30 Days Wild – Day 17 – Butterflies and More

We have been doing butterfly transects at Blashford Lakes for some years now, I say “We”, what I really mean is that the volunteers have been doing them. I used to do transects myself on previous sites I have managed and thoroughly enjoyed doing them, an opportunity to go out on site for the main purpose of looking for wildlife, something I actually get to do rather rarely! In theory I have always been on the rota to help with the transects at Blashford, but as a stand-in, if someone else is unavailable. Well this week I have been called upon and as it was warm and reasonably sunny this afternoon I headed out.

It was not a classic butterfly day but I did see 26 butterflies of four species. Most notable were the five red admiral, I suspect they are new migrants as the weather is set fair for an arrival of migrants over the next day or so. Locally bred were meadow brown, common blue and speckled wood.

speckled wood

Whilst looking for butterflies it is inevitable that you will see other invertebrates, I saw six species of dragonflies and damselflies, several yellow-and-black longhorn beetle and lots of the larger summer hoverflies, especially Volucella bombylans and Volucella pellucens. 

Vollucella pellucens

Not all of the invertebrates were adult, I found a vapourer caterpillar feeding in the open, something they can afford to do, as they are protected by a dense coat of hairs which most birds will avoid.

vapourer caterpillar

Some things I cannot identify, or at least not accurately, one such is this digger wasp, I am pretty sure it is one of them, but which one?

digger wasp spp.

Some of the invertebrates were not insects at all, I came across a loose bit of bark on the ground and under it were several slugs, the familiar leopard slug, Limax maximus.

leopard slug

This is the common native large slug in woods and gardens. However it is increasingly being overtaken in abundance by the green cellar slug, Limax maculatus. This is a species native to wood in the Caucasus area that was accidentally introduced some fifty years or so ago and is now spreading rapidly.

I

green cellar slug Limax maculatus

One plant that is oddly scarce at Blashford is honeysuckle, so I was pleased to see one of the few plants we do have growing well in magnificent, full flower.

honeysuckle

Lastly a picture of a rare plant in Hampshire, but one that is quite common at Blashford, slender bird’s-foot trefoil, it is flowering abundantly just now.

slender bird’s-foot trefoil

Quiet a “Wild Day” considering I was stuck in the office wrestling with report writing for quiet a good part of the day and also out doing path clearing for part of the day.

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30 days Wild – Day 10 –

I had the best moth catches of the year so far both at home, where the pick was a privet hawk-moth and at Blashford where honours were shared between a small elephant hawk-moth and a scarce merveille du jour.

scarce merveille du jour

The day was warm, although not always sunny, but it was warm enough for damselflies and dragonflies to be flying. The small blue damselflies so far have mostly been azure, but the numbers of common blue seem to be increasing and both can get very abundant at Blashford in good years.

common blue damselfly (male)

I had some mowing to do in the morning in an area where we are trying to establish a grassland and prevent the encroachment of bramble, we are getting there, but it takes time. Cutting at this time or year hits the bramble hard and although it does have an impact upon annual species perennials survive perfectly well and will benefit in the long run. I only cut a small part of the area at any one time, which also helps to minimise the impact. In one of the better areas which I was not cutting I found a single bee orchid.

bee orchid

The management of open areas does not just involve cutting, we also graze some areas and on the lichen heath we have been experimenting with stripping off the top few centimetres of vegetation. This gets us back to the mineral, sandy gravel to see if we can combat the increase in nutrients which is slowly turning it into dry acid grassland. Looking at one of the plots today I think we may have had some success as it was well colonised by one of the areas rarer plant species , slender bird’s-foot-trefoil,  a species that does not seem to like competition.

slender bird’s-foot-trefoil

Once again today I saw a painted lady, this one flying vigorously northwards, so no picture, I did get one of the other migrant butterfly I saw, a red admiral. It was perched on nettle, the foodplant so this one might have had more of a mind to breed than migrate.

red admiral on nettle

The nearest thing to bird highlight on the reserve today was a bar-headed goose, as their native range is other side of the Himalayas I think we can be sure it is an escapee or the descendant of escapees.

I got home, with time to take a quick look in the meadow…………

What’s in My Meadow Today?

I mentioned meadow buttercup yesterday and today I spotted a small yellow and black hoverfly on one of the flowers. It is a common and distinctive species and one that is probably found in gardens all over the country.

Sphaerophoria scripta  (male) on meadow buttercup

My other find was a couple of ants on a flower of common vetch, they seemed to be feeding, at the base of the flower, possibly they had made a hole to get at the nectar flow without entering the flower, as bumblebees will do to runner bean flowers, effectively taking the nectar without doing the job of pollination.

common vetch and ant

Brilliant Volunteers

As I have noted many times on this blog, Blashford Lakes would not be anything like as good a site without the invaluable input from our great volunteer team. Our volunteers help out with a range of tasks and do some projects in their entirety.

Over the last week we have had volunteer educators helping with school groups river dipping in the rain, reptile and butterfly surveyors, office administration and our Tuesday and Thursday working parties.

The rarest habitat at Blashford Lakes is the Lichen Heath, perhaps because of its industrial origin it is not actually designated, but it is home to many nationally rare species which form an assemblage which needs looking after.

Lichen Heath close-up

The importance of the area rests on it having very low nutrients, but over time nutrients fall from the sky and collect in the upper layers of the soil as mosses, lichens and small plants die. The obvious conclusion is that it will slowly disappear and turn into nutrient poor acid grassland. So how to keep some areas to true Lichen Heath? The answer is probably to strip off the surface layer and get down to the bare sandy surface and let it colonise once more. This seems very drastic and it feels wrong to be stripping off what is still a diverse sward with lots of interesting species. We started doing this in a small way on Tuesday, doing six small trial plots which we can monitor, if it looks a good technique we can extend it more widely in the years to come.

Lichen heath before surface stripping

Lichen heath after surface stripping

We chose sites where there were small bramble or birch trees that needed removing anyway and piled up the material on the northern side of the scraped area to provide some variation in the surface topography and potentially warm nesting sites for the many species of bees, ants, wasps etc. that call the heath home.

The rain this last week is what allowed us to work on the heath as it meant the lichens absorbed water and so could be walked on gently, in dry conditions they would just crumble to dust under foot, which is why we ask visitors not to walk on it. Even in wet conditions it is intolerant to trampling so we do as little as possible out there. So it was a treat whilst we were there to see some of the special species that grow on the heath including the two rare bird’s-foot trefoils.

Hairy bird’s-foot trefoil

 

slender bird’s-foot trefoil

On Thursday the volunteers were back on the task of clearing Himalayan balsam and pink purslane from along the Dockens Water. These two invasive alien species can muscle out native species, but can be controlled by pulling them up to prevent seeding. After several years of doing this we have made great progress and balsam is now no more than occasional where once it was the dominant plant. Along the way when doing such tasks we come across other things of interest, one such find was a mating pair of lime hawk-moth.

Lime-hawk moth pair

Some discoveries though are less welcome and one such was an American skunk cabbage plant, the first I have ever heard of along the Dockens Water. This plant has been a big problem in wetland sites across the New Forest and the subject of an eradication program, so finding it here is a worry. I suspect that somewhere up stream someone has it planted around their pond and the seeds are escaping to grow in the wild.

skunk cabbage, a young plant without the huge leaves and yellow flower that attracts water-gardeners.

Our last chance find was made by Geoff, one of our most regular volunteers who photographed this crab spider which had ambushed a bee visiting a daisy flower.

Crab spider with bumble-bee prey on ox-eye daisy.

I will endeavour to do a wildlife update for the week later, I know we have received a number of fabulous photographs from visitors.

 

Sunday Sun, (Eventually)

On Sunday I opened the moth trap for visitors to the reserve, the catch was actually not too bad considering how windy it had been overnight. The highlight was a micro species, Anania verbascalis, which I was only able to identify retrospectively, as far as I am aware it was new for the reserve as well as to me. Unfortunately it was very difficult to get half decent photographs as it was very dull and raining at times.

Luckily in the afternoon it did warm up and the sun came out. I had to mend part of the fence beside the sweep meadow and could not avoid admiring how good it is looking this year.

sweep meadow

It often has a good show of ox-eye daisy, but I think it is the mass flowering of bird’s foot trefoil that really makes it look so good this year. Actually there are four different bird’s foot trefoils growing across the meadow and nearby lichen heath. In the wettest areas there is the tallest one, the greater bird’s foot trefoil, in the general grassland there is the “regular” bird’s foot trefoil, whilst as it gets drier there are patches of slender  bird’s foot trefoil and on the really dry sandy spots there is hairy bird’s foot trefoil. The rarest, at least in Hampshire is the slender bird’s foot trefoil, which seems to be having a very good year this year, with some large patches.

slender bird’s foot trefoil

As I finished repairing the fence I noticed a common toad crossing the path, no doubt tempted out by the morning rain.

common toad

As the sun warmed the insects came out in force. I came across my first bee wolf of the year, in fact several on a sandy patch beside the entrance track.

bee wolf

These wasps capture honey bees to provision their nests, which they dig in the sand, to provide food for their larvae. I also saw several other digger wasps, I only a picture of one and so far I have failed to get a positive identification of it.

digger wasp