Difference between male and female Java Finch/ Java Sparrow 

Java sparrow. The Java sparrow (Lonchura oryzivora), also known as Java finch, Java rice sparrow or Java rice bird,
A small, plump finch with a very thick pink bill. The black head and white cheek patch are distinctive. Juveniles have a similar color pattern but are grayer. Social; forages in flocks and roosts communally. Forages in rice fields, grasslands, meadows, and urban and suburban areas (in introduced range). Call consists of one or more musical chirps. Native to the Indonesian islands of Java and Bali, where now quite rare. Introduced widely across the globe including India, Philippines, Venezuela, Puerto Rico, and the Hawaiian Islands.
Kingdom:AnimaliaPhylum:ChordataClass:AvesOrder:PasseriformesFamily:EstrildidaeGenus:LonchuraSpecies:
L. oryzivora
Binomial nameLonchura oryzivora
(Linnaeus, 1758)
Synonyms
Loxia oryzivora Linnaeus, 1758
Padda oryzivora (Linnaeus, 1758)
(Wikipedia/Ebird)