Scaly-breasted Munia, Lonchura punctulata

Scaly-breasted Munia
This species, native to Asia,  had various names, including Nutmeg Mannikin, Spotted Munia,
and Spice Finch.
It is a popular cage bird and frequent escapee, with wild populations
in several warm-weather areas in North America. It is recognized as an established wild species
in Southern California, but reports of wild birds in the state north of San Luis Obispo County
have not yet been numerous enough to justify treating the species as established in the wild
there. Nonetheless, there are many reports of these birds, including juveniles, in the area
around Almaden Lake in southern Santa Clara County where this bird was photographed;
see here . Birds of this species roost as well as nesting in their nest structures, so observation
of one carrying nest material, as above, is not in itself enough to establish actual breeding.
See Restall, Munias and Mannikins (Yale U. Press, 1997). 

Scaly-breasted Munia
The same bird as the one shown above. The sex of Scaly-breasted Munias cannot
be reliably determined by appearance.