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Drivers of bird diversity in an understudied African centre of endemism: The Angolan Central Escarpment Forest

  • AIMY CÁCERES (a1) (a2) (a3), MARTIM MELO (a2) (a3) (a4), JOS BARLOW (a5), RICARDO FAUSTINO DE LIMA (a6) (a7) and MICHAEL S. L. MILLS (a8) (a3)...


Natural habitats are being rapidly lost due to human activities. It is therefore vital to understand how these activities influence biodiversity so that suitable guidelines can be established for conservation. This is particularly important in understudied, high biodiversity, areas such as the Angolan Escarpment. Here we examine which habitat characteristics drive bird diversity and endemic species presence at Kumbira Forest, a key site in the Central Escarpment Forest. Bird diversity was sampled by 10 min bird point counts, whereas habitat characteristics were measured by a combination of ground-based vegetation surveys and remotely sensed data modelling of Landsat images. GLM, multi-model inference and model averaging were used to determine the most important variables driving species richness and the presence of endemics. The remote sensing variables performed poorly in predicting presence of Red-crested Turaco Tauraco erythrolophus and Gabela Bushshrike Laniarius amboimensis but they contributed significantly to explain species richness and Gabela Akalat Sheppardia gabela presence, both of which were associated with greater canopy cover. Liana density and elevation were also important explanatory variables in certain cases. Conservation actions at Kumbira should focus on increasing canopy cover and maintaining forest integrity (as measured by liana density), as these actions are likely to have the most positive outcomes for the avifauna.


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Anderson, D. R. and Burnham, K. P. (2002) Avoiding pitfalls when using information-theoretic methods. J. Wildl. Manage. 66: 912918.
Aplin, P. (2005) Remote sensing: ecology. Progr. Phys. Geogr. 29: 104113.
Baddeley, A., Turner, R., Moller, J. and Hazelton, M. (2005) Residual analysis for spatial point processes. J, Roy. Statist. Soc. Ser. B-Statist. Methodol. 67: 617651.
Barton, K. (2013) MuMin: Multi-model inference. R package. Vol. 1.9.13.
Bibby, C., Burgess, N., Hill, D. and Mustoe, S. (2000) Bird census techniques: London, UK: Academic Press.
BirdLife International. (2015a) Endemic Bird Area factsheet: Western Angola.
BirdLife International. (2015b) IUCN Red List for birds.
Bradshaw, C. J. A., Sodhi, N. S. and Brook, B. W. (2009) Tropical turmoil: a biodiversity tragedy in progress. Frontiers Ecol. Environ. 7: 7987.
Brooks, T. M., Mittermeier, R. A., Mittermeier, C. G., Rylands, A. B., Konstant, W. R., Flick, P., Pilgrim, J. D., Oldfield, S., Magin, G. and Hilton-Taylor, C. (2002) Habitat loss and extinction in the hostspots of biodiversity. Conserv. Biol. 16: 909923.
Buechley, E. R., Sekercioglu, Ç., Atickem, A., Gebremichael, G., Ndungu, J. K., Mahamued, B. A., Beyene, T., Mekonnen, T. and Lens, L. (2015) Importance of Ethiopian shade coffee farms for forest bird conservation. Biol. Conserv. 188: 5060.
Burnham, K. P. and Anderson, D. R. (2002) Model selection and multimodel inference: A practical information-theoretic approach, New York, USA: Springer-Verlag.
Burnham, K. P. and Anderson, D. R. (2004) Understanding AIC and BIC in model selection. Sociol. Meth. Res. 33: 261304.
Burnham, K. P., Anderson, D. R. and Huyvaert, K. (2011) AIC model selection and multimodel inference in behavioral ecology: some background, observations and comparisons. Behav. Ecol. Sociobiol. 63: 2335.
Cáceres, A., Melo, M., Barlow, J., Cardoso, P., Maiato, F. and Mills, M. (2015) Threatened birds of the Angolan Central Escarpment: distribution and response to habitat change at Kumbira Forest. Oryx 49: 727734.
Chave, J., Réjou-Mechain, M., Búrquez, A., Chidumayo, E., Colgan, M. S., Delitti, W. B. C., Duque, A., Eid, T., Fearnside, P. M., Goodman, R. C., Henry, M., Martinez-Yrizar, A., Mugasha, W. A., Muller-Landau, H., Mencuccini, M., Nelson, B. W., Ngomanda, A., Nogueira, E. M., Ortiz-Malavassi, E., Pélissier, R., Ploton, P., Ryan, C. M., Saldarriaga, J. G. and Vielledent, C. (2014) Improved allometric models to estimate aboveground biomass of tropical trees. Global Change Biol. 20: 31773190.
Chavez, P. S. (1996) Image-based atmospheric corrections revisited and improved. Photogrammetric Engineering and Remote Sensing 62: 10251036.
Chazdon, R. L., Peres, C. A., Dent, D., Sheil, D., Lugo, A. E., Lamd, D., Stork, N. E. and Miller, S. E. (2009) The potential for species conservation in tropical secondary forests. Conserv. Biol. 23: 14061417.
Cincotta, R., Wisnewski, J. and Engelman, R. (2000) Human population in the biodiversity hotspots. Nature 404: 990992.
Collar, N. J. and Stuart, S. N. (1988) Key forests for threatened birds in Africa: Cambridge, UK: International Council for Bird Preservation.
Dallimer, M. and King, T. (2007) Habitat preferences of the forest birds on the island of Príncipe, Gulf of Guinea. Afr. J. Ecol. 46: 258266.
Dallimer, M., King, T. and Atkinson, R. J. (2009) Pervasive threats within a protected area: conserving the endemic birds of São Tomé, West Africa. Anim. Conserv. 12: 209219.
Dallimer, M., Parnell, M., Bicknell, J. E. and Melo, M. (2012) The importance of novel and agricultural habitats for the avifauna of an oceanic island. J. Nat. Conserv. 20: 191199.
de Lima, R., Dallimer, M., Atkinson, P. W. and Barlow, J. (2013) Biodiversity and land-use change: understanding the complex responses of an endemic-rich bird assemblage. Divers. Distrib. 19: 411422.
Dean, W. R. J. (2001) Angola. Pp. 7191 in Fishpool, L. D. C. and Evans, M. I., eds. Important Birds Areas in Africa and associated islands: Priority sites for conservation. Newbury and Cambridge, UK: Pisces Publications and BirdLife International.
Gardner, T., Barlow, J., Chazdon, R., Ewers, R., Harvey, C., Peres, C. and Sodhi, N. (2009) Prospects for tropical forest biodiversity in a human-modified world. Ecol. Lett. 12: 561582.
Gardner, T., Barlow, J., Sodhi, N. and Peres, C. (2010) A multi-region assessment of tropical forest biodiversity in a human-modified world. Biol. Conserv. 143: 22932300.
Gibson, L., Ming Lee, T., Pin Koh, L., Brook, B. W., Gardner, T. A., Barlow, J., Peres, C. A., Bradshaw, C. J. A., Laurance, W. F., Lovejoy, T. E. and Sodhi, N. S. (2011) Primary forests are irreplaceable for sustaining tropical biodiversity. Nature 478: 378381.
Gove, A., Hylander, K., Nemomisa, S. and Shimelis, A. (2008) Ethiopian coffee cultivation—Implications for bird conservation and environmental certification. Conserv. Lett. 1: 208216.
Hall, B. P. (1960) The faunistic importance of the scarp in Angola. Ibis 102: 420442.
Hawkins, F. (1993) An integrated biodiversity conservation project under development: the ICBP Angola scarp project. Pp. 279284 in Wilson, R., ed. Proceedings of the 8th Pan-African Ornithological Congress. Tervuren, Belgium: Annales Musée Royal de l’Afrique Centrale (Zoologie).
Henry, M., Besnard, A., Asante, W. A., Eshun, J., Adu-Bredu, S., Valentini, R., Bernoux, M. and Saint-André, L. (2010) Wood density, phytomass variations withing and among trees, and allometric equations in a tropical rainforest of Africa. For. Ecol. Manage. 260: 13751388.
Huete, A., Didan, K., Miura, T., Rodriguez, E. P., Gao, X. and Ferreira, L. G. (2002) Overview of the radiometric and biophysical performance of the MODIS vegetation indices. Remote Sensing Environ. 83: 195213.
Huntley, B. J. (1974) Outlines of wildlife conservation in Angola. J. South Afr. Wildl. Manage. Assoc. 4: 157166.
Huntley, B. J. and Matos, E. M. (1994) Botanical diversity and its conservation in Angola. Strelitzia 1: 5374.
Hurvich, C. M. and Tsai, C.-L. (1989) Regression and time series model selection in small samples. Biometrika 79: 297307.
Jensen, J. R. (2005) Introductory digital image processing: A remote sensing perspective. Upper Saddle River, NJ: Prentice Hall.
Kerr, J. T. and Ostrovsky, M. (2003) From space to species: ecological applications for remote sensing. Trends Ecol. Evol. 18: 299305.
Kremen, C., Cameron, A., Moilanen, A., Phillips, S. J., Thomas, C. D., Beentje, H., Dransfield, J., Fisher, B. L., Glaw, F., Good, T. C., Harper, G. J., Hijmans, R. J., Lees, D. C., Louis, E., Nussbaum, R. A., Raxworthy, C. J., Razafimpahanana, A., Schatz, G. E., Vences, M., Vieites, D. R., Wright, P. C. and Zjhra, M. L. (2008) Aligning conservation priorities across taxa in Madagascar with high-resolution planning tools. Science 320: 222226.
Kühn, I. and Dormann, C. F. (2012) Less than eight ( and a half ) mis-conceptions of spatial analysis. J. Biogeogr. 39: 995998.
Legendre, P. and Legendre, L. (1998) Numerical ecology, Amsterdam, The Netherlands: Elsevier Scientific Publising Company.
Mammides, C., Schleuning, M., Bohning-Gaese, K., Schaab, G., Farwing, N., Kadis, C. and Coulson, T. (2015) The indirect effects of habitat disturbance on bird communities in a tropical African forest. Biodivers. Conserv. 24: 30833107.
Mills, M. (2010) Angola’s central scarp forests: patterns of bird diversity and conservation threats. Biodivers. Conserv. 19: 18831903.
Myers, N., Mittermeier, R. A., Mittermeier, C. G., da Fonseca, G. A. B. and Kent, J. (2000) Biodiversity hotspots for conservation priorities. Nature 403: 853858.
Nagendra, H. (2001) Using remote sensing to assess biodiversity. Internatn. J. Remote Sensing 22: 23772400.
Nagendra, H. and Rocchini, D. (2008) High resolution satellite imagery for tropical biodiversity studies: the devil is in the detail. Biodivers. Conserv. 17: 34313442.
Nelder, J. A. and Wedderburn, R. W. M. (1972) Generalized Linear Models. J. Roy. Statist. Soc. Ser. A (General) 135: 370384.
Norris, K., Asase, A., Collen, B., Gockowski, J., Mason, J., Phalan, B. and Wade, A. (2010) Biodiversity in a forest-agriculture mosaic - The changing face of West African rainforests. Biol. Conserv. 143: 23412350.
Oksanen, J., Blanchet, G. F., Kindt, R., Legendre, P., Minchin, P. R., O’Hara, R. B., Simpson, G. L., Solymos, P., Stevens, H. H. and Wagner, H. (2012) Vegan: Community Ecology Package. R package version 2.0-5.
Paustian, K., Ravindranath, N. H. and Van Amstel, A. (2006) Agriculture, forestry and other land use. Pp. 448 in Eggleston, H. S., Buendia, L., Miwa, K., Ngara, T. and Tanabe, K., eds. 2006 IPCC guidelines for national greenhouse gas inventories. Tokyo, Japan: National Greenhouse Gas Inventories Programme.
Pettorelli, N., Olav Vik, J., Mysterud, A., Gaillard, J.-M., Tucker, C. J. and Stenseth, N. C. (2005) Using the satellite-derived NDVI to assess ecological responses to environmental change. Trends Ecol. Evol. 20: 503510.
R Core Team. (2015) R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing.
Ryan, P. G., Sinclair, I., Cohen, C., Mills, M., Spottiswoode, C. and Cassidy, R. (2004) The conservation status and vocalizations of threatened birds from the scarp forest of the Western Angola Endemic Area. Bird Conserv. Internatn. 14: 247260.
Schnitzer, S. A. and Bongers, F. (2002) The ecology of lianas and their role in forests. Trends Ecol. Evol. 17: 223230.
Schulze, C. H., Waltert, M., Kessler, P. J. A., Pitopang, R., Shahabuddin Dorthe, V., Mühlenberg, M., Gradstein, S. R., Leuschner, C., Steffan-Dewenter, I. and Tscharntke, T. (2004) Biodiversity indicator groups of Tropical land-use systems: comparing plants, birds, and insects. Ecol. Applic. 14: 13211333.
Sekercioglu, Ç. and Riley, A. (2005) A brief survey of the birds in Kumbira Forest, Gabela, Angola. Ostrich 76: 111117.
Stattersfield, A. and Capper, D. (2000) Threatened birds of the world. Barcelona: Lynx Edicions.
USAID (2008) Biodiversity and tropical forest asssessment for Angola. Available at:
Wang, K., Franklin, S. E., Guo, X. and Cattet, M. (2010) Remote sensing of ecology, biodiversity and conservation: a review from the perspective of remote sensing specialists. Sensors 10: 96479667.
Xiao, X., Boles, S., Frolking, S., Salas, W., Moore, B. III, Li, C., He, L. and Zhao, R. (2002) Observation of flooding and rica transplatting of paddy rice fields at the site to landscape scales in China using vegetation sensor data. Internatn. J. Remote Sensing 23: 30093022.
Zuur, A. F., Ieno, E. N. and Smith, G. M. (2007) Analysing ecological data, New York, USA: Springer-Verlag.
Zuur, A. F., Ieno, E. N., Walker, N. J., Saveliev, A. A. and Smith, G. M. (2009) Mixed effects models and extensions in ecology with R. New York, USA: Springer-Verlag.
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