Navigating fragmented tropical landscapes; understanding how forest fragmentation affects bird behaviour

Over the last century much of the tropical forest biome has been converted from continuous tracts of undisturbed forest to complex human-modified landscapes composed of degraded primary forest fragments, secondary forest, pasture and agricultural land1,2. In contrast, <10% of the tropical forest biome is protected within strict reserves3. Consequently, the long-term conservation of tropical forest biodiversity is increasingly dependent on whether fragmented, human-modified landscapes can support viable populations of forest species2,4 and the extent to which landscape dynamics alter species behaviour and interactions5,6.

Previous studies of birds in fragmented forest landscapes describe the presence and abundance of species but fail to explain why we see certain species persisting in fragments while others are only found in continuous forest7. The answer likely lies in how animals use their spatial environment and their capacity to move among forest fragments to meet dietary, roosting and reproduction needs, while avoiding predation8. Currently, we know little about how birds disperse in undisturbed habitats let alone how movement patterns shift with habitat fragmentation. We predict that species life-history and morphological traits will interact with landscape composition to determine


dispersal among forest fragments9. For example, animal species with large dispersal distances may be less affected by fragmentation than poorly dispersed species with small home ranges.

Fig1: Forest fragments in the Cerro Cama landscape.
In this project we will work in well-characterised landscapes in central Panama, where we will tag birds with state-of-the-art radio tracking devices capable of recording their movements within and between forest fragments. These devices represent the latest in animal movement monitoring technology and will provide us with unprecedented detail on individual bird movements. We will integrate these novel data with existing knowledge of the landscape, and bird functional and life-history trait data to:
1. Describe how the movement patterns of birds (from a subset of species) shift from forested to
fragmented landscapes.
2. Understand how movement patterns are mediated by landscape structure and species traits.
3. Quantify the functional connectivity of human-modified landscapes for birds, and identify how this shapes species composition of individual forest fragments.