Robert Quirk aged 19 in 1881.
Assuming the age is more or less correct, there are two candidates in the 1871 census.

Michael, district 3, schedule 45, Bargarely
Robert Quirk, head, married, 55, farming 38 acres, Michael
Jane, wife, married, 50, Michael
John, son, unmarried, 22, stone hedger, Michael
Thomas, son, unmarried, 20, shepherd, Michael
Mary J, daughter, 12, Michael
Robert C, son, 9, scholar, Michael

In 1891 this Robert was living, unmarried with his widowered father and two siblings at Sartfield.
In 1901 Robert Charles is living unmarried with his unmarried brother, John, at Sartfield.

1871, Patrick, district 6, schedule 3, Old Road
William Quirk, head, married, 47, lead miner, Malew
Christian (?), wife, married, 41, Patrick
John, son, unmarried, 17, mine labourer, German
Margaret J, daughter, 14, German
Sage E, daughter, 12, German
William E, son, 11, German
Robert C, son, 9, scholar, Marown
Mary A, daughter, 8, scholar, Marown
Philip H, son 6, Marown
Thomas A, s, 1,Marown

I can not identify him in 1891/1901

I'm away from home at the moment so cannot check the above transcriptions against the fiche.