Not perhaps the best day to be wild, but after a long dry spell much of our wildlife will be welcoming the rain. Birds like song thrush and blackbird need worms to rear their young. The snails will welcome some rain as it will deflect the thrush from eating them and enable them to get out and eat my vegetable plants!
However it did not rain all day and in a brief sunny interlude I found a blue butterfly in my mini-meadow and not just any blue, but a male silver-studded blue.
To record an odd individual might not seem a great surprise, but I have seen them every year and sometimes several individuals of both sexes. This is a heathland species, renowned for having colonies that are very localised. In fact research has shown that most travel no more than 50m from where they hatch and many only up to 20m. Their flight is quite weak and usually low to the ground, in short they don’t get out much!
When I see them in the garden they are in the mini-meadow, a tiny grassland about 4m x 5m, otherwise the garden has a small lawn and flower borders with a small vegetable patch, no heath at all. What is more I live in the midst of ordinary suburban gardens, across two roads there is the New Forest, but even then it is short turf and conifer plantation. The nearest silver-studded blue colony is relatively close at 750m away, but it seems that this is something like 15 times as far as even an fairly intrepid silver-studded blue would go in a lifetime. To cover this distance would also involve not crossing open heath, but a large conifer plantation, two roads with hedges and a further line of trees. Even stranger the butterflies I see are, like today’s, not well travelled, worn, veterans but freshly emerged and pristine.
Silver-studded blue have remarkable lifestyles, their association with ants is only matched by the large blue. The newly hatched larvae are taken into the nests of one of two species of black ant and only venture out at night to feed on a variety of plants, but on heaths, usually heather or gorse seedlings. The caterpillars secrete a sweet substance beloved by ants, in fact it seems they suffer when it is not removed by ants.
The mystery of why I see them regularly in my garden remains, maybe they do breed in my meadow, but if so they are feeding on bird’s foot trefoil, something the heathland variety does not usually do, although they do so in limestone areas such as on the Great Ormes Head. It would also need there to be the right ants present, something I cannot confirm and it would be in a very atypical habitat, so seems very unlikely.
If anyone can shed any light on this mystery I would be delighted to hear, I am at a loss to explain why they appear so often so far from their nearest colony.