The end of 2015 saw another great article published. This article, published by Noam Levin, Salit Kark and David Crandall assesses human presence beyond populated areas through the use of social media.
Complete reference: Levin, N, Kark, S & Crandall, D 2015, ‘Where have all the people gone? Enhancing global conservation using night lights and social media’, Ecological Applications, vol. 25, no. 8, pp. 2153-67.