The male House Sparrow has a black bill in the breeding season and in summer.
In winter the male's bill is lighter in color.
Young males have a yellowish bill.
Females have a yellowish bill all year round.

1st & 2nd photo: A male. Washington Square Park, Manhattan, New York City, New York, USA, 30 October 2017
3rd & 4th photo: A female. Washington Square Park, Manhattan, New York City, New York, USA, 30 October 2017
5th photo: A male. Central Park, Manhattan, New York City, New York, USA, 5 November 2010