Niche overlap and equivalence test
It was found that the niches did not overlap for the two taxa shown by
very low score of Schoener’s D and Hellinger’s I niche similarity
metrics. The score were 0.025 and 0.068 respectively representing almost
nil overlap of the range of the species. Since the range do not overlap
these species could most likely be treated as two separate species. But
further genetic study is needed to truly ascertain the taxonomic status
of the species. The Indus dolphin seems to have significantly diverged
from its ecological niche as it separated from Ganges River Dolphin.
Likewise, the niche identity test has shown that the calculated niche
overlap of the pair are outside the 95% confidence interval of the null
hypothesis (p-value = 0) (Figure 3). This confirms the separation of the
two species. Hence, the niches of the two species are not equivalent.