What is historically the UK’s longest lasting patch of snow has disappeared for “only the eighth time in 300 years”.
Dubbed the Sphinx, the patch on remote Braeriach in the Cairngorms has melted away more frequently in the last 18 years.
Snow patch expert Iain Cameron said climate change was a likely factor.
According to records, the Sphinx previously melted fully in 1933, 1959, 1996, 2003, 2006, 2017 and 2018.
Before 1933, it is thought to have last melted completely in the 1700s.
The Sphinx had shrunk to the size of an A4 piece of paper in recent weeks before finally disappearing in mild weather.
Mr Cameron told BBC Scotland that historically the Sphinx was the UK’s “most durable” snow patch.
But he said: “That is being challenged because it is disappearing more often.”
Mr Cameron said warmer weather due to climate change “seemed to be the logical” explanation for the increased rate of melting.
He added that the conditions were affecting snowy areas high on other Scottish mountains including in the Ben Nevis range in Lochaber.
Aonach Beag, near Ben Nevis, also has a patch of snow that has often survived from one winter to another.
But Mr Cameron said: “What we are seeing from research are smaller and fewer patches of snow.
“Less snow is falling now in winter than in the 1980s and even the 1990s.”
Separately from Mr Cameron’s research, a report commissioned by Cairngorms National Park Authority and published last year said declining snow cover, and fewer days when it snowed had been observed on Cairngorm mountain since the winter of 1983-84.
