Monday, 29 June 2015
Blue tailed damselflies (Ischnura elegans) have joined in the summer fun. It may be my imagination but they seem the shyest of the local damselflies, diminutive compared to their cousins. Common red damselflies have an assertive flight, positively bossy in manner . They are on the wing early too and have been quartering their wetland homes for a few weeks now. Azure damselflies are also purposeful, zippy, an effect accentuated by the vivid almost all over blue of the males. The blue tails though tend to be more wary, fluttering into cover if you approach too boldly. The males are a slate grey with the blue spot at the end of their abdomen sometimes seeming to be in flying solo if the rest of the damselfly is obscured amongst the sedges and herbs. The females are even less conspicuous, although if you can sneak up close you’ll often find one flushed with a lilac thorax (the middle part of the body, bearing the wings and legs) or pale chestnut. This little male is giving himself a wipe behind his eyes before setting off on patrol, stretching his left foreleg over his head to wipe any specks from his bulbous eyes. His blue tail spot is not fully coloured yet, but will become more intense with time. Watch out for blue specks floating through the plants around wetlands; each speck is likely to be a male blue tail, even if the rest of him is hard to see.
Friday, 12 June 2015
Thursday, 4 June 2015
Blakemoor Farm’s new field corner ponds are doing nicely. The freshly hatched tadpoles of a couple of weeks ago (see 3rd April) are now plump and assertive. They are also playing statistical games. In one of the ponds all the tadpoles are squirming together in a dense black swarm. In the next door pond they litter the sediment, scattered with a pleasing eye for complete coverage. In a third pond there are none. Statistics are not what inspires many people’s interest in natural history, although I know of mathematicians who have been lured into ecology on the grounds that it is much more challenging. Statistics have their uses though, especially to summarise and test observations. The trouble is when nature plays fast and loose like these tadpoles. In the first pond there are fairly simple quantitative methods that will tell you that tadpoles have a clumped distribution, whilst in the second pond that they are more or less evenly scattered about. The trouble is that the perfectly clear maths makes no sense overall because the tadpoles are doing different things in different ponds, or not turning up at all in the third pond. I doubt that the Large Hadron Collider, turned back on again today to crack even more secrets of fundamental particles, could help unravel the problem of the mathematically inconsistent tadpoles. Tadpole uncertainty may not have the ring of quantum uncertainty or the fame of Schrödinger’s cat as a conundrum but they are a lovely mystery right on our doors step, just over a wall from the dune road.