Chocolate self (wild-type)
A variant of Society finch (Lonchura striata domestica)
Representative Society finchphoto — a dedicated image of this exact morph isn't available yet.
The base self-colored bird in solid dark chocolate-brown, closest in appearance to the wild Bengalese/munia ancestry from which the domestic society finch was derived.
Keeper tips for this variant
Hardiest of the color forms and the textbook foster parent — keep a few self-colored pairs on hand to foster eggs of fussier estrildid finches.