Bird watching used to have a stuffy reputation, which is probably why there were just 5,000 members of the RSPB when I joined at the age of eleven.

It wasn't so much a hobby as a science. You didn't really bird watch, you studied ornithology. And when you went on a walk (or "a field trip" as it was known), at frequent intervals you pulled out a notebook to keep records of observations, making rough sketches of any unfamiliar birds and annotating them with scribbles like "green scapulars" and "dark tarsus".

The Bible for beginners was the Collins Guide to Bird Watching by Richard Fitter, and in it he advised that you should always make notes before consulting any book. Writing down "a little yellow and brown bird with some white on it somewhere" wasn't very helpful, he said, and suggested a list of 12 points to note before you checked the species when you got home.

Times have changed. There are now over a million members of the RSPB and for many years if you visited one of its 200 bird reserves you would almost certainly find people sitting in observation hides with a bird book, leafing through the pages and muttering "wood sandpiper".

Now, all the information you could possibly need to positively identify a bird – plumage, song, flight, feeding habits – fits easily onto the new generation of mobile phones and MP3 players.

The UK's leaders in the digital, hi-tech world of bird watching are Sheffield-based BirdGuides Ltd, whose flagship mobile product – British Birds Video Guide – allows you to load on to an iPhone or iPod Touch MP3 player an impressive 16 hours of sound and video covering the 270 species of birds regularly encountered in Britain. The company has also just produced a downloadable guide to British Butterflies showing sketches and photos of the 61 species found in the UK. Further guides are planned.

I loaded them on to my iPhone and took them for
a test drive. My first destination was the fringe
of some woodland on Rombalds Moor, between Airedale and Wharfedale, where I expected to find two oft-confused species side-by-side.

Meadow Pipits and Tree Pipits are easy to tell apart if you hear them singing or calling regularly, but identifying them by sight is more problematic.

With a bird in view, my phone soon told me I was looking at a Tree Pipit. The close-up video showed it had fine streaks on its flanks and for confirmation I compared it with video footage of the Meadow Pipit. So much easier than colour plates in a bird book.

Next, I visited Rodley Nature Reserve on the River Aire between Kirkstall and Horsforth, Leeds, and demonstrated the software for volunteers Peter and Barbara Murphy.

Peter immediately went for a comparison between the easily-confused songs of
the Garden Warbler and Blackcap and was impressed. Barbara looked at video of a Common Whitethroat – one of Rodley's most distinctive species in summer – and thought it would be an excellent way of teaching schoolchildren how to identify the bird.

She said: "The official way of putting a name to a bird you couldn't identify was always to make notes, but I think this method will appeal."

Peter added: "It probably won't grab the old dyed-in-the-wool bird watchers, but younger bird watchers... people who are in their teens or their twenties who seem to live their lives through their mobile phones... will probably love it."

The only negative point they found was that bright sunlight muted the colours.

They were also the perfect people to pass judgment
on the mobile Butterflies guide. They established a butterfly garden at Rodley and are good at identifying the species found there – even uncommon ones like the White-letter Hairstreak.

"For beginners, this would be very helpful," Barbara said.

So would I break the habit of a lifetime and start checking unfamiliar birds and butterflies while I'm seeing them, or continue
to make notes? I'll probably do both. If it's on my phone, the instant identification guides will often be hard
to resist.

n British Birds Video Guide for iPhone and iPod Touch
is available from www. birdguides.com while Butterflies is downloadable from Apple's App Store, via iTunes on Macs and PCs.

n Rodley Nature Reserve is signposted off the A657 in Rodley Town Street, four miles west of Leeds city centre. Opening times: Wednesday, Saturdays and Sundays 10am-4pm.