Monthly Archives: August 2014

An Audience with the Emperor

As Tom mentioned in his previous post, we recently had a very regal visitor to the Visitor Centre. I had been told by one of our Rangers that a Purple Emperor butterfly had been seen around the Centre, and that this wasn’t uncommon. As I had always wanted to see this species, I was thrown into a state of high alert and made it my mission to track one down. Tom and I even placed ‘decoy Emperors’, cut out of paper, around the place in the hope of luring one in. With no success.

Then, one tea break, I wandered into the mess room and was told by our Caretaker, John, that there was a ‘big black butterfly’ in the Education Barn. Pausing only to mop up my spilled coffee and grab a camera, I rushed over and there, as reported, was a big, black butterfly sitting on the glass of the Barn entrance. I clicked off a few photos, but really I wanted a shot of it somewhere a little more natural. Aided by Office Administrator Tracy and an old plum stone, his majesty was coaxed off the window and on to Tracy’s hand, where he posed for several more photos. He was then carried reverently outside and placed on an oak leaf.

Tracy lends a hand

Tracy lends a hand

Unperturbed by all this irreverent treatment, he continued to pose for several minutes, whilst members of staff and visitors filed past to pay their respects.

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So why all the fuss? I’m not alone in being captivated by this particular butterfly; whole books and websites have been devoted to the Purple Emperor. It is neither the biggest nor the rarest native butterfly but it has a kind of mystique about it. Some of this is due to its elusive habits; the adults frequent the highest branches of, usually, oak trees, only coming down to the ground to drink or suck minerals from, of all things, animal droppings. There have been stories of particular ‘master’ trees where the males congregate in large numbers, though this seems to be a myth. And then there is the colour.

Both sexes appear similar from a distance; a dark brown upper surface to the wings relieved by white flashes. But when the light catches the male at the right angle, the reason for the common name becomes apparent; a glorious iridescent sheen unlike the colouring of any other native species.

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I was lucky enough to see Emperors twice more over the summer, but nothing can compare with that special, first close encounter.

Steve Alton

Conservation Officer

Jacobaea of all trades

While people back at the Forest Centre have been enjoying Purple Emperors (not that I’m jealous in the slightest!), myself, Ashley and Katy (a work experience student with us for 4 weeks) have been controlling the spread of Ragwort over the Forest.

As things stand, we have visited every car park on the Forest and tried to remove as many plants as we can from the roadside. There may be stands of Ragwort on rides which we have not got to yet but hopefully we will in due course.

Most of the Ragwort we are pulling up is Common Ragwort, which can grow to about a metre and has yellow flowers. Common Ragwort (Jacobaea vulgaris) has the potential to spread over disturbed or poached soil and can become dominant. It is not a plant that has been introduced the British Isles and Ragwort and Groundsels are members of the Daisy family.

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Common ragwort

Common Ragwort contains toxins (pyrrolizidine alkaloids), which, if ingested in large enough quantities (it varies from animal to animal), can damage and, in some cases, fatally damage an animal’s liver.

Ragworts are an important food source for insects and for some species, most famously the Cinnabar Moth (Tyria jacobaeae), it is their main food plant. Cinnabar Moth caterpillars are black and yellow striped with little hairs and touching them can cause a rash. The caterpillars store the toxins ingested from the Ragwort in their bodies.

Because of the Ragwort’s close association with insects such as this we are leaving some Ragwort for them.

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Cinnabar moth caterpillars

It is worth knowing what is not Ragwort, as there are plants that we have left that do look similar.

The first one, which looks most similar in my opinion, is Perforate St. Johns Wort (Hypericum perforatum). This is a fairly common plant on the Forest and can look very similar to Ragwort but the stamens on the flower protrude a lot further and only have 5 petals, whereas Ragworts have many more!

TomHypericum

Perforate St John’s-wort

Also similar is Common Fleabane (Pulicaria dysenterica), which just to be terribly unscientific, looks like little sunflowers on stalks. Common Fleabane also has a lighter green stem and leaves than Ragworts.

TomFleabane

Fleabane

Common Groundsel, which is also in the Daisy family, has deeply serrated and hairy leaves. This is possibly the most Ragwort-like looking plant of the lot and can also be a food plant of the Cinnabar Moth. I haven’t knowingly found any on the Forest yet but if I do I’ll take a photo of it!

Another plant to that looks similar is this, Goldenrod! This grows about the same height as Ragwort but has pointed leaves and narrow, drooping flower heads.

TomGoldenrod

Canadian goldenrod

Finally, we have something that can look surprisingly like ragwort from a distance: dead Bracken!

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That’s all the yellow flowering plants I can cope with for now!

Should have some good insects for the blog!

Your friendly Countryside Worker,

Tom.