Wigan Genealogy

looking for info on Nathan Molyneux born at the oak inn bellegreen lane ince in 1877. From his birth certificate i know his father was john Molyneux and his mother was rosanna. However aged three when the census was taken in 1881 he was listed as living with his Grandmother a mary jackson in kersley. I have been unable to trace what happened to his parents or find them on the census. If any one has nore information it would be greatly appreciated.