PhD Thesis
The Saadani-Pangani ecosystem form part of the east Africa coastal forests ― and these forests, sitting along the coast of eastern Africa appears as small dotted patches but their biodiversity value is remarkably high. For example, they host about 4,050 species of vascular plants with 43% of them being endemic. The forests are either protected in forest reserves, or occurs in lands under private ownership. However, these forests have traditionally been impaired by suppression from human deleterious effects including forest clearing for subsistence agriculture and extensive livestock grazing. These disturbances cause habitat fragmentation which influence birds, including restricting dispersal of forest specialist species, for example. Therefore, this research was designed to assess the population status and genetic characteristics of forest dependant birds within fragmented forests in the Saadani-Pangani ecosystem, Tanzania. Two species, a forest specialist and a forest generalist were used as models. Specifically the research intended to: establish occurrence and population density; determine habitat preference; examine gene flow; and determine the effects of forest patch size and isolation on occurrence and abundance of the study species. Various techniques were used to collect data for achieving the objectives including line transects survey, mist netting, and laboratory analysis of molecular data to determine genetic makeup of individuals. Moreover, a number of methodologies were opted to analyse the data, including habitat modelling in Presence Program, density estimation using Distance Program, and forest patch size analysis using Quantum GIS software. Results showed that, the occurrence expressed as occupancy probability, and population density of the forest specialist species were higher in undisturbed habitat. On the other hand, the trend in occupancy probability, population density, and habitat preference of the forest generalist species opposed that of the forest specialist one. However, the genetic characteristics and gene flow of the forest specialist species did not differ among forest fragments. The findings under this research has provided useful information on statutes of forest specialist and generalist birds demonstrating their chance of persistence within fragmented habitat in the study system.
SUA-VLIR