Retraction statement: 'Species distributions shift downward across western North America' by M.A. Harsch and J. Hille Ris Lambers

The above article, published online on 18 August 2014 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, Dr Melanie Harsch and Associate Professor Janneke Hille Ris Lambers, journal Editor-in-Chief, Professor Stephen Long, and John Wiley & Sons Ltd. The retraction has been agreed for the following reasons: a coding error affected the results and therefore invalidated the broadscale conclusions presented in the article. The article presented broad-scale patterns of species distribution shifts in response to recent climate change. Unfortunately, it has since been found that one approach used to account for sampling bias, the null model approach, was affected by the coding error. Following the identification of the coding error, we are therefore retracting the article. We thank Drs Adam Wolf and William Anderegg for bringing this issue to our attention.