I’ve spent the last couple of months in the Taita Hills in SE Kenya where I am studying the impacts of anthropogenic habitat degradation on bird functional diversity and composition. Specifically, I’m working in a sky island complex of massifs topped with remnant montane forests that form the northernmost extent of the Eastern Arc Mountains. The forest fragments on these hills are designated as Key Biodiversity Areas (KBA) and Important Bird Areas (IBA) because of high levels of endemism and biodiversity. This area is ideal for this research as it shows very high levels of historical habitat fragmentation and different degrees of degradation through various human land-uses.
I am starting with characterising the bird communities of the different forest fragments and the surrounding agricultural matrix by identifying bird species via point counts & AudioMoth sound recordings. This data will be combined with an existing traits database so that we can determine what functional roles are present (and to what extent) in each habitat.
Another approach that we’re using to try to understand how effective birds are at controlling pest insects is by using plasticine model “caterpillars”. The attack marks that are left behind help us to identify the levels of predation relative to habitat quality.
This lays the foundation for my next field season when we will be capturing birds to collect faecal samples which will be analysed using DNA metabarcoding. This will provide us with information on how birds’ diets are influenced by habitat quality and also allow us to quantify the ecosystem functions that birds perform – like controlling herbivorous insect pests and seed dispersal.