Testing alternative hypotheses for evolutionary diversification in an African songbird: Rainforest refugia versus ecological gradients Kirschel, A. N.; Slabbekoorn, H.; Blumstein, D. T.; Cohen, R. E.; de Kort, S. R.; Buermann, W.; Smith, T. B. Evolution 65(11), 3162–3174, 2011. Published Work Visit Site Social media impact badge provided by Altmetric