"I have always kept travel diaries; especially when travelling alone. It releases the urge to tell someone about what you've seen or experienced. In my case, of course, diaries usually double up as sketchbooks.

The following sketchbook extracts are from a diary I kept during an expedition to the Shetland Islands back in 1985. The purpose of the expedition was to trap and ring seabirds for scientific study. Birds come to no harm during ringing and provide invaluable data vital to an understanding of their breeding biology and conservation.

By day it would be colonies of gulls and terns, or the gentle-looking Fulmars – Maalies as they are called in Shetland. And most nights would be spent in some sheltered bay in the brief, silvery darkness off Shetland’s ‘simmer dim’, playing the recorded songs of Storm Petrels to entice them to our mist nets. Enigmatic seabirds, capable of weathering the fiercest ocean storms, they return to their breeding colonies among the rocks and scree only under cover of darkness.

The final highlight of the expedition for me was an overnight stay, alone, on the island of Mousa where nearly 7,000 pairs of Storm Petrels nest in the walls of an Iron Age broch (stone tower)..."

From top left to bottom right: nesting Arctic Skuas keep a sharp eye out for potential threats, so approach with caution. Shags on a rock make interesting shapes for drawing. Juvenile gulls enjoy the chance to lounge about and bathe. An incubating Kittiwake on a cliff-side ledge.

"Mousa at last. The broch loomed larger and larger still as I approached. Shaped like one of those whisky glasses with a slight waistline. I hadn't known what to expect and was delighted to find that it had a door....with a gate.... that opened!

Inside it was like being at the bottom of an enormous well. Downstairs something was shuffling about. A Storm Petrel has wandered out of its crevice. I picked it up; it had a ring on. I fancied I recognised the number as one of ours, but I would have to wait to find out. I put it back in its hole. Strange to imagine how much life the silent place must hide, waiting for the night...

I retreated outside where the action was. Dozens of petrels were flying around and around. Occasionally one would almost fly into my face. Once or twice they'd collide in the air with a soft thud..."

From top left to bottom right: nesting Fulmars. A sketch of bathing Bonxies. Adult Puffins take a rest from carrying food to their young in burrows. Studies of Storm Petrels observed at the Mousa broch.