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. cunicularia → A. c. grallaria , B.
v. nacurutu → B. v. deserti , M. c. choliba → M. c.
decussatus , M. c. choliba → M. c. uruguaii , and M.
w. watsonii → M. 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.