Nature Studies by Michael McCarthy: Reason to be cheerful. It's rook-building time It sometimes seems a pity that there are only four official seasons. Golden October is a world away from sodden November, but they're still lumped together in autumn. And this period at the moment, mid-March, is a sort of in-between time, with winter officially gone and spring officially here, but it doesn't really feel like either. It's a waiting time, when things are coming, but haven't yet arrived. I got a sense of what you might call it last week when I went to the Norfolk coast in search of small wintering songbirds, the uncommon feathery bundles you can find hopping along that shoreline in the cold months, which breed somewhere else far away. I was hoping there were still some around, in particular twite (finches which breed in the Pennines), shorelarks (which breed in Scandinavia) and snow buntings (a few of which breed in the Scottish Highlands, although most nest high in the Arctic.) I ended up at Holkham, the sweeping beach backed by pine-clad dunes which Gwyneth Paltrow walks towards in the closing scene of Shakespeare In Love - that unforgettable metamorphosis from the end of one play, Romeo and Juliet, into the beginning of another, Twelfth Night. You may remember that Paltrow's character, Viola de Lesseps, who has just played Juliet, gives to her lover Shakespeare, as a farewell memento, the idea of creating the Viola who is Twelfth Night's spirited heroine, and whom we first meet shipwrecked on a beach, distraught to think that her brother has been drowned. (And I have to say, in passing, that Viola's first five words are a supreme example of Shakespeare's way with cadence, his ability to impart feeling to the simplest phrase. Viola says, "What country, friends, is this?" Which to me has always ached with sadness. But imagine putting the "friends" somewhere else in the sentence, as the rest of us would probably do. At the beginning, we would have: "Friends, what country is this?" Which is merely commanding; or at the end, we would have: "What country is this, friends?" Which is merely curious. Got to hand it to the old boy, haven't you?) Being on Viola's beach, so to speak, was a pleasure in itself, and it was buzzing with birds, especially skylarks and parties of finches like linnets, but of twite and shorelark there was no sign, although a splendid snow bunting dropped down right in front of me. By then, however, my thoughts were filled with another bird entirely: the rook. One of the benefits of getting out of London is the chance to see rooks. Although the capital is filled to the brim with carrion crows, their rook cousins these days avoid the city centre as it is now too far from the ploughed fields in which they forage. But as soon as you get into the Home Counties, rooks start appearing, as they did when I got to the South Mimms service area on the junction of the M25 and the A1: there's a rookery in the trees surrounding the car park. And what are they doing? Right now, they're building their nests. There's something immensely uplifting about rooks nest-building in their colony, a great group of them cawing continuously: it's almost as if they're on a building site, whistling. The contrast with the solitariness of the carrion crow is striking. I know it's hopelessly unscientific, I know it's anthropomorphising, but I look at a carrion crow, at that sinister lone black figure - especially in the city - and I think: "serial killer." I hear the neighbours being interviewed after the arrest: "Crow? Kept himself to himself, really. Bit of a loner. Whereas rooks - rooks which do everything together, foraging and feeding, roosting and sleeping, and now carrying twigs back to the rookery - seem full of the high spirits of cooperative enterprise. All the way to north Norfolk, there were bustling rookeries, building sites in the trees - I stopped to look at several - and they were full of birds which seemed to be calling out to each other, "Up a bit! Up! Now left a bit! Left! And eventually it dawned on me, this is what the season is: it's the time when rooks build. It might still be on the chilly side, rook-building time, it might be too late for snow and too early for swallows, but it has its merits. Go out and find a rookery right now and I guarantee you'll come away cheerful. One of our five cuckoos is missing A slightly worrying update on the five cuckoos coming back from Central Africa to Norfolk, the birds fitted last summer with satellite transmitters by the British Trust for Ornithology, whose 4,000-mile journey to their wintering grounds in the Congo many people have followed with fascination. Nothing has been heard of cuckoo Clement for three weeks: his last signal was picked up from Cameroon in February 22. In the meantime, the other four birds, Martin, Lyster, Kasper and Chris, have shot past Clement on a north-west axis on their journey back to Britain: Martin is in the Ivory Coast and the other three are currently in Ghana. Although there have been longer periods when some of the transmitters have been silent, the BTO is beginning to be "concerned" for Clement. Fingers crossed. Twitter:@mjpmcmarthy