The Magpie's Hoard

In Praise of Thistles

Sheffield may have missed out on the thunderstorms that drenched much of eastern England yesterday, but the weather today was a bit cooler and less humid than it's been for a while.

This morning I caught a bus out to Lodge Moor and walked along the 'conduit path' to Redmires Reservoirs. I particularly wanted to take some photos of butterflies as there seem to be so many about right now.

Sure enough, I saw dozens of them: peacocks, small tortoiseshells, commas, gatekeepers, small skippers, red admirals and painted ladies.

Now that the brambles have finished flowering, the plant that attracts by far the most butterflies is the creeping thistle (Cirsium arvense).

It's not only a magnet for butterflies; I spotted hoverflies, wasps, bumblebees and beetles all feasting on its pretty, lilac-pink blooms.

This emphasises a point I made in an earlier post: that butterflies find indigenous plants are far more attractive than introduced ones. The trouble is that I don't imagine that many gardeners could be persuaded to cultivate creeping thistle, just for the benefit of wildlife!

[Note to self: with hindsight, shorts and sandals are not the best clothing to wear when photographing butterflies on thistles.]

Riding the Heatwave

As the UK's heatwave continues, much of the countryside is looking parched and brown. Many areas of heathland are tinder dry and extremely vulnerable to fire, as the recent blaze at Thursley Common demonstrated all too clearly.

Although fire is often used as a management tool in heathland, uncontrolled summer fires can be devastating for reptiles and  ground-dwelling invertebrates. The problem is compounded by the fact that most of Britain's lowland heaths are now split into small isolated fragments; once a site has lost a particular species, it is unlikely to be re-colonised.

On the positive side, the heatwave is bringing some exotic visitors from southern climes. For instance, unprecedented numbers of migrant lesser emperor dragonflies (Anax parthenope) are being reported from as far north as Cumbria and Tyneside.

This morning I noticed a few painted ladies (Cynthia cardui). When the weather conditions are right, vast numbers of these butterflies disperse northwards from their breeding grounds in North Africa. From time to time the UK receives a major influx, the most memorable being in 1980 when they seemed to be everywhere.

Of course not everyone welcomes migrants from overseas. The Daily Mail warns of "the rise of the Euro-wasp" which, if the article is to be believed, is hell-bent on hospitalising the good citizens of Middle England. However, as the Guardian reported a couple of years ago, we should check an immigrant's ID before we fly into a panic!

Abbeydale Industrial Hamlet

This morning I visited Abbeydale Industrial Hamlet for the first time in nearly 20 years.

Peter, one of my former students, kindly offered to show me round. He works at the Hamlet and is involved in the restoration of the dam that feeds the water-powered machinery.

One of the aims of the restoration is to improve the dam as a wildlife habitat, whilst meeting the needs of the industrial museum and the local anglers. To help achieve this, a lot of marginal vegetation has been introduced: mostly Glyceria maxima and Iris pseudacorus.

From an ecological point of view, the restoration certainly seems to be working. The eastern bank of the dam was teeming with insects. Peter pointed out various species of hoverflies (Syrphidae) that were feeding on flowers of umbellifers. I'm still very much a novice when it comes to entomology, but I'm gradually learning to recognise some of the more distinctive species.

I managed to get a few decent shots of blue-tailed damselflies (Ishnura elegans) resting on the leaves of Glyceria. Common blue damselflies (Enallagma cyathigerum) were also abundant, but far too fidgety and flighty to photograph.