BRANTA — Nickson Otieno
Factors influencing diversity and abundance of farmland birds around Kakamega forest, Kenya
Institution: University of Nairobi (UoN), Kenya
Supervisors: Nathan Gichuki, Nina Farwig (Mainz University), Samiel Kiboi
Details: MSc 2008 (Completed)
Address: National Museums of Kenya, P. O. Box 40658 Nairobi, GPO 00100, Kenya. (March 2014) Email
Subject Keywords: Farm, structure; farmland, birds, assemblage
Species Keywords: farmland, passerines
Thesis online at https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2028.2011.01273.x/abstract
Abstract
Although it is clear that the farmlands neighbouring fragmented forests are utilized by some forest birds, it is not clear how birds in general respond to farmland habitat mosaic. An effort was made to determine how bird density and foraging assemblages were influenced by farm struc-tural characteristics and distance from forest edge. Thirty farms up to a distance of 12 km around Kakamega forest in western Kenya were studied. Farm structure entailed size, hedge volume, habitat heterogeneity, woody plant density, plant diversity and crop cover. Birds were sur-veyed using line transects and DISTANCE analyses and classified into six feeding guilds and three habitat associations. Size of farms increased away from the forest, as woody plant density, plant diversity, indigenous trees and subsistence crop cover declined. The most important farm structure variable was hedge volume, which enhanced bird species richness, richness of shrub-land bird species and insectivorous bird density (R= 0.58, P < 0.01). Bird density increased with tree density while indigenous trees were suitable for insectivores and nectarivores. There were very few forest bird encounters. Agricultural practices incorporating maintenance of hedges and sound selection of agroforestry trees can enhance conservation of birds on farmland, though, not significantly for forest species.
Publications
Otieno, N.E., Gichuki, N. & Farwig, N. 2011. The role of farm structure on bird assemblages around a Kenyan tropical rainforest. African Journal of Ecology 49: 410-417.