The relations between forest fragmentation and bird community body size and biodiversity and bird community body size.

Bachelor thesis Future Planet Studies, major biologie

ABSTRACT

Animal species with a larger body-size tend to have larger home ranges than small-bodied animals. Therefore it is likely that they are more affected by habitat fragmentation than small-bodied species. Body size of birds also seems to have a negative relation with species richness. This research has therefore looked into whether birds with a larger body-size are more sensitive to habitat fragmentation caused by forest fragmentation, than birds with a smaller body-size. Also the relation between biodiversity and community body mass was investigated. This was done by linking the community body-mass of birds at specific sites from the PREDICTS database in 14 different countries spread around the globe with the core area index (CAI) of these sites and the distance from these sites to the edge of a habitat supporting a high biodiversity (DEHHB). Of the 10 analyzed studies concerning the relation between CAI and community body size for three studies a negative relation was found, while the remaining seven indicated a positive relation. Of these 10 studies only three studies had a p-value lower than 0.05. These three studies did not correspond with the three studies for which a negative relation was found. Of the seven analyzed studies concerning the relation between DEHHB and community body size for three studies a negative relation was found, while the remaining four indicated a positive relation. None of these relations were significant. Therefore, it is concluded that no relation was found between CAI and community body mass as well as no relation between DEHHB and community body mass. Both these findings are in contrast with previous literature might be due to the fact that there was no consistent edge type in the analysed studies, also the limited size of this study and the lack of data could be a cause. It is recommended to obtain more data concerning bird species abundance and mean community body mass with a large amount of species per study, so more inclusive research can be conducted and to study areas which contain the same type of edge.