PARENT SESSION
Organized Oral Session 28: Ecological processes important in the responses of bird populations to environmental change driven by agriculture
Organizer(s): K Norris, E Chambers, and J Vickery
Wednesday, August 10, 8:00 AM - 11:30 AM, Meeting Room 511a, Level 5, Palais des congrès de Montréal

Using process-based models to predict how bird populations might respond to environmental change driven by agriculture.

Norris, Ken^*,1, ¹ CAER, University of Reading, Reading, United Kingdom

ABSTRACT- Recent analyses clearly show that agriculture is the most serious threat to avian biodiversity worldwide. In Europe, agricultural intensification over the last 30 years has caused widespread declines in biodiversity, and restoring this past damage is central to agri-environment policies. However, agricultural land-use is dynamic, responding to a broad array of drivers, including socio-economic and environmental policy, and the introduction of new technology. How can we predict how bird populations might respond to these changes? We use seed-eating bird populations as a case study to illustrate a more general approach to this problem. We construct a mechanistic model that describes trophic interactions between land-use, food (seeds) resources and bird populations. We show that this model is effective at describing the spatio-temporal distribution of birds across an agricultural landscape. We then illustrate the application of the model to scenarios of future change based on the introduction of genetically modified (GM) crops, an extremely contentious issue in Europe. The model suggests contrasting effects for different groups of birds depending on their ecology. Short-term impacts appear negligible, whereas long-term impacts could be more damaging to specific populations depending on ecological conditions. Mechanistic models based on relatively simple ecological theory could provide important insights into how populations might respond to future environmental change.

Key words: Agricultural change, Predictive modelling, Ecological mechanisms, Farmland birds