Browsing by Subject "abundance"

Urbanisation threatens species and biodiversity globally. Consequent habitat loss and habitat fragmentation force species upon one another, inevitably also increasing human-wildlife conflicts. Despite the situation growing dire for many organisms, studies also show species from a variety of taxa being able to adapt to urban environments. Most studies of primates’ ability to adapt to urban environments have been done on diurnal species. To my knowledge, the African lesser bushbaby (Galago moholi) is the only nocturnal primate in which this has been studied. To assess urban adaptability in another nocturnal primate, I present transect and recording data on the abundance of the white-tailed small-eared greater galago (Otolemur garnettii lasiotis) in an urban and rural environment in the biodiversity hotspot Taita Hills, Kenya. Sampling was done in Wundanyi town and Ngangao forest and the two locations were then compared by fitting a negative binomial as well as a Poisson model for recording and transect count data. Additionally, preliminary observations are made regarding behavioural and spectral acoustic adaptation, increased sociality, and colouration coupled traits. My results indicate O. g. lasiotis to be significantly more abundant in the town than in the forest. In the town, I observed a two-fold increase in total number of vocalizations and mean vocalization rate, and a seven-fold increase in total number of sightings and mean encounter rate, as indicated by recordings and transects respectively. This discrepancy in estimated abundance differences in location from transect and recording data (two-fold versus seven-fold) suggest that urban individuals vocalize less than rural individuals. The spectral profile of three vocalization types were studied and urban individuals exhibited significantly higher high frequencies in the clustered squawk vocalization. I found town dwelling individuals to be a part of a larger group or pair considerably more often than forest dwelling individuals. A dark morph, as opposed to a light morph, was significantly more frequently encountered in the urban location, whereas both morphs were encountered almost equally often in the rural location. In summary, O. g. lasiotis seems to be capable of adapting to an urban environment, as indicated by its’ greater abundance in the town than in the forest. My data suggest decreased vocalization rate, increased sociality, and colouration coupled traits being possible adaptations affecting O. g. lasiotis’ capability to inhabit an urban environment. Further research is required to draw conclusions on what factors and adaptations might allow for the high abundance of O. g. lasiotis in the town.