Title: Integrating open-access geospatial data to map habitat suitability of the declining corn bunting (Miliaria calandra) in Catalonia, Spain.
Abstract: Twenty-five years after the implementation of the Birds Directive in 1979, Europe’s farmland bird species and long-distance migrants continue to decrease at an alarming rate. Farmland supports more bird species of conservation concern than any other habitat in Europe. Hence, it is imperative to understand farmland species’ relationship with their habitats.
This study uses the corn bunting (Miliaria calandra) as a test species in evaluating the efficacy of open access geospatial data to produce habitat suitability maps for use in conservation planning. Additionally, due to the limited availability of funds, only free and open source software were used. Landsat ETM+, SRTM and Corine land cover dataset for the year 2000 (CLC2000) were processed to extract explanatory variables, which were then divided into three groups; Satellite (ETM+, SRTM), CLC2000, and Combined. A logistic regression model was built for each group and predictive accuracy of each model was evaluated using cross-validation by randomly selecting 70% of the presence points as a calibration dataset while the remaining 30% for validation. Models were evaluated using area under the curve (AUC) of the receiver operating characteristic (ROC). All three models resulted in AUC values that were above the random model threshold of 0.5, which indicated that selected variables have an effect on corn bunting habitat selection behavior. The AUC values were 0.65, 0.72 and 0.88 for the CLC2000, Satellite and the Combined Model, respectively. The corn bunting had a strong positive correlation with land surface temperature, modified soil adjusted vegetation index, coefficient of variation for ETM+ band 5, and the non-irrigated arable land metric. The fusion of open-access data from different sources is a viable method in producing models that reflect species’ habitat preference. This not only aids in the identification and maintenance of important habitats as the Bird Directive stipulated but could also identify trends in bird numbers.
Funding: This work has been supported by the European Commission, Erasmus Mundus Program, International Masters in Geospatial Technologies, project no. 2007-0064.
Duration: 09/2009 – 02/2010
Output: Under review at International Journal of Applied Earth Observation and Geoinformation
