Have you discovered the magic of Merlin?

The world can be divided into two types of people — those who have already downloaded the free Merlin Bird ID app, and those whose lives have yet to be enriched by doing so.

Dubbed “Shazam for birds”, being able to hold your phone up and within seconds see names and photographs identifying all the birds singing around you has unlocked the secrets of the natural world for millions, revolutionising birdwatching (or should I say bird listening?) as a hobby.

I’ve been obsessed with birds since I was a small child. I have bookshelves groaning with field guides and more than 100 Emma Bridgewater bird mugs. I rarely leave my house near Epping Forest without a pair of binoculars in hand. But in recent years, I have observed something very exciting. Birdwatchers in Britain are getting much younger.

In fact, almost 750,000 people aged 16 to 29 now watch birds regularly, an increase of more than 1,000 per cent since 2018 according to research published by the Royal Society for the Protection of Birds. The increase among millennials, now 30 to 45 years old, was 216 per cent.

I have always advocated birding as a great (and low-cost) hobby. But its recent renaissance has coincided with the arrival of Merlin’s game-changing educational technology, which offers a portal to the wonder of the everyday.

Owned and developed by the Cornell Lab of Ornithology, Merlin has been downloaded 42mn times since its creation in 2014. There have been 12mn downloads so far this year alone. The free non-profit citizen science tool combines artificial intelligence with reams of data collected via eBird, Cornell’s free bird-logging app. Its sound recognition technology can identify a mind-boggling 11,000 species worldwide (you may know this if you tried it out on holiday).

When I asked FT readers on LinkedIn, many admitted they were addicted and used the app daily. Children adore it. Many parents prefer them to look for birds in their local neighbourhood rather than Pokémon (the Birdex app offers a more gamified experience). Adults are also competitive, and many like to WhatsApp family members with screenshots if they add a new bird to their “life list”.

While Merlin has intensified my birdwatching experience, it has ruined my hopes of beating my personal best time on a 5km jog. I’ll be puffing along through the forest and suddenly have to stop because I’ve heard what sounds like a new bird and need to know what it is.

Last week, I turned a corner and saw a 20-something couple excitedly holding a phone in the air. “What have you Merlined?” I asked (yes, Merlin is now a verb). “It’s a hobby!” they replied. We stood there, craning our necks, and sure enough the red-legged falcon sailed over our heads — the first time I’ve seen one, and an experience I’ll never forget.

While Merlin is not infallible, I have used it to train myself to recognise the calls of dozens more birds, and enjoy getting confirmation that I’ve guessed correctly. However, it would be very useful if it could also identify grey squirrels as their strange alarm calls sound rather bird-like, catching many people out.

Hearing birds is a first step. Knowing where to look for them is next. You don’t even need to have a pair of binoculars, although the £400 I spent on my Nikon Monarchs is one of the best investments I’ve ever made in my mental health.

Before too long, your Merlin obsession spreads to trying to ID what trees and plants particular birds enjoy feeding on (I use the free PlantNet app to help with this). If Merlin tells you there is a goldcrest or firecrest nearby but you can’t see where it’s hiding, look for a holly bush. Want to see jays at this time of year? Lurk near an oak tree and watch them caching acorns. Spot a clump of teasel on your next winter walk? Keep your eyes peeled for goldfinches.

Whether it’s thanks to binoculars or an app, becoming more aware of our feathered friends means we are more invested in their conservation. More than half of UK songbirds are either threatened or in decline. Several readers told me they’ve adapted their garden planting to attract more insects, and thus birds. Lots have been leaving out water in the hot weather too.

A recent episode of Clarkson’s Farm (which many cite as their introduction to Merlin) featured the campaigner Hannah Bourne-Taylor, whose songbird recognition skills are officially faster than the app. She convinced Jeremy Clarkson to delay mowing his grass for silage to save the ground-nesting skylarks. I have never liked him more.

All the data that eager Merlin and eBird users feed back to Cornell helps them track migrant bird populations. This autumn and winter, I’m looking forward to seeing skeins of geese flying south for the colder months and the arrival of winter thrushes like redwing and fieldfares — not to mention spectacular murmurations of starlings.

Of course, I will log these on my Merlin life list. But I’ll end with some sage advice from one FT reader: “Don’t forget to put the phone down every once in a while and just listen.”

Claer Barrett is the FT’s consumer editor; [email protected] Instagram @ClaerB