Seven wonders of nature to spot around London in April.
You know the problem with seasonal nature guides? They're usually packed with extremely challenging plants and animals. We'd all like to glimpse a hawk-nosed chiselmoth, or Shrewbert's lesser-spotted bumbat, or the ring-nosed cackwort that only grows in volcanic soil... but that's never going to happen, is it?
Instead, we've focussed on seven wonders of London's natural world that should be pretty easy to spot. Most can be tracked down in central London if only you keep your eyes open. (The celandines above are a free bonus, as our gift to you.)
Oh, and scroll to the bottom for a guide to wildlife-themed events in April.
Horse chestnut buds
The horse chestnut is a magnificent tree at any time of year, with its drooping leaves, candle-like flowers and shiny conkers. But catch it in the early spring and you'll witness something that looks positively alien*. From late March into April, the huge, sticky buds begin to open. The tight package unfolds into something fantastical as both leaves and flower stretch into space.
Horse-chestnuts are pretty common in the suburbs, in parks, gardens, village greens and sometimes as street trees. There aren't many in central London outside the Royal Parks.
*Which, incidentally, is true, if we use "alien" in the sense of "not from round 'ere". The tree originates from the Balkans and was not planted in Britain until Shakespeare's time. Jokes about William the Conker-er are doubly crap, being both predictable and anachronistic.
You can't miss, or mistake, these absolute beauts. Their yellow-green wings are as sure a sign of spring as an Oscars controversy, and every bit as diverting. The brimstone is like a butterfly in high-vis. If you see a chartreuse blur out the corner of your eye, either you've glimpsed a brimstone or somebody just hurled a highlighter pen at you.
You can even tell the sexes apart from their luminous vest: males are lemon yellow while females have a more greenish hue, with small orange spots (like the one pictured above). Brimstones are around for most of the year, but are particularly noticeable in early spring, when few rivals are on the wing.
It's a funny old thing, blackthorn. During the winter months it's a tangled spiky mess that looks about as inviting as a rusty bed of nails. But twice a year it is one of Britain's prettiest trees. The first is in April when this shrub-tree bursts with white blossom that's so dense, it can look like snow cover. We wouldn't advise attempting to gather a snowball, though — those spikes are renowned for causing infections. Look out for the tree again in late summer when the beautiful blue sloe berries pop out. You can pick them and make sloe gin.
You've surely forgotten most things about your primary school classroom, but this won't be one of them. Watching frogspawn turn into tadpoles turn into froglets — and that dank smell of pondweed — are as synonymous with Year Two as grazed knees and times tables.
Chances are your froggy lessons began in March when the eggs are everywhere. By April, they've metamorphosed into tadpoles. These animated punctuation marks spawn in untold numbers in most healthy streams and ponds (including those in gardens with permeable borders — it's surprising how frogs can get around).
Not so much one to spot as one to listen out for. If, like most people, you're utterly bewildered by birdsong and can only, just about, recognise the sound of a chicken, then the great tit is the level-up you need. Its cry is both very common and very distinctive. Listen out for two notes, repeated over and over, which to some people sounds like "tee-cher, tee-cher". Honestly, you won't find a garden or hedgerow where the cry isn't sounding. You can clock this bird all year round, but it's at its most vocal in April (when thin leaf cover also makes it easier to spot).
April is also a great month to catch the dawn chorus, with sunrise still relatively late and many species of bird in their most raucous spirits.
We've all been up Primrose Hill, but did you ever spot actual primroses there? Probably not. The distinctive flowers need damp, shady conditions, which the park no longer has in abundance. The best place to look is not on hills, but in the shade of trees and hedges along low-lying ground. The ones pictured above, for example, were photographed in a suburban cutting round the back of a Tesco. Primroses bloom as early as February and as late as May, with April about the best time to see them. The flowers come in many colours and varieties, but the pale yellow shown above is most common in the wild. The meaty leaves, like savoy cabbage, are a giveaway identifier.
And finally, a more challenging spot for those who want to see something a little less common-or-garden. To see a warbler, you're best off heading to one of London's wetland environments — the London Wetland Centre in Barnes is the most famous, but places like Woodberry Wetlands near Stoke Newington and Walthamstow Marshes are also good options.
Most warblers are migratory and return to the UK around April time. Reed warblers, sedge warblers and willow warblers can all be found clinging to reeds and twigs in London's wetlands, though you have to have some patience and will almost certainly need to use binoculars. It's easy enough to hear their distinctive calls, though — have a listen online before heading out, so you know what to eargaze for.
Chiffchaffs are another kind of warbler, and perhaps the easiest to spot, thanks to their green colouration (though the willow warbler is similar) and the call that got them their name. They also hang out in woods as well as wetlands and live in the UK all year round, so you're more likely to bag one closer to home. The RSPB has an excellent online guide to the many flavours of warbler.
April 2022 wildlife events in London
London Wetland Centre has a 5am dawn chorus experience (23 April) for true early birds. The kids can enjoy an Easter duck trail (2-24 April) at more amicable hours. And there's a birdsong identification walk on 26-28 April. Budding wildlife photographers can take a six-hour course on 29 April.
Several Royal Parks are putting on Easter holiday wildlife activities, branded as Nature Roadshows. Look out for them in Bushy, Richmond and Regent's Parks as well as Kensington Gardens throughout the Easter holidays.
Epping Forest is the location for one of Michael Holland's two-hour botanical rambles on 23 April.
Barnes Common has a bat walk on the evening of 28 April.