Avian Persistence in Fragmented Rainforest

Abstract

What factors determine the persistence of species in fragmented habitats? To address this question, we studied the relative impacts of forest deterioration and fragmentation on bird species in 12 rainforest fragments in Kenya, combining 6 years of individual capture-recapture data with measurements of current captures and museum specimens. Species mobility, as estimated from species-specific dispersal rates, and tolerance to habitat deterioration, as estimated from change in fluctuating asymmetry with increasing habitat disturbance, explained 88% of the variation in patch occupancy among eight forest bird species. Occupancy increased with mobility and with tolerance to deterioration, where both variables contributed equally to this relationship. We conclude that individual-level study, such as of dispersal behavior and phenotypic development, can predict patterns of persistence at the species level. More generally, for conservation tactics to stand a high chance of success, they should include action both within sites, to minimize habitat deterioration, and across landscapes, to maximize dispersal.

Riparian corridors enhance movement of a forest specialist bird in fragmented tropical forest

“…6) provided by corridors (7)(8)(9)(10), but this has been difficult to achieve for small species, like birds, that move at landscape scales (6). More specific movement information from free-ranging animals is especially important for forest specialists, particularly understory insectivores, because this group appears to be most sensitive to the isolation effects of fragmentation (4,11,12). Both forested corridors and fencerows of individual, living trees have been promoted as landscape elements to facilitate the movement of birds and other forest dependent animals (11,13), but no studies of birds have directly measured movement in these habitats.…”

“…2), corridors have been widely advocated as a means to maintain biodiversity and ecological processes in fragmented landscapes (3,4). Several studies have demonstrated that target organisms occur in corridors (5), providing indirect evidence that they facilitate movement.…”

The effects of forest land use and fragmentation on White-throated Mountain Babblers <i>Kupeornis gilberti</i> a globally threatened bird species on the Obudu Plateau, southeast Nigeria

“…The highest distance between two forest patches was 920 meters ( Table 2), so that might be the reason why significant difference statistically was not found. Also the species has high mobility and the corridors observed in this study make it likely to survive in fragmented landscapes with low isolation distance (Lens et al, 2002;Thomas, 2000). Their densities decreased with an increase in isolation distance (Figure 2).…”

“…Lens et al (2002) found that bird occupancy in a forest patch increased with mobility and the tolerance to deterioration of the habitat.…”

Ecological Biogeography of West Usambara Mountains: A Study on the Influence of Abiotic Factors to Spatial Distribution of Plant and Animal Species

“…There are discoveries made on biological diversity for small mammals [4][5][6][7], larger mammals such as primates [8], carnivores [9], invertebrates [10], reptiles and amphibians [11], and birds [12][13][14]. The literature also indicates rich diversity of plants like angiosperms [15,16].…”