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The importance of protected and unprotected areas for colony occupancy and colony size in White-necked Picathartes Picathartes gymnocephalus in and around Gola Rainforest National Park, Sierra Leone



Most attention on tropical biodiversity conservation has focussed on protected areas. Recognising and enhancing the value of biodiversity outside, as well as inside, protected areas is increasingly important given recognition that biodiversity targets will not be met through protected areas alone. We investigated the extent to which protection influences colony occupancy and colony size of a species of conservation concern, the rock-nesting White-necked Picathartes Picathartes gymnocephalus. We used mixed models to compare long term trends at 42 colonies located both inside and outside a protected area of forest, Gola Rainforest National Park, and considered colonies further inside the boundary as being better protected. Colony occupation was primarily predicted by the level of protection, with occupation highest within protected areas, but was not different between colonies situated close to or far from the boundary. Mean colony occupation was consistently high in protected areas, and lower in unprotected areas. The surface area of colony rocks was also an important predictor with larger rock faces having a higher probability of occupancy. Our best models also included distance to forested habitat, presence of cleared forest and evidence of hunting as less important predictors. Over the eight-year study, after controlling for rock surface area, active colony size declined significantly. However, declines were only significant in colonies in unprotected forest, whilst colonies located within protected areas were buffered from significant decline. Together this suggests colony occupancy and the number of active nests are influenced by protection and human disturbance. Although a lack of demographic and population dynamic work on picathartes prevents identifying mechanisms, we show that despite unprotected colonies having lower occupancy and fewer active nests they can persist in human altered and disturbed areas, partly because larger traditionally used rocks remain important nesting sites.


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Allport, G., Ausden, M., Hayman, P., Robertson, P. and Wood, P. (1989) The conservation of the birds in Gola Forest, Sierra Leone. In ICBP Study Report. Cambridge, UK: BirdLife International.
Andam, K. S., Ferraro, P. J., Pfaff, A., Sanchez-Azofeifa, G. A. and Robalino, J. A. (2008) Measuring the effectiveness of protected area networks in reducing deforestation. Proc. Nat. Acad. Sci. 105: 1608916094.
Asamoah, A. (2011) The ecology, distribution and conservation of White-necked picathartes, Picathartes gymnocephalus in Ghana. PhD thesis. University of Ghana.
Atuo, F. A., Ivande, S. T., Wala, Z. and O’Connell, T. J. (2014) Effects of hunting camps on breeding grey-necked picathartes Picathartes oreas in south-east Nigeria. Oryx 48: 460464.
Awa, T II. (2008) The bio-ecology of grey-necked picathartes, Picathartes oreas: implications for conservation management. PhD thesis. University of Reading.
Awa, T. II, Burgess, M. D. and Norris, K. (2009a) Investigating the practicality of using radio tracking to determine home range and movements of Picathartidae. Ostrich 80: 145151.
Awa, T. II, Dzikouk, G. and Norris, K. (2009b) Breeding distribution and population decline of globally threatened Grey-necked Picathartes Picathartes oreas in Mbam Minkom Mountain Forest, southern Cameroon. Bird Conserv. Internatn. 19: 254264.
Barton, K. (2011) MuMIn: Multi-model inference. R package version 1.0.0. Available at: [Accessed 05 March 2015]
Beale, C. M. and Monaghan, P. (2004) Human disturbance: people as predation-free predators? J. Appl. Ecol. 41: 335343.
BirdLife International (2012) Picathartes gymnocephalus. The IUCN Red List of Threatened Species. Version 2015.4. [Accessed 16 March 2016].
Burnham, K. and Anderson, D. (2002) Model selection and multimodel inference. A practical information-theoretic approach. New York, USA: Springer.
Butchart, S. H. M., Clarke, M., Smith, R. J., Sykes, R. E., Scharlemann, J. P. W., Harfoot, M., Buchanan, G. M., Angulo, A., Balmford, A., Bertzky, B., Brooks, T. M., Carpenter, K. E., Comeros-Raynal, M. T., Cornell, J., Ficetola, G. F., Fishpool, L. D. C., Fuller, R. A., Geldmann, J., Harwell, H., Hilton-Taylor, C., Hoffmann, M., Joolia, A., Joppa, L., Kingston, N., May, I., Milam, A., Polidoro, B., Ralph, G., Richman, N., Rondinini, C., Segan, D. B., Skolnik, B., Spalding, M. D., Stuart, S. N., Symes, A., Taylor, J., Visconti, P., Watson, J. E. M., Wood, L. and Burgess, N. D. (2015) Shortfalls and solutions for meeting national and global conservation area targets. Conserv. Lett. 8: 329–327.
Carney, K. M. and Sydeman, W. J. (1999) A review of human disturbance effects on nesting colonial waterbirds. Waterbirds 22: 6879.
Christy, P. and Maisels, F. (2007) Grey-necked Picathartes Picathartes oreas use man-made structures to breed. Malimbus 29: 126128.
Crawley, M. J. (2007) The R book. Chichester, UK: John Wiley & Sons.
De Klerk, H., Fjeldså, J., Blyth, S. and Burgess, N. (2004) Gaps in the protected area network for threatened Afrotropical birds. Biol. Conserv. 117: 529537.
Finch, T., Pearce-Higgins, J., Leech, D. I. and Evans, K. (2014) Carry-over effects from passage regions are more important than breeding climate in determining the breeding phenology and performance of three avian migrants of conservation concern. Biodiv. Conserv. 23: 24272444.
Fry, C., Keith, S. and Urban, E. (2000) The Birds of Africa Volume 6. London, UK: Academic Press.
Harrison, R. D. (2011) Emptying the forest: Hunting and the extirpation of wildlife from tropical nature reserves. BioScience 61: 919924.
Jenkins, C. N. and Joppa, L. (2009) Expansion of the global terrestrial protected area system. Biol. Conserv. 142: 21662174.
Laurance, W. F., Useche, D. C., Rendeiro, J., Kalka, M., Bradshaw, C. J., Sloan, S. P., Laurance, S. G., Campbell, M., Abernethy, K. and Alvarez, P. (2012) Averting biodiversity collapse in tropical forest protected areas. Nature 489: 290294.
Lindsell, J. A., Klop, E. and Siaka, A. M. (2011) The impact of civil war on forest wildlife in West Africa: mammals in Gola Forest, Sierra Leone. Oryx 45: 6977.
Monticelli, D., Siaka, A., Buchanan, G. M., Wotton, S., Morris, T., Wardill, J. C. and Lindsell, J. A. (2011) Long term stability of White-necked Picathartes population in south-east Sierra Leone. Bird Conserv. Internatn. 22: 170183.
R Development Core Team. (2014) R: A Language and Environment for Statistical Computing. Vienna, Austria: R Foundation for Statistical Computing,
Rodrigues, A. S., Andelman, S. J., Bakarr, M. I., Boitani, L., Brooks, T. M., Cowling, R. M., Fishpool, L. D., da Fonseca, G. A., Gaston, K. J. and Hoffmann, M. (2004) Effectiveness of the global protected area network in representing species diversity. Nature 428: 640643.
Salewski, V., Göken, F., Korb, J. and Schmidt, S. (2000) Has the White-necked Picathartes Picathartes gymnocephala still a chance in Lamto, Ivory Coast? Bird Conserv. Internatn. 10: 4146.
Senapathi, D., Underwood, F., Black, E., Nicoll, M. A. C. and Norris, K. (2010) Evidence for long-term regional changes in precipitation on the East Coast Mountains in Mauritius. Internatn. J. Climat. 30: 11641177.
Swanepoel, L. H., Lindsey, P., Somers, M. J., Hoven, W. v. and Dalerum, F. (2013) Extent and fragmentation of suitable leopard habitat in South Africa. Anim. Conserv. 16: 4150.
Thompson, H. S. (1997) The breeding biology and ecology of the White-necked Picathartes Picathartes gymnocphalus Temminck 1825, in Sierra Leone. PhD thesis. Open University, UK.
Thompson, H. S. (1998) White-necked Picathartes Picathartes gymnocephalus: its ecology and conservation. In RSPB Conservation Review. Sandy, UK: RSPB.
Thompson, H. S. (2007) Family Picathartidae. Pp. 6069 in del Hoyo, J., Elliott, A. and Christie, D., eds. Handbook of Birds of the World. Vol. 12 Picathartes to tits and chickadees. Barcelona, Spain: Lynx Edicions.
Thompson, H. S. and Fotso, R. (2000) Conservation of two threatened species: Picathartes. Ostrich 71: 154156.
Tittensor, D. P., Walpole, M., Hill, S. L., Boyce, D. G., Britten, G. L., Burgess, N. D., Butchart, S. H., Leadley, P. W., Regan, E. C., Alkemade, R., Baumung, R., Bellard, C., Bouwman, L., Bowles-Newark, N., Chenery, A., Cheung, W., Christensen, V., Cooper, H., Crowther, A., Dixon, M., Galli, A., Gaveau, V., Gregory, R., Gutierrez, N., Hirsch, T., Hoft, R., Januchowski-Hartley, S., Karmann, M., Krug, C., Leverington, F., Loh, J., Lojenga, R., Malsch, K., Marques, A., Morgan, D., Mumby, P., Newbold, T., Noonan-Mooney, K., Pagad, S., Parks, B., Pereira, H., Robertson, T., Rondinini, C., Santini, L., Scharlemann, J. P. W., Schindler, S., Sumaila, U., Teh, L., van Kolck, J., Visconti, P. and Ye, Y. (2014) A mid-term analysis of progress toward international biodiversity targets. Science 346: 241244.
Weimerskirch, H., Prince, P. A. and Zimmermann, L. (2000) Chick provisioning by the Yellow-nosed Albatross Diomedea chlororhynchos: response of foraging effort to experimentally increased costs and demands. Ibis 142: 103110.

The importance of protected and unprotected areas for colony occupancy and colony size in White-necked Picathartes Picathartes gymnocephalus in and around Gola Rainforest National Park, Sierra Leone



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