Elation, wonder and curiosity – they were three emotions involved in seeing three of Britain's rarest butterflies. Elation was for the swallowtail, our most glamorous insect, finally tracked down in its Norfolk Broads home on Friday after an initial safari proved fruitless. Wonder was for the heath fritillary, a handsome lattice of orange and black now restricted to a handful of sites, but found flying in thousands on Saturday, in a dappled clearing deep in a Kentish wood. And curiosity was for the black hairstreak, a pint-sized creature located on a nature reserve open day in Northamptonshire yesterday – surrounded by photographers.
As the destinations indicate, to see these three species on three successive days involved a lot of travelling – the total mileage was 722 miles, starting in each case from west London. Yet the hours behind the wheel were in each case rewarded with memorable encounters with the natural world.
With the swallowtail, there was no alternative but to trek to the Broads, as this is its remaining home in Britain. Like the Granville fritillary on the Isle of Wight, or the chequered skipper in western Scotland, both of which we have already covered as part of The Independent's Great British Butterfly Hunt, this is a butterfly now restricted to one area, and if you want to catch sight of Papilio machaon you have to make the journey to Norfolk.
It's worth it. When you see it, you are taken aback. You stare, as if you can't quite believe what you're looking at. For in form and colour both, the swallowtail is magnificent. It is Britain's largest butterfly, and its extravagant mix of black and yellow, with two spots of crimson, combined with its long black spiky tails, give it an air of the exotic which make it stand out amid the gentle greenery of our countryside.
We went looking for it at Catfield Fen, a wetland on the edge of Barton Broad and a noted swallowtail site, accompanied by two experienced members of Butterfly Conservation's Norfolk branch, Mandy Gluth and Bernard Watts. They were optimistic we would find it; they were wrong. Although Bernard caught sight of two, I missed them both, and after a morning and half an afternoon scanning the reed beds and sedge beds in unfavourable weather – showers and a strong wind – I remained swallowtailless, with a mounting anxiety that I might have driven 170 miles for nothing.
Mandy and Bernard decided to try a different site: How Hill, a former country estate which is now an environmental education centre, a few miles away, on the river Ant. And here, almost immediately, we were successful – perhaps because the sun had come out – for in a meadow by the riverside, a swallowtail was nectaring on the purple flowers of marsh thistle, and was quickly joined by two more. I was elated, and like several butterfly-watchers already in the meadow, I was agog at the sight: they seem positively outlandish. It's not a scene you can forget.
Yet just as memorable was the spectacle the following day of enormous numbers of one of our least common butterflies, the heath fritillary. This now exists in only a tiny number of places in the West Country, Essex and Kent, but the Kentish colony, in Blean Woods near Canterbury, is a strong one, thanks to the work of the local RSPB warden, Michael Walter, who carefully manages the habitat for the butterfly as well as for birds. On Saturday, Michael took me deep into the woodlands – about two miles down a track – then branched off down a side track into an open glade, and there we suddenly found heath fritillaries flying in thousands, fluttering a foot or so above the vegetation and catching the light in a silence broken only by birdsong. It seemed like the clouds of butterflies people used to talk about, before the natural world was degraded by chemicals.
The third of the weekend's rare species was a small butterfly now restricted to a few colonies in the East Midlands, the black hairstreak. This we found at Glapthorn Cow Pastures, a Northamptonshire nature reserve run by the Wildlife Trust for Bedfordshire, Cambridgeshire, Northamptonshire and Peterborough. Finding it wasn't hard: it was an open day on the reserve and staff were on hand to direct visitors to a patch of brambles, where a single black hairstreak, its wings unfortunately closed as always when at rest, was surrounded by half a dozen enthusiastic butterfly photographers, all pointing tree-trunk-sized long lenses at a butterfly hardly bigger than your thumbnail. But there it was.
These three species, plus another two – red admiral, seen at Catfield Fen, and ringlet, seen at Glapthorn - brought The Independent's own total in the Butterfly Hunt to 35 out of 58. We are well on the way to our aim of seeing all the British species in a single summer. But perhaps this account illustrates that to accomplish it, quite a lot of time, expense and travel is necessary. For anyone struggling to do it, we can recommend a book – Discover Butterflies in Britain by David Newland (illustrated left) published by WildGuides Ltd ( www.wildguides.co.uk). This shows where all the British butterfly species can be seen, with directions on how to get to them and how to move around inside the sites once there. Most of the locations from which we have reported are featured in the book.
The Great British Butterfly Hunt: Species 27-29 (of 58)
In the tenth of our status reports, we describe three rare butterflies which all require a journey to be seen, plus good weather and a certain amount of luck. All are very uncommon but, hopefully, their numbers remain stable for the moment.
27. Swallowtail Papilio machaon
*The great glamourpuss of the British lepidoptera, unmistakeable in its outlandish livery of banana yellow and black, with blue and crimson thrown on for good measure. Apart from – perhaps – the purple emperor, it is the only British butterfly which can match tropical species for striking appearance. Many butterfly enthusiasts make special trips to Norfolk to set eyes on it.
*Larval food plant: Exclusively milk parsley, a wetland plant of the carrot family. Continental swallowtails use a wider range of plants.
*Where seen: Once found throughout the fens, and even down into the Thames Valley, but since its extinction on Wicken Fen in Cambridgeshire in the 1950s it has been confined to the Norfolk Broads, despite attempts to reintroduce it elsewhere.
*Current conservation status: Not enough sites to construct a trend but thought to be stable and doing well on a few Broadland nature reserves.
28. Heath fritillary Melitaea athalia
*This is a very attractive small butterfly which seems black in the middle and orange on the outside. It was known as "the woodman's friend" because as new coppices were cut inside woods (to provide a supply of long thin branches for poles and fencing) it would follow with its breeding from one coppice to another.
*Larval food plant: Common cow-wheat, a plant of coppices and clearings inside woodlands.
*Where seen: At just a few sites, in sheltered heathland valleys on Exmoor and on grassland in Devon and Cornwall, and in Kent, where the butterfly is found in woodland clearings.
*Current conservation status: A terrible long-term decline – 68 per cent since 1984 – but things have picked up in the past five years owing to strenuous conservation measures.
29. Black hairstreak Satyrium pruni
*The hairstreaks are small butterflies related to the blues, fairly inconspicuous and pretty difficult to track down, often spending time in the treetops. Finding and getting a good look at a black hairstreak is regarded as an achievement by many a butterfly watcher.
*Larval food plant: Blackthorn (the spiny shrub that produces sloes).
*Where seen: In woodland glades where there is a plentiful supply of blackthorn, in a very restricted area of the south and east Midlands, especially Northamptonshire.
*Current conservation status: Too elusive and too difficult to count to provide a trend, but thought to be holding its own.