Your ancestor Donald was living next door to the family of Rory Campbell (who was dead in 1871 at the time of the census - he died in February of that year) and Neil Campbell who died in 1876.Rory and Neil were both the sons of Jeremiah Campbell of Barra. I believe Francis Campbell listed on 1871 was Roderick's son. Your Donald was likely their brother. These Campbells likely lived on the land of their father Jeremiah. The children of Jeremiah and his wife Anne (MacNeil) Campbell settled in the Big Pond, Middle Cape, Irish Cove, Red Islands areas.
Family Group Record for Darby Campbell and Ann MacNeil
Husband Jeremiah 'Diarmaid' 'Darby' Campbell Wife Ann MacNeil
Children 1 F Catherine Campbell Born date: (from Big Pond) Died Bef 1871 place: Spouse John MacNeil ( -Bef 1871) Abt 1815 - Cape Breton, Nova Scotia 2 M Malcolm Campbell Born date: (son of Dirmid Campbell of Green) Died Bef 1871 place: Spouse Mary MacLean ( -Bef 1871) 25 Nov 1819 - Barra, Scotland 3 M John Campbell Born date: (of Green, Barra, Scotland) Died Bef 1871 place: Spouse Mary Buchanan (Abt 1791- ) 21 Jan 1823 - Barra, Scotland 4 M Neil Campbell Born Abt 1804 Barra, Scotland Died 1 Mar 1876 Big Pond, Cape Breton, Nova Scotia, Canada Spouse Catherine 'Kitty' MacNeil (Abt 1816-1866) 5 F Mary Campbell Born Abt 16 Mar 1806 North Green, Barra, Scotland 6 M Rory Campbell Born Abt 1807 Barra, Scotland Died Feb 1871 Big Pond, Cape Breton, Nova Scotia, Canada Spouse Mary MacKinnon (Abt 1822- ) 7 F Catherine Campbell Born Abt 1808 Barra, Scotland Died 3 Jan 1876 Red Islands, Richmond, Nova Scotia, Canada Spouse Hector Campbell (Abt 1808- ) 8 F Christian 'Christy' Campbell Born 26 Oct 1808 Green, Barra, Scotland Died 25 Jan 1879 East Bay, Cape Breton, Nova Scotia, Canada 9 M Donald Campbell Born Abt 1810 place: Spouse Margaret MacKinnon (Abt 1811- ) 10 F Elizabeth Campbell Born 1811 Barra, Inverness, Scotland Died 25 Feb 1876 Big Pond, Cape Breton, Nova Scotia, Canada Spouse Jonathan 'Eoin Mor' MacNeil (Abt 1802-1882) Abt 1842