Figure 1

Density weighted box plot of the elevational ranges for 74 bird species inhabiting the south temperate Andes Mountains, Chile. The thick horizontal line within the box represents the median of each species, the boxes represent the first and third quartiles, vertical whiskers represent 1.5 * inter-quartile range (distance between the first and third quartiles), and the outlying points are plotted individually (points that lie outside of the whiskers). The green dashed line represents the average treeline elevation. See species codes in supporting information Appendix S1.