Potential distribution of Aquila chrysaetos in Mexico: Implications for conservation

Abstract

The golden eagle ( Aquila chrysaetos) has been poorly studied in Mexico. Even though it is listed as threatened in this country, partly because of habitat fragmentation and direct persecution, little is known of its distribution. We assessed the potential distribution of this species in Mexico using ecological niche modelling (ecological niche factor analysis, artificial neural network, genetic algorithm for rule-set production, environmental distance, support vector machine, MaxEnt) and the weighted average ensemble method. The models were evaluated using the area under the curve of the receiver operating characteristics. We applied a threshold of 50% probability to obtain high-suitability areas and considered marginality and specialization calculated by ecological niche factor analysis and the most important variables to the model. We assessed and evaluated the percentage of high-suitability area occurring in all Mexican natural protected areas. The performance of the ensemble model was high (area under the curve = 0.93) and the most important variables contributing to the model were grasslands and tree cover percentage. The resulting high-suitability area is considerably fragmented, it comprises 16% of the country and just 8% of it is located in natural protected areas. We propose some urgent actions and conservation measures to face the main problems that are threatening the species in Mexico.