Fourth Hand Wing Index Quartile (IMAGE) University of Copenhagen - Faculty of Science Caption Birds with longer and pointier wings dominate temperate areas, like Europe and North America (red). On the contrary, birds with smaller and more round wings are dominating in tropical areas, like South Africa and south America (Blue). Credit Figure: Kennedy, et al, 2016. Usage Restrictions Kennedy, J. et al 2016 License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.