Researchers from The James Hutton Institute, Scotland’s Rural College, Community Development Lens and Community Land Scotland have all been gathering evidence of such increases in numbers.

The examples given include the populations in Colonsay and West Harris.

The organisations said the changes were influenced by young people choosing to stay or return to island communities.

They have released a joint statement, called the Islands Revival Declaration, to indicate the “green shoots” of population growth.

They said the population increase had still to manifest itself in official statistics, such as the Census.

Dr Calum MacLeod, Community Land Scotland’s policy director, said: “The Islands Revival Declaration rightly highlights local control of land and marine assets as a key driver of positive population change in some island areas. The challenge now is to ensure that public policy maximises opportunities for more of that local control to be exercised through community ownership and other means to enable the continuing sustainability of all our islands communities.”

Colonsay has experienced “modest increases” with 106 people in 1991, 113 in 2001 and 132 in 2011, according to Census figures. The groups said they expected the upward trend to continue into 2021.

In Harris, work by the West Harris Trust community group, which also includes building affordable homes, has been credited with increasing the population in that section of the island from 119 in 2012 to 151 in 2019.

The West Harris Trust has set a target of reaching a population of 170 by 2020.