Bird assemblages in isolated Ficus trees in Kenyan farmland

Abstract

Over the last few decades a rapid and extensive conversion of tropical forests to agricultural land has taken place resulting in mosaics of fragmented forest patches, pastures and farmland. While the effects of forest fragmentation on biodiversity have been intensively studied within the remaining forests, relatively little is known about the biodiversity in tropical farmland (Daily et al. 2001, Pimentel et al. 1992). Frugivorous birds are an important group of species in tropical farmland ecosystems. Frugivorous birds are significant seed dispersers and can play a prominent role in transporting seeds into disturbed areas and setting the stage for the regeneration of these systems. Isolated fleshy-fruited trees in agricultural landscapes have been shown to attract birds, leading to an increased seed rain and seedling establishment under their canopies (Carrière et al. 2002, Duncan & Chapman 1999, Guevara et al. 1986, 2004; Slocum & Horvitz 2000).

Isolated Ficus trees deliver dual conservation and development benefits in a rural landscape

“…Furthermore, if the areas under isolated Ficus trees are well managed, they are likely to provide important resources for local households over long timescales, aligning conservation and development objectives through community resource management (Hutton and LeaderWilliams 2003;Adams et al 2004;Martin et al 2009). As the cost of reducing grazing and vegetation clearance under Ficus trees is low (Barnes et al 2014), and as Ficus trees occur in rural landscapes across the tropics (Slocum 2001;Guevara et al 2004;Eshiamwata et al 2006;Caughlin et al 2012), the conservation of Ficus trees and the plant communities associated with them could yield low-cost improvements to human welfare on a global scale.…”

Biodiversity, Species Interactions and Ecological Networks in a Fragmented World

“…Thus, agroecosystems with a diverse habitat structure can have at least some capacity to compensate for forest loss. Indeed, several frugivorous bird species use native and exotic fruiting trees in the farmland around the same forest, increasing seedling establishment (Berens et al, 2008;Eshiamwata et al, 2006), suggesting the matrix can aid fragment regeneration and restoration (Fisher et al, 2010). Further, bee diversity is higher than in the nearby forest, so the farmland may even act as a 'pollinator rescue', supporting pollination services inside the forest (Hagen and Kraemer, 2010).…”

Bird diversity and seed dispersal along a human land-use gradient: high seed removal in structurally simple farmland

“…Farwig et al 2006;Cordeiro and Howe 2003;Kirika et al 2008a, b;Herrera and García 2009) or studied isolated trees within the farmland (e.g. Eshiamwata et al 2006;Carrière et al 2002;Slocum and Horvitz 2000;Duncan and Chapman 1999). So far, no study has investigated interactions between birds and fruiting plants along the whole human land-use gradient ranging from forest to structurally complex and simple landscapes.…”