Tales of the Emperor

July in Bentley Wood belongs to the Purple Emperor. Hundreds of visitors from all over the country come to pay court and he - because it is the male that they see - does not disappoint them.

This handsome creature plays to his audience and is probably the only insect to interact so fully with man. Certainly, a number of human activities appear to attract the males down from their master oaks in different parts of the wood. For several years the Bentley Wood authorities ran a Purple Emperor wardening scheme and, as a member, I was privileged to meet many interesting people and see many wonderful displays by this majestic butterfly.

Cars have a special attraction. On many occasions I have seen Purple Emperors float down into the east car park and land on the tyres or windscreen wipers of vehicles. Rubber seems to be the source of interest here and the thick yellow tongue comes out to probe the favoured substance. But I have also seen one sit on the bonnet of a car with its tongue out, clearly enjoying the taste. Enquiries of the owner as to what he cleaned his car with elicited the information that he had driven over from Essex, where he lived by the sea. So salt is also an attraction.

Other episodes with cars include one occasion when a male flew in through a partly open window and flew around inside the vehicle before settling happily on the back seat - much to the delight of the lady driver who announced she would now be closing her windows and setting off for home! On another occasion, an Emperor entered a car while the owner was enjoying a lunchtime snack and settled on his salmon sandwich.

Very often also Emperors will sit on the surface of the car park probing with their tongues into the grit and occasionally they will land at puddles and spend some time drinking. Dog and fox droppings also appear attractive on some occasions, but are ignored on others. Indeed, it became a standing joke amongst the photographers that no ever got a shot of an Emperor on green foliage - although I was fortunate on one very damp day with no visitors around to be wardened when I took a walk along a nearby path and found a fresh male sitting on bracken in the drizzle with one wing, and sometimes both, showing a beautiful shade of bluish purple in the absence of direct sunlight. Unfortunately the light was so poor that shutter speed and depth of field presented problems and several potentially stunning photos were failures.

Other close interactions with butterfly watchers have included, on three occasions that I have witnessed, the butterfly descending from the trees on a hot day and landing on the back of a watcher wearing a blue or purple shirt. Out would come the big yellow tongue to suck perspiration through the material. This would continue for some ten minutes or more, while the only person not to get a photograph and not allowed to move could feel the tongue moving around his back. Camera bags have also been explored in the same way. Through all this, the butterfly seems completely unfazed by the close attentions of perhaps a dozen or more humans crowding around to get the perfect photographs. And salt again appears to be a powerful attraction.

Some of the visitors have their own theories about what will attract the Emperor. This is why the top of the car park notice board is a mass of decaying banana skins and other fruit. But I have never seen the Emperors pay any attention to this display, except on one occasion when someone added a piece of cooked bacon to the banquet. This very quickly attracted the attention of a male which descended and sampled the new offering. Salt again appeared to be the key. But some Emperors seem to have a liking for sweet things, as an enthusiast demonstrated one July day. He made his way through the wood with a jar of molasses, depositing a spoonful or two at selected points and very soon had a trail of Purple Emperors happily supping their treat. When I came upon him again later, he had molasses over a forefinger and a seemingly intoxicated Emperor hanging upside down sampling it through the impressive thick yellow tongue. Another enthusiast had his own theory about what would attract them down as I saw him remove a carrier bag from his car boot and empty a heap of still-steaming horse manure onto the grass at the edge of the car park. ' This should do the trick' he said, 'pony dung - gathered it fresh in the New Forest this morning on my way here'. I have seen Green Veined Whites and Small Coppers probing such material when dried out, but the Emperors were not tempted on that occasion.

The dull, grey morning of 28th July 2002 saw a rather special attempt to attract Purple Emperors down to the car park. BBC naturalist Chris Packham, accompanied by butterfly expert and author Dr Michael Salmon (who was also Wiltshire's bug recorder) and that excellent wildlife cameraman Graham Hatherley, arrived to film the Emperor for a TV piece about butterfly collecting. Despite having been advised that activity would be at its peak some two weeks earlier, the team were prevented by Chris Packham's commitments from an earlier visit. Michael Salmon, who has studied and written about the lives and activities of the great lepidopterists of the past, brought along their recommended equipment for attracting and catching the butterflies, and set it all out in the car park. This ranged from an antique butterfly net to a large white sheet on the ground, mirrors to reflect sunlight into the trees, and fruit, salmon, horse dung and bottles of urine - the latter provoking the following exchange: 'what do you think of my sample - you are an ex-medical man, Mike'? 'It tells me you have a very good renal function, Chris'. Sadly, all this enterprise brought no happy conclusion. After nearly four hours, during which Graham Hatherley picked up some nice general butterfly shots, the only real excitement came when he focussed briefly on the characteristic colours of an Emperor high in an oak tree. Graham tracked it as it flew off behind some bushes, and a bit of later editing and cutting apparently showed it pursued and caught by Michael Salmon, who then opened his net to reveal.......a Ringlet! Nevertheless, the programme made interesting viewing when it was shown early in 2003.

Until a couple of years ago, my wife had never had a close, binocular-free, sighting of a Purple Emperor. But, out with me on a spell of wardening duty in 2003, when nothing much was happening, she wandered off for a walk on her own. Five minutes later she was back to say that an Emperor had come down from the trees, circled around her several times and then settled on the ground right by her feet. And there it stayed while she and several other people crowded round taking all the photographs they required. Truly a most obliging and interesting species, and surely the only British butterfly to use man as a food source.

John Notman

Salisbury and District Natural History Society and Friends of Bentley Wood