Butterfly Report 2012

Over the winter and into spring much work was done in the continuing effort to improve the woodland environment for butterflies and other wildlife. In places the dogwood was cut back, opening up areas to encourage more varied woodland plants. Several wych elms, food plant of the white letter hairstreak and popular with comma butterflies, were planted. Hundreds of violets, cowslips, red campion, honeysuckle and other wildflowers that are good for insects have been planted throughout the wood, along with a strawberry tree, which is a late-season nectar source for butterflies and bees with clusters of lily-of-the-valley-like flowers.

Later in the year, 32083 bluebell seeds† were spread in a small number of areas – all things being well these

should flower in 5 years or so.

It seems a distant memory, but early spring was unusually warm and the first butterflies were seen on March 11th, a gloriously sunny day, which brought several male Brimstones out of hibernation. Peacock and Comma followed later in the month, and April 1st, the beginning of the official butterfly recording season, saw the first Orange tip and Speckled Wood. All the talk was of a hot, dry summer, and there was the impending threat of water shortages as a wave of hosepipe bans began creeping towards us county-by-county from the south-east. In the event, things could not have turned out more different, as the South West turned wet and cold and there began “the wettest drought for 100 years”, as the tabloids were later to tell us. The impact on butterfly numbers was severe, to the extent that Green-veined White was the only other species recorded by the end of April.

Despite the less than ideal weather during visits to the wood in April, both Peacock and Orange tip were seen regularly, although many sightings of the latter were of roosting individuals, sitting out the frequent showers on the flower heads of garlic mustard or cow parsley. Maybe because they were not on the wing as much as normal, or because the cold weather delayed emergence of some individuals, the flight period of the orange-tips was unusually long, and they continued to be seen through to the end of May. May also saw the first Large White, and Small White, but the impact of the poor weather on overall butterfly numbers was becoming only too clear, with smaller species in particular suffering locally. Just a single sighting of Holly Blue was made during the month, whilst Brown Argus, Common Blue and Small Copper were not recorded at all. Numbers of these species were also severely down elsewhere on the Weston hills, and across Bath in general, and will probably take time to recover to their normal levels.

A Red Admiral was seen on the final visit in May but it was not until June that the first Large Skipper was seen – a month later than normal, and in numbers well down on recent years. Meadow Brown, on the other hand, appeared on schedule, and by the end of the month the first Ringlet had been seen. A lack of sightings of Marbled White was worrying, being a favourite species, but they turned up a couple of weeks late at the start of July, and all things considered put in a reasonable showing. Small Skipper appeared mid-July, again about 4 weeks later than normal, and, although only a handful of sightings of this species were

made during the month, I was pleased to see and photograph amongst them a pair of the almost identical Essex Skippers. July saw the first second-brood Speckled Wood take to the wing – they continued to be seen

Green-veined White on Dandelion

Marbled White on knapweed

† No, I didn’t count them! 275g of seed, and assuming 1.2g=140 seeds

until late October – and the first Gatekeeper. Remarkably, whilst most species were suffering, Meadow Brown numbers peaked at 245 seen on July 22nd, a figure twice the normal maximum count.

August turned out to be the highlight of the butterfly year, and no doubt the filter of time will ensure it is the memories from that month that remain longest, and not the disappointments of the preceding months. The wildflowers in the Jubilee Diamond came into their own and it was a pleasure to see them alive with bees and butterflies. This wildflower seeding is an experiment we shall repeat. An unusually marked Ringlet was seen in the wood, ab. arete, in which the distinctive wing spots were almost absent. On Sunday 19th, a hot, sunny day during which Weston Gardening Club visited, Peacock numbers reached a notable peak of 101 – as usual, they were particularly attracted to the buddleia – and that same day we had the first confirmed sighting of a Silver-washed Fritillary in the wood, seen by Trevor and John on the buddleia near the crossroads, and still there when I did my survey. Silver-washed alludes to the under wing markings but I find the German name Kaisermantel, or Emperor’s cloak, more redolent of the rich and luxurious appearance of fresh specimens. The one seen in the wood was a slightly worn individual – they first take to the wing in early July – but still an encouraging sighting, as this is a species we hope will become resident when the common dog violets become widespread.

In total, 16 species were seen during August, including several Small Tortoiseshells seen on the last day. Numbers of this species have suffered in recent years so it was pleasing to continue seeing them throughout September. The final species I recorded in the wood this year was Painted Lady. Alastair reported seeing one in August but it was not until September 4th that the species turned up on my weekly survey. Watching them perform circuits in the vicinity of the buddleia near the crossroads, it was nice to be reminded of what powerful and graceful flyers these remarkable butterflies are – indeed research published this year has revealed how, in the course of several generations, they undertake a 9000 mile intercontinental migration from tropical Africa to the Arctic Circle and back, departing south from the UK at an average height of 500m to take advantage of air currents. And they weigh less than 1 gram!

Numbers of several species held up well through September and into October, especially Brimstone, Red Admiral and Speckled Wood, and amazingly I recorded at least one Comma on 16 consecutive weekly visits up to October 24th, undoubtedly reflecting greater abundance within the wood. This last date was a working party day on which Brimstone, Speckled Wood and Peacock were also seen – a nice reward for the hard work put in!

So that was 2012. It will be interesting to see what impact the poor spring and early summer weather will have on butterfly numbers in 2013. Will Common Blue, Brown Argus and Small Copper make reappearances? Will Silver-washed Fritillary be seen again? If you notice anything of interest, please send in details to primrosebutterflies@gmail.com. I have also put together an identification guide if you would like help recognising the different species in the wood, and copies of this will be available in the library box in the spring.

Variation in the wing spots on Ringlets, ranging from normal (left) to ab. arete (right)

Primrose Hill Silver-washed Fritillary (top) and (below) a fresh

specimen from Inwood (nr Bath).

Butterfly ID guide

Simon