Integrating Open Access Geospatial Data to Map the Habitat Suitability of the Declining Corn Bunting (Miliaria calandra)

Abdulhakim Abdi

doi:10.3390/ijgi2040935

Abstract

The efficacy of integrating open access geospatial data to produce habitat suitability maps for the corn bunting (Miliaria calandra) was investigated. Landsat Enhanced Thematic Mapper Plus (ETM+), Shuttle Radar Topography Mission (SRTM) and Corine (Coordination of Information on the Environment) land cover data for the year 2000 (CLC2000) were processed to extract explanatory variables and divided into three sets; Satellite (ETM+, SRTM), CLC2000 and Combined (CLC2000 + Satellite). Presence-absence data for M. calandra, collected during structured surveys for the Catalan Breeding Bird Atlas, were provided by the Catalan Ornithological Institute. The dataset was partitioned into an equal number of presence and absence points by dividing it into five groups, each composed of 88 randomly selected presence points to match the number of absences. A logistic regression model was then built for each group. Models were evaluated using area under the curve (AUC) of the receiver operating characteristic (ROC). Results of the five groups were averaged to produce mean Satellite, CLC2000 and Combined models. The mean AUC values were 0.69, 0.81 and 0.90 for the CLC2000, Satellite and the Combined model, respectively. The probability of M. calandra presence had the strongest positive correlation with land surface temperature, modified soil adjusted vegetation index, coefficient of variation for ETM+ band 5 and the fraction of non-irrigated arable land.

Highlights

European farmland bird species and long-distance migrants continue to decrease at an alarming rate [1]despite the passing, in 1979, of the Council Directive 79/409/EEC on the conservation of wild birds, known as the “Birds Directive”
This study aims to better understand the habitat requirement of M. calandra in north-eastern Spain through the fusion of open access data derived from Corine land cover, Landsat and the Shuttle Radar
Explanatory variables in this study describe the biogeophysical aspects of the landscape and were used in statistical analysis to predict the occurrence of M. calandra at unsurveyed locations

Summary

Introduction

European farmland bird species and long-distance migrants continue to decrease at an alarming rate [1]despite the passing, in 1979, of the Council Directive 79/409/EEC on the conservation of wild birds, known as the “Birds Directive”. Northern and central European populations of the corn bunting (Miliaria calandra) have declined sharply since the mid-1970s [4], notably in Britain [13], Poland [14], Germany [15] and Ireland [16]. The declines of these species have been credited to detrimental land use policies, such as the Common Agricultural Policy (CAP) [1], that have been in effect in the European Union since the early 1960s. CAP promotes the maximization of agricultural productivity through the intensification of farmland; a process that results in monocultures, pesticide use and the eradication of uncultivated areas [17]

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