Natural migration is one of the world's wonders. Consider the many bird species little bigger than babies' fists flying epic journeys, through heat and tempest over desert, forest and ocean for a spring and summer stay in Britain. And then, within the year, undertaking the same distance again, back to their wintering grounds. Just think of the arctic tern, flying from the top of the northern hemisphere to the base of the southern, for the continued perpetuation of the species!
• Willow Warbler
Here in the southwest we have enjoyed a fine start to the season with a visit at Velator pond, Braunton, of a garganey a duck species unusual as being a summer, not winter visitor to this country from Africa. From the same continent warblers seem to have arrived in strength, particularly the common whitethroat. And whimbrel have passed through in number.
Such feats of endurance are staggerng to contemplate. And yet. insects, delicate entities weighing hardly a gram, also make these epic flights. A few butterfly and moth speces annually arrive here in varying quantity.
• Painted Lady Butterfly
Painted lady butterflies are found worldwide, with the exception of South America. Those that arrive here in the UK - and in an average year found sparingly - will have migrated from the desert fringes of north Africa along an eastward spreading line to central Asia. However every decade or so there is a mass invasion into mainland Europe and upwards into the UK. This is brought about by exceptional rainfall in their homelands triggering a bountiful supply of foodplants. In consequence, mass hatches of the insects occur, in turn producing a mass movement away from the natal areas owing to an inexorable sharp decline in vegetation. There was a painted lady 'year' beginning toward the end of May into June 1996, which I well remember - finding them plentiful at Westward Ho! ) At that time a prolonged flypast, from mid-afternoon to dusk, was witnessed over one mid-Devon village by a Fellow of The Royal Entomological Society no less. It is also recorded that 1879 and 1903 were exceptional years.
• Underwings of a Painted Lady Butterfly
The sheer volume of this year's influx would suggest it to be at the very least on a par with these. Millions have wafted across the English Channel and made it far beyond the Scottish border! Travelling distances in excess of a thousand miles to reach us these insects certainly elicit awe.
Having seen one's and two's as early as April I suspected it might be a good year for the species. At Instow on May 30 this notion was certainly vindicated for off the estuary they were breezing in at head height throughout the day. And numerous all along the coastal strips as well as the hinterland. Painted ladies are strong fliers with exceptional stamina and are abroad far longer during daylight hours than other butterfly species - well into the evening. In fact I have seen them still active at 9.00pm. Feeding on thistles, mallows, burdock and nettles there is little fear of their larvae defoliating crop or garden plants. In fact they should be welcomed for their weed control potential.
Compared to other (bright-liveried) members of the Nymphalidae to which it belongs - eg Purple Emperor, Red Admiral and Camberwell Beauty - it is, in my opinion, dull in appearance having a flat base colour of tawny-brown falling short of redemption by black markings and white spots on the forewings.