noun
russet sparrow; cinnamon sparrow
A small bird (Passer rutilans) found in East Asia. In Japanese, the name is usually written in katakana as ニュウナイスズメ.
ニュウナイスズメはスズメより少し小さい。
The russet sparrow is a little smaller than the tree sparrow.
春になるとニュウナイスズメが渡ってくる。
In spring, russet sparrows migrate here.
The common tree sparrow (Passer montanus), a familiar bird throughout Japan. ニュウナイスズメ is a different species with a more restricted range.
The name ニュウナイスズメ literally means 'palace-entering sparrow'. The origin is uncertain, but it may refer to the bird's habit of nesting in buildings or its association with human settlements.