–253. DOI:

McCain, C.M. (2009). Global analysis of bird elevational diversity. Global Ecology and Biogeography 18(3): 346–360. DOI:

Mejías, M.A. & E. Nol (2020). Woodland size and vegetation effects on resident and non-resident woodland birds in Bermuda. Journal of Caribbean Ornithology 33: 22–32.

Mills, G.S., J.B. Dunning & J.M. Bates (1991). The Relationship between Breeding Bird Density and Vegetation Volume. The Wilson Bulletin 103(3): 468–479.

Mohagan, A.B., O.M. Nuñeza, A.G. Jr. Gracia, E.C.T. Selpa, J.A. Jr. Escarlos Jr, J.A., Baguhin, L.J.B., F.P. Coritico & V. Amoroso (2015). Species richness of avifauna in four Long-Term Ecological Research sites in Mindanao, Philippines. Journal of Applied Environmental and Biological Sciences 5(11): 88–89.

Mueller, T., J. Lenz, T. Caprano, W. Fiedler & K. Böhning‐Gaese (2014). Large frugivorous birds facilitate functional connectivity of fragmented landscapes. Journal of Applied Ecology 51(3): 684–692. DOI:

Nori, J., R. Loyola, & F. Villalobos (2020). Priority areas for conservation of and research focused on terrestrial vertebrates. Conservation Biology n/a(n/a). DOI:

O’Connell, T.J., L.E. Jackson & R.P. Brooks (2000). Bird Guilds as Indicators of Ecological Condition in the Central Appalachians. Ecological Applications 10(6): 1706–1721.[1706:BGAIOE]2.0.CO 2

Paz, S., O. Nuneza, D. Ngoprasert, N.A. Mallari & G. Gale (2013). Philippine-endemic and Mindanao-endemic Bird Communities on Canticol and Mt. Hilong-hilong, Philippines. Asian Journal of Biodiversity 4(1): 135–168. 10.7828/ajob.v4i1.301 DOI:

Peterson, A.T., L.G. Ball & K.W. Brady (2000). Distribution of the birds of the Philippines: biogeography and conservation priorities. Bird Conservation International 10(2): 149–167. DOI:

Plumptre, A.J., S. Ayebare, M. Behangana, T.G. Forrest, P. Hatanga, C. Kabuye, B. Kirunda, R. Kityo, H. Mugabe, M. Namaganda, S. Nampindo, G. Nangendo, D.N., Nkuuru, D. Pomeroy, H. Tushab & S. Prinsloo (2019). Conservation of vertebrates and plants in Uganda: Identifying Key Biodiversity Areas and other sites of national importance. Conservation Science and Practice 1(2): e7. DOI:

Posa, M.R.C., A.C. Diesmos, N.S. Sodhi & T.M. Brooks (2008). Hope for Threatened Tropical Biodiversity: Lessons from the Philippines. BioScience 58(3): 231–240. DOI:

Posa, M.R.C. & N.S. Sodhi (2006). Effects of anthropogenic land use on forest birds and butterflies in Subic Bay, Philippines. Biological Conservation 129(2): 256–270. DOI:

Rayner, L., D.B. Lindenmayer, J.T. Wood, P. Gibbons & A.D. Manning (2014). Are protected areas maintaining bird diversity? Ecography 37(1): 43–53. DOI:

Renjifo, L.M. (2001). Effect of Natural and Anthropogenic Landscape Matrices on the Abundance of Subandean Bird Species. Ecological Applications 11(1): 14–31.[0014:EONAAL]2.0.CO 2

Runge, C.A., J.E.M. Watson, S.H.M. Butchart, J.O. Hanson, H.P. Possingham & R.A. Fuller. (2015). Protected areas and global conservation of migratory birds. Science 350(6265): 1255–1258. DOI:

Sánchez-González, L.A. & R.G. Moyle (2011). Molecular systematics and species limits in the Philippine fantails (Aves: Rhipidura). Molecular Phylogenetics and Evolution 61(2): 290–299. DOI:

Sanguila, M.B., K.A. Cobb, C.D. Siler, A.C. Diesmos, A.C. Alcala & R.M. Brown (2016). The amphibians and reptiles of Mindanao Island, southern Philippines, II: the herpetofauna of northeast Mindanao and adjacent islands. ZooKeys (624): 1–132. DOI:

Santillán, V., M. Quitián, B.A. Tinoco, E. Zárate, M. Schleuning, K. Böhning-Gaese & E.L. Neuschulz (2020). Direct and indirect effects of elevation, climate and vegetation structure on bird communities on a tropical mountain. Acta Oecologica 102: 103500. DOI:

Segan, D.B., K.A. Murray & J.E.M. Watson (2016). A global assessment of current and future biodiversity vulnerability to habitat loss–climate change interactions. Global Ecology and Conservation 5: 12–21. DOI:

Sekercioglu, C.H. (2012). Bird functional diversity and ecosystem services in tropical forests, agroforests and agricultural areas. Journal of Ornithology 153(Suppl. 1): 153–161.

Sekercioglu, Ç.H., D.G. Wenny & C.J. Whelan (2016). Why Birds Matter: Avian Ecological Function and Ecosystem Services. University of Chicago Press, 398pp. DOI:

Sinclair, A.R.E., S.A.R. Mduma & P. Arcese (2002). Protected Areas as Biodiversity Benchmarks for Human Impact: Agriculture and the Serengeti Avifauna. Proceedings: Biological Sciences 269(1508): 2401–2405.

Tanalgo, K.C. (2017). Wildlife hunting by indigenous people in a Philippine protected area: a perspective from Mt. Apo National Park, Mindanao Island. Journal of Threatened Taxa 9(6): 10307–10313. DOI:

Tanalgo, K.C., M.J.M.M. Achondo & A.C. Hughes (2019). Small Things Matter: The Value of Rapid Biodiversity Surveys to Understanding Local Bird Diversity Patterns in Southcentral Mindanao, Philippines. Tropical Conservation Science 12: 1940082919869482. DOI:

Tanalgo, K.C. & A.C. Hughes (2019). Priority-setting for Philippine bats using practical approach to guide effective species conservation and policy-making in the Anthropocene. Hystrix, the Italian Journal of Mammalogy 30(1): 74–83.

Tanalgo, K.C., J.A.F. Pineda, M.E. Agravante & Z.M. Amerol (2015). Bird Diversity and Structure in Different Land-use Types in Lowland South-Central Mindanao, Philippines. Tropical Life Sciences Research 26(2): 85–103.

Tchoumbou, M.A., E.F.N. Malange, C.T. Tiku, B. Tibab, J. Fru-Cho, T. Tchuinkam, J. Awah-Ndukum, D.A. Nota & R.N.M. Sehgal (2020). Response of Understory Bird Feeding Groups to Deforestation Gradient in a Tropical Rainforest of Cameroon. Tropical Conservation Science 13: 1940082920906970. DOI:

The Jamovi Project (2020). Jamovi (Version 1.2) (Version 1.2)

The Philippine Eagle Foundation (2007). Eastern Mindanao Corridor Biodiversity Archiving and Assessment Project Report. A technical report.

Trindade-Filho, J., F.L. Sobral, M.V. Cianciaruso & R.D. Loyola (2012). Using indicator groups to represent bird phylogenetic and functional diversity. Biological Conservation 146(1): 155–162. DOI: