Mark Cocker planted his first country diary in the Guardian in autumn 1987, watching a jay bury acorns near Norwich. Thirty-nine years and 1,000 columns later, some of those acorns are mature oaks, and Cocker is the longest-serving diarist on the world's oldest column in an English-language newspaper — a form that began in 1904 with Thomas Coward, a retired textile bleacher from Cheshire. The country diary runs to just 360 words. Cocker compares it to a haiku: you awaken the subject from dormancy, drive straight into the theme, and — if the craft holds — link the observed moment to something larger. "You have a single shaft of light and, if you can, you excavate its relationship to the other parts," he says. "It's that connection between the part and the whole, the moment and the universal, which is the trick of the diary." He estimates it took him a full decade to master the form. His new book, The Nature of Seeing, collects recent diaries alongside new essays on how we might experience nature more fully. Cocker points to the surprising density of literary greats who also kept wildlife passions — Margaret Atwood, Vladimir Nabokov — arguing that close observation of the natural world is a discipline that benefits all writing. The book includes a striking passage about Inuit fishers who navigated home through fog by recognising subtly different patterns of snow bunting songs corresponding to invisible sections of coastline. "That is the level of attention to the living world which we've lost and need to recapture," Cocker says. The ecological context has shifted enormously around the column. On his latest visit to Flint Clough in the Peak District — where he first marvelled at rare birds aged 12 — Cocker found the cuckoo, golden plover, ring ouzel and twite of his boyhood replaced by buzzards, peregrines, marsh harriers and red kites. Some species gained, others vanished. The twite is now virtually extinct in England. The diary has become, in Cocker's words, "a repository for a sense of the impending crisis which assails all life." Cocker's path to the column was not literary-establishment standard. Before writing, he worked as a refuse collector, road sweeper, potato picker, and — as a penniless student — posed nude for the local art college. He was the first in his family to attend university, studying English while working as a warden at Holkham national nature reserve. His break came when a conservationist friend wrote to the Guardian complaining about inconsequential diaries about cricket matches, demanding the paper "get its boots and hat and coat on, and get out into the wild." Today the diary has about 30 contributors spread from Cornwall to the Cairngorms — farmers, scientists, a vicar, a thatcher, a forager. Editor Paul Fleckney calls Cocker "a gift to the diary," citing his combination of hyper-detailed knowledge, bigger-picture vision, and what amounts to a rare kind of indefatigability. Between Cocker and the legendary Lakeland diarist Enid Wilson, the two have covered a span of 76 years. Cocker is convinced the form's moment has arrived precisely because its modesty is now a philosophical asset. "The intensifying nature of capitalism, the rise of the right, migration, climate change, drought, starvation, overpopulation — everything is to do with one meta-story, and that is our relationship with the rest of life," he says. The diary, at 360 words, has become a surprisingly capacious vessel for that idea.