Subspecies’ niche analysis
The results of the similarity tests between conspecific subspecies are summarized in Supplementary material A, Appendix 1, Fig. F. We found niche overlap values significantly lower than expected from a null model distribution for all the pairwise comparisons. Consequently, we reject the null hypothesis of niche identity for all pairs, suggesting that in all cases niches are not identical to one another.
Our background tests yielded a more complex scenario (Supplementary material A, Appendix, 1 Fig. G). The observed values of D andI usually lied below the corresponding null distributions; hence, differences are bigger than expected by chance. However, we were failed to reject the null hypotheses of the background similarity tests when contrasting A. c. cuniculariaA. c. grallaria , B. v. nacurutuB. v. deserti , M. c. cholibaM. c. decussatus , M. c. cholibaM. c. uruguaii , and M. w. watsoniiM. w. usta , with arrows indicating the directionality of the comparison: the first subspecies against a randomized background derived from the second one. However, the Dand I metrics of the respective complementary comparisons fell below their corresponding null distributions, indicating that these were more different than expected by chance, hence leading us to reject the null hypothesis that their niches are similar.