Figure 5. Predicted niche occupancy (PNO) profiles for the four clades of Pomatorhinus scimitar babblers.

Horizontal axes represent the Isothermality (Bio3 - the tolerance of diurnal temperature range divided by the annual temperature range, all multiplied by 100) parameter space divided into 50 equally spaced bins, while vertical axes denote the total suitability of the isothermality index of each species over its entire geographic range (see Methods). Specific epithets have been reduced to three letter codes for brevity. Taxa annotated by open triangles occupy Himalayan foothills, while open circles and open squares denote species occupying highlands at lower latitudes (Assam/Burma and Burma/Thailand, respectively). Overlapping peaks of PNO profiles indicate similar climatic tolerances, while the overall breadth of the profile denotes the degree of specificity in climatic tolerance. See also Figure S2 for PNO graphs of all 10 bioclimatic variables used in the niche modeling algorithm of the 4 Pomatorhinus clades and their constituent species.