Nature Studies by Michael McCarthy: The best discoveries canbe entirely accidental

It seems to me a curious part of the human psyche that we more deeply enjoy special things seen casually and accidentally, than those which have been expressly sought out. Certainly this applies to the natural world. So much of the wildlife which once surrounded us has been lost that to set eyes on many distinctive species we are now obliged to make expeditions. We go birding, or botanising or butterflying: you're unlikely to see a wood warbler, or a military orchid, or a swallowtail, without going in search of them. Often, of course, the results are very satisfying, and long to be remembered, and worth the journey.

Yet to come across such fascinating parts of nature quite by chance, while going about our daily business as it were, is somehow an intenser pleasure. This was how people used to encounter the natural world in all its richness. Take Shakespeare: he mentions by name more than 50 bird species and more than 100 types of plants and wildflowers, sometimes in exquisite conjunction

... daffodils

That come before the swallow dares...

but there is no evidence that young William was ever secretary of the Warwickshire Wildflower Society, or chairman of the Blackfriars Bird Club. His breadth of knowledge of nature is greater than that of any other English classic writer but it came entirely from casual, everyday encounters which are largely unavailable to us now; perhaps that's why when we do experience them, the pleasure is all the greater, as I found last month on holiday with my family in France.

We spent part of it in Brittany, in a small fishing port called Camaret. It was charming, in its setting underneath a heather-covered headland, in its old fortified harbour, its backstreet art galleries and not least in its collection of seafood restaurants facing the water. That's what people go there for, I guess. But I liked it particularly for the bits of less-common nature dotted about the place.

The harbour walls, for example, were covered in samphire, a fleshy seaside plant which has once again become fashionable eating in recent years (and was well known to Shakespeare); the harbour waters themselves, when they crept up with the tide, were full of large grey mullet, squat silver torpedoes; and on the rocks underneath the lighthouse were creatures which caused my wife to exclaim: what are those lovely birds? They were turnstones, waders in their summer plumage of terracotta and chocolate, scarcely given a second glance on birding trips but here a stunning attraction.

It got even better on a walk over the headland, whose bell heather and ling were in their full purple glory. The point of the walk was the champagne air and the stupendous sea view over the roadstead of Brest, but along the way were accidental bonuses. First were grayling butterflies, seaside heathland specialists in their subtle colour scheme of grey, yellow and orange; they perch on the path with their wings closed and suddenly they're invisible.

Then there was a sharp call in the air, pyaaa, pyaaa! which, even before my brain had finished telling me that's not a seagull delivered the inspiring sight of three choughs, Europe's rarest and most charismatic crows – also well known to Will S. – tumbling through the air with the light catching their splendid, decurved scarlet beaks.

Finally, near the end of a walk which had been enlivened all the way by clifftop wildflowers, was a wild plant of startling beauty, a flower of a crimson so deep it seemed to be glowing. It was bloody cranesbill, Geranium sanguineum, an uncommon bloom which botanists will travel to see, yet here it was growing by the side of the path in casual profusion.

None of this wildlife-fest was sought out; it was just an accidental part of a seaside holiday. But it felt all the richer for that.

Floral glory on the French roadsides

Another casual encounter with nature in France which is worth having is with the flowers of the roadside verges: they seem far showier than their equivalents in England. Right now one which is in full bloom is common yellow toadflax, the wild equivalent of the snapdragon: pale yellow with a flaming orange lower lip.

It congregates in startlingly bright masses, sometimes mixed with the deep purple of tufted vetch and the browny-pink of hemp agrimony, giving the country roads very much a decorated feel.

Once you get into the villages, of course, the flower decorationis deliberate.

Peace at last for the Devil's Punchbowl

On the way to France, heading down the A3 to Portsmouth, the last bottleneck still remained: the traffic lights at Hindhead, which have been producing 10-mile tailbacks for decades. On our return, the £370m Hindhead tunnel had at long last been opened and the A3 is now a fast dual carriageway from south-west London all the way to Portsmouth.

The tunnel is a triumph: it not only relieves Hindhead village of its vehicular burden, it takes all traffic away from the Devil's Punchbowl, one of the most majestic landscape features of southern England. As we could see at once from the car, the tunnel landscaping itself has been beautifully done. Congratulations to the Highways Agency and the chief engineer on the project, Paul Arnold.

m.mccarthy@independent.co.uk; twitter.com/mjpmccarthy