These little birds, Spice Finches (Lonchura punctulata), look very much the same as sparrows but are even smaller (11cm to the sparrows’ 15cm) and their coloration is somewhat different. Juveniles are plain brown above and below, while the adults have chestnut faces and a scale-like pattern on the belly feathers.
Both are actually exotics which are well established here and both are technically finches – not that we normally think of sparrows as such.
The Spice Finch, also known as the Scaly-breasted Munia or Mannikin (see note on Birdway), is native to tropical Asia, occurring from India and Sri Lanka east to Indonesia and the Philippines. It has been introduced into many other parts of the world and feral populations are established in the USA and Central America as well as here. Slater’s Field Guide says that in Australia it is resident in coastal eastern Australia, mainly from Sydney to SE Queensland “but spreading”.
The species seems to be well established around Townsville. On checking older photos in preparation for this post I found that I had photographed them along Ross River on three other occasions and on the Town Common. This small flock was feeding in parkland beside Ross River, Mundingburra, when I spotted them, taking to the long grass and then to a leafless tree when I approached too close for their peace of mind.