 In general, the smaller forms occur in coastal mountains, intermediate birds in the Andes, and large, darker, forms breed on the tepuis.The largest of the tepui subspecies, "Z. c. perezchincillae", has grey underparts, and the rufous collar extends as a black band of freckles across the breast.This form might be separable as a distinct species, or it might just be a particularly distinct population due to genetic bottleneck effects.