Habitats

There are various areas of our ground that I have tried to enhance for butterflies over the last four or five years. I know that this is quite a contentious subject, as habitats constantly evolve – grasslands turning into scrub, scrub turning into woodland and even woodland evolves from birch and rowan trees through to oaks. Each of these habitats is valuable but we often tend to favour one stage over another.

There has been a big push in this part of Scotland to plant trees, but this is often to the detriment of other species. Quite a number of sunny banks where wildflowers once grew are now planted with trees. Even if such areas are left unplanted, then without being grazed they can often be taken over by bracken, heather or thick grasses.

As I have discovered, it takes a lot of work to keep an area frozen in time! Here is an update on some of the projects I have previously written about.

I continue to have to cut the vegetation under the trees annually. Last year the grass cutter was broken down and it is amazing how many small beech, sycamore and willow trees are growing up. I usually leave this until after the first frosts in the hope that any caterpillars will be deep in the grass. The topper is set at about 5 inches, so it still leaves a good cover. The intention with these areas is to predominantly have grassland with wild flowers growing in it.

The area that was a spruce plantation has really greened up well. The spruce were very dense and there was no vegetation growing under them. This is the third year since they were felled and initially there were a lot of annual plants such as woodland groundsel. Last year there were hundreds of foxgloves, which are biennials, and this year there is a lot of grass cover, but also still plenty of wildflowers. The 13 species of native broadleaved trees I planted have mostly reached the top of their tree tubes and there is quite a bit of elder growing between them.

I am seeing a gradual improvement in my wildflower meadow over the years. The ground there appears to be quite fertile, so had a lot of nettles and thistles growing in it, as well as thick, rank grasses. The scythe mower has made a real difference by cutting the grass below the thatch, revealing the soil, which has allowed the wild flowers to come through. I then rake off the hay and pile it up at the side of the meadow. I had left some areas uncut for several years, but they were taken over by wild raspberries and I noticed willow trees seeding in there, so this winter I cut these areas down too. I have also taken off the lower branches of some of the surrounding trees, which will allow a lot more light in. It is interesting that wild flower plugs that I planted two years ago, which I thought had died, have reappeared this year.

Not long after we moved here I was standing at the top of the drive looking at all of the rhododendron growing all over the place. I thought to myself that if I didn’t start removing this invasive species it would soon take over the whole place. My wife and I have put a lot of work into removing it and I have sown wildflower seeds where it was. Although it must provide some shelter birds don’t tend to nest in it, the leaves are toxic and apparently the nectar is toxic to bees, it spreads quickly preventing other plants from growing, it can also host a fungus which kills oak and larch trees. So it is a plant that I am keen to remove. There are still acres of it to get rid of and I want to plant something like holly to provide shelter and nesting spaces.

And here is a picture I took from the same spot today.

One of my smaller projects was a bit of an experiment to see if I could get rockrose to grow on a bank close to the house. I took cuttings from wild plants further up the valley and have successfully produced ten healthy plants. These were planted out four years ago and have done well. Two years ago I was amazed to see a Northern Brown Argus in the garden. This year I saw another Northern Brown Argus, but this one was closer to the rockrose. It stayed around for a few days and later I spotted eggs on the rockrose, so it looks as though I may have my own mini colony of Northern Brown Argus. So, next spring I will take a lot more cuttings and hope to expand the area of rockrose.

The wildflower meadow is in quite an exposed area, so I decided to plant a mixed hedge almost six years ago. You would think it would be a good solid hedge by now, but sadly events conspired to restrict its growth! First the neighbour put cattle in his field and they just reached over the fence and pulled up the young plants! An electric wire prevented that happening again, but later his sheep managed to push the fence over and they gave the hedge a good prune! Initially I used plastic spirals to protect the young plants, but they were inadequate to stop rabbits and deer eating the plants. So, I invested in some wide shrub tubes. With a new sheep-proof boundary fence the hedge has done well this year for the first time!

The hedge is a mix of hawthorn, blackthorn, crab apple, hazel, guelder rose and alder buckthorn. These were mostly chosen because they will provide flowers and fruit for wildlife. Alder buckthorn is the food plant of the caterpillars of Brimstone butterflies and although the butterfly doesn’t exist in Scotland, other than the odd visit, I hope that one day a passing Brimstone may find my plants! This has actually sparked off a project that I will write about in a future post.

A lot of work has gone in to all of these projects, but it has all been very enjoyable and rewarding.

Peacock caterpillars, Aglais io

After a cooler than normal April and May and a cloudy June I was worried by the low number of butterflies I had seen in the spring. I wondered if they would have an opportunity to breed and despite searching patches of nettles I hadn't noticed any nests of Small Tortoiseshell or Peacock butterflies. Normally, they are quite obvious.

Much to my relief on the 19th July I found some Peacock caterpillars on nettles in my meadow. It was just the one patch, rather than the normal two or three groups of caterpillars of both Peacocks and Small Tortoiseshells.

I kept an eye on them for a few days and by the 26th July they started to disperse a bit, so I collected two caterpillars to rear in a cage away from predators.

I was amazed by how active they were and how much they ate, requiring a new nettle stem each day.

By the 31st July one had formed into a chrysalis and the other was hanging from a silk pad it had spun on a leaf stem.

On 1st August I carefully carried the jar with nettle stem outside to photograph. I then put it back in its cage and when I looked ten minutes later its skin had split and it was starting for form a chrysalis. Yet again, I missed the actual moment when the skin split!

On the 13th August the first chrysalis emerged. It was the same story. Earlier in the day I had checked the chrysalis and when I checked ten minutes later there was a butterfly!!

Normally the chrysalis darkens a couple of days before the butterfly is due to emerge and the pattern of the underside of the wings can be seen. This give a pretty good indication of when the chrysalis will emerge. An hour-or-so before emergence the abdomen section of the chrysalis lengthens slightly and you can see the gaps between the segments pull away from the chrysalis as seen in the picture below.

The following day the second chrysalis emerged, again without me actually experiencing it! I am not complaining though, as I did witness this happening two years ago.

Painted Lady, Vanessa cardui

I have only seen a Painted Lady laying an egg on three occasions. The first time was on a Creeping Thistle in a horse field, so I picked the thistle leaf and decided to raise the caterpillar on a thistle at home in my garden. Sadly a few days after hatching we had torrential rain and I never saw the caterpillar after that.

Two years ago I saw a Painted Lady lay and egg on a Woodland Groundsel plant in my woods. I marked the plant and kept an eye on it, but two days later we had torrential rain again and the egg disappeared. I searched the ground around the leaf it had been on, but couldn’t find the egg.

This June, when I was up in East Lothian I watched a Painted Lady as it laid several eggs on a Spear Thistle at the side of a path. I decided to pick one flower head and try raising the butterfly in the safety of a cage at home. The picture below was taken on my work phone. The others were all taken on my Samsung phone, so not the best of quality, but they give an idea of the different stages.

Seven days later, on the 6^th July, I noticed that the egg had hatched, but despite searching the flower head for ages, I couldn’t find a caterpillar anywhere. 

Three days later I found it at the base of the flower. At this stage it was dark brown with three rows of three yellow spines.

I picked a stem of Creeping Thistle and put it in a jar of water with a hole in the lid, but the caterpillar didn’t seem to like this, so I tried a much less palatable-looking Spear thistle and it happy ate that!

I then realised that I had two caterpillars, so there must have been another egg on the flower. Unfortunately, though I wasn’t thorough enough checking the leaves and I discovered that I had introduced a Flower Bug into the cage, which devoured one of the caterpillars. I didn’t know anything about these creatures, so I looked it up and discovered that they area a “gardener’s friend”, as they kill aphids and caterpillars by piercing their skin and sucking out the contents!

The remaining caterpillar munched its way through several leaves, but didn’t seem to have as much of an appetite as the Red Admirals or Peacocks I was rearing at the time.

After going through various very attractive instars the caterpillar left the thistle on the 25^th of July and made its way up to the top of the cage, where it spun a silk pad and hung in a J-shape for a couple of days.

Two days later it had formed a beautiful chrysalis.

It only remained as a chrysalis for 12 days and it emerged as a butterfly on the 8^th August.

Once it had dried its wings I took it outside into the afternoon sun. Almost immediately it took off and flew across the orchard never to be seen again!

I checked my Buddleia plants daily and it wasn’t until the 5^th of September that I saw another Painted Lady. I had quite a few regularly feeding until late September when the weather started to cool down.

Red Admiral, Vanessa atalanta

On 22nd June I was working in my study when I notice a butterfly out of the corner of my eye. I am easily distracted that way, so looked round and saw it was a Red Admiral and it was inspecting the nettles right outside my window. I spotted it laying an egg and, as I have mentioned before, my study window looks out on the hen run, so I doubt any caterpillars would last long.

At lunchtime I popped out and picked the nettle that the egg had been laid on. I kept it in a jar of water with a hole punched through the lid. All of these photos were taken with my phone. This one was taken looking through a microscope.

Seven days later the egg hatched, but I couldn't find the caterpillar. After three days I spotted it in the young shoot at the top of the nettle stem. It stayed there for another five days in a sort of web it had made and once it had eaten most of the young leaves it moved to a larger leaf further down the stem, where it started constructing a tent.

I kept putting fresh nettle stems in the jar and I noticed that the caterpillar would spend the day inside its tent. The following morning I would find the tent completely eaten and a new tent formed on the new stem. This happened for a further 19 days during which I didn't see the caterpillar.

On the 25th July no new tent had been formed and I managed to see the caterpillar hanging in a characteristic J-shape inside the leaf tent. The following day it had formed a chrysalis and I was able to open up the tent to get a better look.

It remained as a chrysalis until the 8th August, when it emerged as a butterfly. Over the previous two days the chrysalis darkened and I was able to make out the pattern of the top sides of the wings. A couple of hours before it emerged I could see the abdomen section of the chrysalis lengthen slightly, however, I still managed to miss the actual point of emergence!

So, it was seven days as an egg, 26 days as a caterpillar and 13 days as a chrysalis.

This is an almost identical story to the Red Admiral egg that was laid in the hen run last year. On that occasion the egg hatched after only four days, it also remained as a caterpillar for 26 days and it remained as a chrysalis for 16 days.

Once its wings had dried I took the butterfly outside. It spent a while warming up in the sun, then took off and did a couple of laps of the patio before flying off to join the other Red Admirals on the Buddleia.

Sierra Nevada, Spain Flora

I remember back in 2014 before I went to the Sierra Nevada I asked for information about good walks there where I would be able to see butterflies. I was surprised when the recommended walk was up at the Hoya de la Mora carpark, which is over 2,500 metres up in the mountains.

I was told it was a great place to find Zullich’s Blues, Sierra Nevada Blues, Spanish Brassy Ringlets and various other endemic or rare species. A look at Google aerial views showed a very baron, rocky environment. I was particularly surprised that I was also told that July was the perfect time of year to see butterflies, thinking that it would be particularly hot and dry then.

What I didn’t take account of was altitude. What I discovered when I visited was that at 9am it was only 10 degrees Celsius at Hoya de la Mora, rising to 17 degrees by midday. Only 15 kilometres away in Granada the temperature was over 35 degrees.

Hoya de la Mora is a popular ski resort and for seven months in the year is covered in snow. Even in July there are odd pockets of snow in shady spots.

All of this makes the high Sierra Nevada mountains a unique habitat supporting a very interesting variety of flora. It wasn’t until I started walking that I notice all of the small plants tucked into cracks in the rocks. Here are a few examples that I have tried to name, although I am no expert.

I was very intrigued to see what looked like Kidney Vetch, Anthyllis vulneraria, but instead of the yellow-flowered plant I am used to seeing on the east coast of Scotland, in the Sierra Nevada it is pink. I think this is the subspecies arundana, although there are other pink subspecies found in mountain ranges across Europe.

One of the many lovely cushion-forming plants I saw is Arenaria tetraquetra, which I think is endemic to the Sierra Nevada.

The plant below is a Cerastium species. There are many very similar species. An endemic of the Sierra Nevada is Cerastium alpinum ssp. nevadan, but I can't be sure that this is what this one is.

I am a great fan of Dianthus, so I was delighted to see this one dotted around the rocks there. I think it is Dianthus brachyanthus, although there seem to be many different names given for species and sub-species depending on which book or website you look at!

This is Erodium cheilanthifolium, which is found on many mountain ranges in Spain.

There was a lovely white Rockrose growing amongst the rocks and scree. I think this is Helianthemum apenninum, which is said to occur in the Sierra Nevada, although there is another very similar-looking Helianthemum almeriense that occurs in southern Spain.

Back in Scotland I have spent many hours searching Rockrose for the eggs of Northern Brown Argus. I didn't think to have a look to see if there were any eggs on this white Rockrose!

A plant that I have specifically looked for on each visit to the Sierra Nevada is Androsace vitaliana, which is the food plant of the Zullich's Blue caterpillar. As with so many other plants there is a subspecies, nevadensis, which occurs in Sierra Nevada and it is only found above 2,400 metres. I have only ever found it on very loose scree on exposed, windswept slopes.

In these same areas I have seen this lovely little pink flower, Nevadensia purpurea. It forms lovely cushions, covered in flowers and only occurs in the Sierra Nevada.

Another lovely little prostrate flower found high in the Sierra Nevada is Leontodon boryi, which also appears to be endemic to the Sierra Nevada.

Jurinea humilis gave a lovely splash of colour on some of the exposed slopes. It is found over much of Spain above 1500 metres.

There were so many other flower amongst the rocks and scree and I mostly photographed those that were in flower. I believed that over 2100 different species of plants have been recorded in the Sierra Nevada, so what I saw was only a fraction of those. Just a few more!!

The Sierra Nevada Violet, Viola crassiuscula, seemed to be quite common along the side of the paths that I walked on. Yet again, this plant is endemic to the Sierra Nevada.

I particularly liked the Sempervivum vicentei, which squeezed into small cracks in the rocks.

I was intrigued by this woody plant that I spotted between two large rocks at the bottom of a scree slope. It is Prunus prostrata, a little cherry tree!

This prostrate Juniper, Juniperus sabina, was quite common in some areas. It gave off a lovely scent when I brushed against it trying to get pictures of butterflies!!

Not all of the area up there was so bare and rocky. Next to a stream and in damper areas below springs there were green areas of grass with wild flowers.

These areas supported a variety of flowers. The most striking was a gentian, Gentiana sierrae. This only occurs in Sierra Nevada and Sierra de Baza.

They were often seen near Pinguicula nevadensis, an insectivorous plant which is endemic to the Sierra Nevada.

So many of these species are only found on the Sierra Nevada mountains and they are quite vulnerable to erosion. I noticed this summer when I was there that the National Park have blocked off some of the paths and are encouraging walkers to stick to the main paths. They are also preventing cyclists using the rough paths, asking them to stick to the road, to try to reduce erosion of the mountainside.

I was always very conscious not to stand on any plants and often I felt as though I was in the middle of an amazing rock garden!

Further down the mountains by about 1500 metres above sea level there were a lot more shrubs and trees and the flowers there are taller and very similar to what can be found in other areas of meadow in Spain.

I can highly recommend the WASTE Magazine website, where I have found so much useful information about the flora and fauna of Sierra Nevada and southern Spain. It was Merche from this website who first recommended that I should visit Sierra Nevada to look for butterflies.