About Staff

In environments where human activity exerts a strong influence, the presence or absence of many living organisms is connected to land use. There is a difference, for example, between the living organisms that inhabit rural environments, where second-growth forests and paddy fields are abundant, and those that inhabit urban environments, where isolated forests are scattered about surrounded by residential neighborhoods. I have studied the ways in which avian species are affected by changes brought on by these kinds of human-made environments, and what differences in ecological functions arise as a result, focusing my attention on nutrient transport as nitrogen and phosphorus. For example, in Japan, the population of forest bird species in the fragmented urban forests I surveyed was greater than the population in the mountain region. As a result, the amount of excreted nitrogen and phosphorus mediated by bird feces in urban crow roosts were found to be dropped 70 to 100 times more than the amount of nitrogen and phosphorus in the mountain forests. Measurements of stable isotope ratio and carbon, nitrogen and phosphorus amounts in bird feces suggested that crows roosting in urban forests eat foods (e.g. garbage) found in residential area. In Indonesia, I have focused on the impact of changes in land use, such as the development of large-scale Acacia plantations, on the diversity of bird species. My aim is to demonstrate that decreases in the diversity of avian species can be mitigated via landscape management, which tries to conserve natural secondary forest within and around these plantations.