A 250-year-old census has revealed islanders on St Kilda ate more than 1,600 seabirds every day.
The document is the earliest recorded list of the archipelago's population and was discovered by archivists among a hoard of clan papers.
The census lists 90 people living on the main island of Hirta on June 15, 1764 - 38 males and 52 females, including 19 families and nine individuals.
Further light is shed on the islanders' diet, with each resident said to eat "36 wild fouls eggs and 18 fouls" daily - an island-wide total of 3,240 eggs and 1,620 birds every day.
The 1764 census also includes the ancestors of the final five families to be evacuated from the archipelago, which lies 41 miles west of Benbecula, in 1930 - the MacQueens, Fergusons, Gillies, MacDonalds and MacKinnons.
Until now, the oldest known record of the population dated from 1822.
As the later document includes ages, it is now possible to track five residents of St Kilda who appeared on both censuses, 52 years apart.
The census was discovered among the papers of Clan Maclachlan during cataloguing by the National Register of Archives for Scotland (NRAS), the branch of the National Records of Scotland which holds historical papers held in private hands.
Alison Rosie, NRAS registrar, said: "This document sheds new light on the history of St Kilda and the families who lived there, and gives us an insight into their lives more than 250 years ago.
"Through it we can trace individuals back 50 years earlier than the next surviving census, and many of the people listed were the ancestors of the families who left the island in 1930."
Donald Maclauchlan of Clan Maclachlan said: "The document was found as part of a hoard of papers - around 13 large boxes. When I heard from Charlie Maclachlan of Maclachlan the younger that they had been found, I asked to see some of them and the first document I pulled out dated from 1590. I realised the time had come to call in the professionals."
He said a NRAS team took a year-and-a-half to catalogue the papers, including the St Kilda census.
The archipelago is the largest seabird colony in the north-east Atlantic with 600,000 nesting birds each year.
But the National Trust for Scotland (NTS), which owns the islands, recently warned that after century of growth bird populations are falling rapidly.
An NTS spokesman said: "It's very familiar that seabirds were part of the staple diet of the islanders and oil products and feathers from seabirds were a major part of the islands' economy.
"This new research underlines our previous knowledge of the people of St Kilda."