After a morning sheltering inside from the pouring rain, it cleared and I drove down to Creag Meagaidh, the enormous national nature reserve that fills a watershed from Loch Laggan up to the named mountain. The sun shone nearly all the time despite billows of cloud to the south. The hills were blue, setting off the shining grey-green of the birches, the russet of the heather – the Ling just coming into bloom now – and the bright yellow-green of the mossy grass.

The Downy Birch is a stockier tree than the Silver Birch, tough enough to survive mountain winters, and home to a rich variety of lichens including Usnea beard lichens, bristly Ramalina, dark stringy Alectoria jubata (now renamed Bryoria fremontii), and various leafy Parmelia species that yield orange dyes used in Harris Tweed.

Large handsome caterpillars of the Northern Eggar Moth, the Scottish form of the Oak Eggar (Lasiocampa quercus), up to 3 inches (75 mm) long and nothing to do with oak trees, wriggled across the path, their rufous hairs warning off predators. They feed on Heather and Bilberry.

In every patch of damp grassland, Scotch Argus butterflies skittered, looking very dark in flight. They are hard to approach as they constantly chase each other off from their territories, but eventually I found one that stayed settled long enough to creep up to. Close up, the upper side is a rich brown, with red patches around the wing edges dotted with black circles that have white centres.

A few bumblebees, some of unfamiliar species, visited the Devilsbit Scabious (Scabiosa succisa) briefly. Large Syrphid hoverflies basked on the paths.

Further up the valley, a fine group of birches actually glittered in the bright sunlight, the water of the stream shining silver behind them.

A dead birch, stark against the sky, supported stout Birch Bracket polypores, handsomely whitish-grey above, yellow ochre below.

In the boggier patches, Bog Asphodel and Marsh Orchid flowered among the Bell Heather.

I turned the corner of the valley to see snow still lying in the deep, north-facing gullies on Creag Meagaidh, and the striking notch of the col that gives access to the mountain ridge.