'A Field Guide to (some of) The Peoples of the British Isles' by Chelsea Renton (Oneworld Publications)

Chelsea Renton watches people. Then, because she is an artist, she also draws and paints them, for her own amusement and, luckily, for ours. Since 2017, she has been entertaining readers of The Oldie with her cartoons, and – in time for Christmas – has published this full-colour, illustrated Field Guide, stylistically organised in the manner of the best field guides to birds of the British Isles. Insofar as birds are concerned, a guide should be 'easy-to-use, wholly accurate, succinct, up-to-date and well illustrated', among other attributes, and Renton nails them all.

She was, she writes in an email interview, 'wandering along the machair of Tiree with a bird book, when I stopped at the edge of a beach to look at people. There was a large bunch of summer incomers (called "swallows") having a noisy barbeque and drinking wine while their children shivered in the surf. Perhaps that's how the idea for this book formed'.

The Guide, as with all handy bird books, arranges its subjects sensibly, enabling easy recognition. For example, under the heading of 'Seasonal' one finds the 'Surfer: sex – male; distribution – coastal; habitat – camper vans'. Perhaps because Renton's cartoons often appear in The Oldie, this surfer is paunchy, middle aged and heading for a heart attack. Renton agrees that observations are often about surface, but reveal something beneath. 'In many ways cartooning gets closer to the truth than standard portraiture, which is always a compromise between what I see and how the sitter perceives themselves. For a cartoon to work it has to tap into the essence of someone and exaggerate key physical features, and it's not always particularly favourable.'

This is certainly true of the female 'DFL (Down from London)'. Observing the DFL 'in the field', her arrogance knows no bounds, as she insults or patronises the locals whose sheep block the smooth passage of her large 4X4. She comes under the heading of 'Pest', which also includes property developer, celebrity and traffic warden. A helpful 'identification chart' provides 'profile' and 'species', plus useful sketches of 'tracks' made by their various footwear. One can also look up ladies who lunch, landed gentry, builder, therapist, local councillor or parent, among many 'birds of plumage', also artist (amateur) and foodie.

While Chelsea Renton has always doodled what she calls 'silly sketches' of people, she is mainly known as a portrait painter. 'My best portraits are when I know the sitter is happy for me to do them as I see them, and not as they wish to be seen. I need to talk to the person first, and see how they hold themselves. You need to know someone to capture some of the soul.'

In drawing cartoons, Renton's technique is to work with a dip pen, sometimes homemade from bamboo, and she uses a watercolour wash at the end. The colourful illustrations on every page contain clever details that bear close examination. Normally her work is quite loose, but, she says, 'for the Field Guide I wanted the drawings to be as precise as a bird book'. Under 'Juveniles', for instance, one small, sad little girl – a trunk and hockey stick beside her – depicts the woe of being sent to a distant boarding school; the 'identification chart' for juvenile variations in plumage captures everything from piercings to incipient beards.

Renton classifies herself as a 'jobbing artist' and relishes the challenges of different types of commissions. She also is a landscape painter – including large abstract works – which serves as a complete change from working on small-scale illustrations. She also enjoys making portraits in plaster or clay, and has been an artist in residence at Glyndebourne where she produced caricatured fired clay heads of the cast and staff.

Her cartoons for The Oldie are very much in the nature of caricatures, and this suits the essence of the monthly magazine, which states that it is a 'light-hearted alternative to a press obsessed with youth and celebrity'. It is not age specific, covering theatre, music, wine, media, politics, style and food. What's not to like? With Harry Mount as editor from 2017, its circulation has grown and it continues to fulfil the promise that it is 'for anyone who has a sense of humour and likes cartoons'.

Although Chelsea Renton says about herself that she is mercurial and impulsive, her distinctive drawings – specific and spot on – show her skills as a careful and very thoughtful observer of people and of human nature. 'This is a light-hearted book and I have consciously steered away from both sad and difficult personalities. I don't want to poke fun at them, in the same way I find it hard to poke fun at a doctor or teacher. I've focused on types according to behaviour or jobs as these cut across ethnicity. Lots of the characters have distribution maps showing where they appear in Britain, often quite accurate and sometimes the result of wild speculation. I am happy to admit that this is a very silly book.'

There must be a great many people who would appreciate a bit of silliness and A Field Guide is the perfect prescription for dark winter days and an antidote to despondency. You may even find yourself – or someone you know well – included in it.