The effect of 3-dimensional habitats and microclimate changes due to forest degradation on the ranging habits and activities of Sumatran orang-utans (Pongo abelii).
Start date: 21 August 2016
The effective protection of tropical forests requires the development of methods that can rapidly assess tropical forest structure, and relate this to habitat quality for keystone species, like primates. Whilst the effect of historical forest degradation on wide-ranging mammals such as primates may be marginal in terms of reduced habitat, changes in forest structure alter the ranging behaviour and cognitive processes of primates foraging for dispersed food resources. Forest degradation also disturbs tropical forest canopy structure, causing microclimate changes in degraded areas. These changes can drastically alter how and when primates use disturbed areas of forest. Using Unmanned Aerial Systems (UASs) and microclimate data loggers, this study uses innovative, cost-effective means to collect geospatial data on tropical forest structure and microclimate across a gradient of disturbance and links these measurement to habitat requirements for Sumatran orang-utans (Pongo abelii). This study relates over 6000 hours of orang-utan observational and ranging data to 3-dimensional forest structure, temperature and humidity data collected over an area of 10km2 in Sikundur, within the Gunung Leuser Ecosystem, Northern Sumatra. Initial results indicate that the altered structural complexity of degraded forests and the subsequent microclimate changes directly influence the locations of certain behaviours, not only reducing the habitat available to this critically endangered ape, but also disrupting the Sumatran orang-utans’ complex social system.