Skip to content

Research at St Andrews

Changes in densities of Sahelian bird species in response to recent habitat degradation

Research output: Contribution to journalArticle


William Richard Lawrence Cresswell, JM Wilson, J Vickery, P Jones, S Holt

School/Research organisations


Habitat loss in the Sahel region of West Africa has been pronounced, due to anthropogenic effects and (potentially) climate change. Although strong links have been found between conditions in the Sahel and subsequent breeding populations of certain Palaearctic migrants, the effects of these fluctuations upon Afrotropical species are unknown. We repeated bird censuses (Dec 1993 to Jan 1994, Dec 2001 and Dec 2002) at Watucal Forest Reserve, northern Nigeria, an area of rapidly degrading Sahelian woodland. We predicted declines in the abundance of woodland bird species with deforestation. For the purpose of setting up an experimental control, we also repeated bird censuses in adjacent farmland habitats that had already been deforested by the first census period: we predicted no change in abundance of farmland bird species. Tree density at Watucal decreased significantly by 82% over the eight-year period. The number of birds counted per point, the total number of species recorded per point, and the Shannon diversity index, all declined significantly in Watucal, but there was no significant change in adjacent farmland. Of those species that were reasonably abundant in either census period, 22% (n = 41) at Watucal showed a significant change in abundance between periods: all of these species showed a decline. In contrast, only 4% (n = 23) showed a significant change in abundance (a decline) on farmland. Of the seven species that disappeared from Watucal between periods, 100% were classified as broadly woodland species and, of the eight species that were only recorded in 2001/02 at Watucal, 63% were classified as scrub or open species. Given that Watucal is a protected area, the degree of deforestation and concomitant changes in bird abundance suggest that the Sahel is likely to be undergoing major changes in bird diversity.



Original languageEnglish
Pages (from-to)247-253
Number of pages7
Issue number2
Publication statusPublished - Jun 2007

    Research areas


Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. Conservation research capacity in sub-Saharan Africa is improving, although only in a few countries

    Pototsky, C. & Cresswell, W., 9 Jan 2020, (Accepted/In press) In : Oryx.

    Research output: Contribution to journalArticle

  2. A fruit diet rather than invertebrate diet maintains a robust innate immunity in an omnivorous tropical songbird

    Nwaogu, C. J., Galema, A., Cresswell, W., Dietz, M. W. & Tieleman, B. I., 3 Jan 2020, In : Journal of Animal Ecology. Early View

    Research output: Contribution to journalArticle

  3. FragSAD: a database of diversity and species abundance distributions from habitat fragments

    Chase, J. M., Liebergesell, M., Sagouis, A., May, F., Blowes, S. A., Berg, Å., Bernard, E., Brosi, B. J., Cadotte, M. W., Cayuela, L., Chiarello, A. G., Cosson, J. F., Cresswell, W., Dami, F. D., Dauber, J., Dickman, C. R., Didham, R. K., Edwards, D. P., Farneda, F. Z., Gavish, Y. & 22 others, Gonçalves-Souza, T., Guadagnin, D. L., Henry, M., López-Baucells, A., Kappes, H., Mac Nally, R., Manu, S., Martensen, A. C., McCollin, D., Meyer, C. F. J., Neckel-Oliveira, S., Nogueira, A., Pons, J-M., Raheem, D. C., Ramos, F. N., Rocha, R., Sam, K., Slade, E., Stireman, J. O., Struebig, M. J., Vasconcelos, H. & Ziv, Y., Dec 2019, In : Ecology. 100, 12, 1 p., e02861.

    Research output: Contribution to journalArticle

  4. Weak breeding seasonality of a songbird in a seasonally arid tropical environment arises from individual flexibility and strongly seasonal moult

    Nwaogu, C. J., Tieleman, B. I. & Cresswell, W., Jul 2019, In : Ibis. 161, 3, p. 533-545 13 p.

    Research output: Contribution to journalArticle

Related by journal

  1. Densities and population sizes of raptors in Uganda’s conservation areas

    Pomeroy, D., Kibuule, M., Nalwanga, D., Kaphu, G., Opige, M. & Shaw, P., 16 Jan 2019, In : Ostrich. 90, 1, p. 25-36 12 p.

    Research output: Contribution to journalArticle

  2. Managing human disturbance: factors influencing flight-initiation distance of birds in a West African nature reserve

    Braimoh, B., Iwajomo, S., Wilson, M., Chaskda, A., Ajang, A. & Cresswell, W., 2018, In : Ostrich. 89, 1, p. 59-69 11 p.

    Research output: Contribution to journalArticle

  3. The continuing lack of ornithological research capacity in almost all of West Africa

    Cresswell, W., 2018, In : Ostrich. 89, 2, p. 123-129 7 p.

    Research output: Contribution to journalArticle

Related by journal

  1. Ostrich (Journal)

    Will Cresswell (Reviewer)
    10 Nov 2017

    Activity: Publication peer-review and editorial work typesPeer review of manuscripts

ID: 391828