Scaly-breasted Munia

Forms of Scaly-breasted Munia.  Based on plumage coloration and patterns, the Scaly-breasted Munia appears to consist of three distinct forms or species, but the evidence points to the conclusion that it is a single species with a spectrum of appearances that intergrade into one another in zones of overlap.

The subspecies most widely considered separable from the rest is the nominate punctulata, “Checkered Munia,” of the Indian subcontinent—it has the most brightly colored upperparts, boldest underparts pattern, and nearly rectangular scaling that does not extend to the undertail coverts.

At the opposite end of the spectrum, the Chinese, Philippine, and Southeast Asian “Spotted Munia” (yunnanensis, topela, and cabanisi) shows duller shades of brown above and below, and the underparts pattern consists of scales that are rounded or angular, with spots or chevrons in their centers, and which extend to the undertail coverts.

The remaining subspecies (provisionally “Scaled Munia”) combine features of “Checkered” and “Spotted.”  In coloration, they resemble “Spotted” (with some that appear intermediate between “Checkered” and “Spotted”), whereas the patterns of their scaling resemble that of “Checkered.”  This group includes two Southeast Asian subspecies (subundulata and fretensis) and all of the strictly Indonesian subspecies (nisoria, sumbae, blasii, particeps, and baweana).  In these populations, whose natural range stretches from Bhutan south through western Indochina and the Malay Peninsula to eastern Indonesia, most adults look like a muted version of the “Checkered Munia.”  They appear to intergrade with both “Checkered” and “Spotted” in the zones of contact.

In sum, the variation of appearances within “Scaled Munia” suggests that it represents the central “stem” of L. punctulata, and that the “Checkered” and “Spotted” are regional branches that are in the process of diverging from it.