Blog - butterflies
Where do butterflies come from?
An obvious answer to this question would be - caterpillars. But when did butterflies first appear? There are now some 160,000 species of moths and butterflies -worldwide. Seemingly, they appeared some 100 million years ago - in North America. They evolved from nocturnal moths in the period when flowering plants were undergoing a major expansion (in the Cretaceous period). Butterflies may have become diurnal to avoid predation by bats, or it may have been to take advantage of nectar production and availability [using the proboscis]. The butterflies and their caterpillars were able exploit the diverse range of food resources that these ‘new’ plants offered. Butterflies moved out from North America to South America and then on to other parts of the world, though they probably did not arrive in Europe until some 17 million years ago. The evolutionary expansion of the butterflies has been investigated by researchers at the University of Florida; they analysed the genetic makeup of many species (from 90 countries). They were able to build up a picture of the relationships between the various groups of butterflies and also determined their evolutionary point of origin. They also catalogued the plants eaten by the caterpillars and it was found that some two thirds of butterfly caterpillars feed on plants from the legume family (the Fabaceae - peas and beans). It is probable that the first butterfly caterpillars also fed on these plants. Research at the Georgetown University in Washington DC suggests that larger species of butterfly are ‘coping’ better with higher temperatures, associated with global warming. Bigger wings seem to offer a greater range of movement and the opportunity to find new and suitable habitats. Smaller butterflies are not faring so well. The study involved an analysis of the range of some 90 North American species between 1970 and 2010, during which period the monthly minimum temperature increased by 1.5oF. Others have analysed the butterfly collections at the Natural History Museum, using digital technology. The Natural History Museum’s British and Irish butterfly (and moth) collection is probably the oldest, largest, and most diverse of its kind in the world; some of the specimens date back over a hundred years The measurements of the various specimens were paired with the temperature that the species would have experienced in its caterpillar stage. It was found that for several species that the adult butterfly size increased as the temperature increased (during late larval stage). So, it may be that we will see a gradual increase in butterfly size as temperatures increase with global warming. Join the Big Butterfly Count ? Between Friday 14th July and Sunday 6th August , the big butterfly count will take place. For full details visit : https://bigbutterflycount.butterfly-conservation.org/about Thanks to Angus for images.
A very special visitor.
The first few weeks of owning a patch of woodland feel like the beginning of a long and special relationship. Every discovery is new; each adventure a first. A wood reveals it secrets slowly. We’ve already tramped round every corner of the wood, tearing our shins on brambles, sniffing at fungi, clambering round stumps and totting up the oak, hazel, maple, cherry and rowan that thrive under our canopy of pine and larch. We’ve sat and looked and listened in all weathers, at every time of day. Starting a list of birds was the first thing to do: a mewing buzzard overhead, marsh tits pitching in the roving tit flock, the tap of woodpecker and nuthatch. Autumn – though this year so mild and late – soon announced itself with a first skein of pink-footed geese calling high and unseen over the wood, the first redwing chattering at the wood edge… sounds and colours change; the big wheel keeps on turning… We have always loved moths, for their beauty, their ubiquity, their astonishing variety. Moths range in size from the tiny micros whose larvae leave scribbled signatures across the leaves in which they live, to the powerful hawkmoths or that mythic blue-underwinged beauty the Clifden Nonpareil, a creature practically the size of a small bat, and probably the most sought-after moth among the old collectors with, in some years, just a single individual found across the country. For there’s also a rich and often eccentric history of moth recording in this country with most of the larger moths – the macros - having evocative vernacular names (though don’t confuse your Bright-line Brown-eye with a Brown-line Bright-eye!), and an array of techniques for acquiring them from pupa digging, plastering tree trunks with mixtures of treacle and rum, to light. Nowadays, moths are generally photographed and released rather than pinned; recording them is an excellent way of assessing the biodiversity of a site or tracking population changes. It was clearly time to break out the old moth trap. And so it was that this September for the first time in years we dusted down the generator, filled the trap with fresh egg boxes for the anticipated moths to settle on, spread out our white sheet in a promising looking glade, and hoped to goodness that our 125W mercury vapour bulb would still fire up after all these years… As night came the light shed unfamiliar shadows through the wood; we waited, net in hand, taking care not to look directly at the blazing UV light; waited with a palpable sense of anticipation… what secret would the wood reveal? At first, nothing. And then a first furtive fluttering across the clearing to the trap – probably a Common Marbled Carpet though I’d have to check – and a plumper-bodied moth, and me there wracking my brains: it’s a noctuid, sure, but I’m so rusty – what’s-it-called? Flame? Flame Shoulder? Setaceous Hebrew Character…? ‘What the hell was that?’ said Beth Something ridiculously large had flapped out of the shadows and vanished. Knelt at the trap, I’d glimpsed it too from the corner of my eye. Could it be a hawkmoth on our very first trap, that would be very cool! I grabbed the net; we stood back and waited. I knew we had something beyond the ordinary when Beth yelled ‘There it is!’ and I swung the net and captured it on a second sweep. It was big all right! Anxious not to lose our catch, whatever it was, we shut ourselves in the toolshed and peered into the gently-opening net with our torch… The moth was the shape of a vulcan, practically size of a small bat, and more beautiful than anyone can do justice to: a marbled, lichenous beauty, zig-zagged and pocked and dabbed with greys and whites and blacks and – look! – when those forewings flick open an underwing black and banded with an impossible flash of blue… ‘It’s a Blue Underwing,’ we cried, ‘A Clifden Nonpareil…!’ An entry in my Aurelian’s Fireside Companion describes the experience soberly: ‘For a moment or two we gazed at it in speechless admiration, fearing almost to breathe lest it take flight…’. I suspect we used a few more expletives than that! And what a secret to reveal; our first trap in the new wood and we caught probably the best moth we could ever hope to find. One truly without compare. Soon after the generator packed in; we were plunged into darkness. 2022, it transpires, has been a record year for Clifden Nonpareils, as it has been for many rare moths. Our Nonpareil could have been a wanderer from further south in England where a population has now reestablished itself on aspen and poplar after decades of extinction – or (and I find this the more romantic possibility) it could have been a migrant from the east, flapping its way across the North Sea to our northerly inland wood, and revealing itself, albeit briefly, to its astonished and delighted admirers… By torchlight, we placed the moth on a tree stump, astounded to see something we’d always dreamt of finding. It sat there for a moment, as though contemplative, then showed a flash of blue petticoat as it shivered its huge and brindled grey wings. Shivered again. And flew off into the night. What will the seasons bring?
The Big Butterfly Count : findings
The results of this year’s Big Butterfly Count have now been published and the ‘top’ 5 butterflies are the gatekeeper, the large white, the small white, the meadow brown and the red admiral. The count is a UK-wide survey that aims to provide a measure of the state / health of our environment by simply counting the number and type of butterflies (and some day-flying moths) we see in our gardens and parks. The good news is that the Gatekeeper is making something of a comeback, being the most spotted butterfly in the count. The numbers of the Common Blue, Holly Blue and the Comma are also ‘on the up’. The Comma has been making a slow comeback for some years. This is associated with the Comma extending its range northwards. Extension of range is also seen in the Holly Blue, it is thought to be associated with climate change. Some twenty years ago, it was rarely to be seen in Scotland, but it was recorded in Edinburgh in 2006, then Ayr in 2008 and now has spread across large areas of Scotland. [caption id="attachment_24954" align="aligncenter" width="600"] Comma butterfly : photo by A J Symons.[/caption] The Jersey Tiger Moth is another species that is extending its range. Once it was to be found on Devon’s south coast, but it has spread north and east. It is now to be seen in gardens and parks in the Greater London area. These moths ‘like’ gardens, hedgerows and disturbed / rough ground. In coastal areas, they may be seen on cliffs and the upper reaches of a beach. The caterpillars of this moth feed mainly on ground ivy, white dead-nettle, bramble and the common nettle. There are differences between butterflies and moth, but there is no hard and fast rule to distinguish between them. Butterflies usually have ‘club-shaped’ antennae, whilst many moths have feathery or tapering ones. Butterflies normally fold their wings vertically over their backs, moths generally place their wings horizontally when at rest (but not all). Whilst this summer’s results offer some hope, and the warmth of this summer’s weather might be thought to have favoured butterflies, the overall trend / pattern of butterfly numbers is one of decline - for example, numbers of the Red Admiral and Meadow Brown are down, sadly a pattern seen in many insect species. The loss of suitable habitats, such as meadows and hedgerows, is thought to be a major factor in this decline.
Ragwort is a common wild flower. Its common names include, common ragwort, stinking willie and tansy ragwort (though its resemblance to true tansy is rather superficial). It is not particularly a woodland plant, it is found in dry, open places - on waste land, waysides and (grazing) pastures. It is not a plant favoured by land owners because it has toxic effects on cattle and horses. It is generally considered to be a biennial, but can persist for some years. The stems are erect, straight, basically hairless. The actual plant may grow to a height of two metres. The leaves are lobed in a ‘pinnate’ fashion and have a distinctive smell that has lead to some of its common names - such as stinking willie. The ragwort is a member of the daisy family (Compositae, now the Asteraceae), and its flowers are massed together into dense, flat topped clusters. Each ‘flower’ is made up of many small, individual florets. In the centre are the disc florets whilst around the edge are the ray florets. The latter have a large lip or flap, which serves to increase the visibility of the plant to pollinators. During the flowering season, a plant may produce many thousands of seeds. The seeds have hairs attached to them, which help in dispersal. Ragwort is a plant that is much loved by pollinators - bees, flies, moths and butterflies. It is generous in its nectar production, and has been placed in the top ten of nectar producers by one survey. The plant also provides home and / or a food source for many invertebrate species, some of which feed on ragwort exclusively*, including some species on the IUCN RED LIST. One species that is reliant of this plant is the cinnabar moth, whose status is described as ‘common and widespread, but rapidly declining”. Interestingly, the cinnabar moth feeds on the plant absorbing the alkaloids and these make it distasteful to its predators . However, important as the plant is in ecological terms, it is toxic as it contains a number of alkaloids. These are poisonous to various animals, such as horses and cattle. The bitter taste is a ‘disincentive’ to much of the plant being eaten. However, because of the alkaloids, it is one of the five plants (in the UK) named as ‘an injurious weed’ [as defined by the Weeds Act of 1959]. Some people may suffer an allergic reaction after handling the plant, experiencing a form of dermatitis. [caption id="attachment_38929" align="aligncenter" width="675"] Cinnabar moth, image courtesy of mcbeaner on Pixabay.[/caption] [caption id="attachment_38599" align="alignleft" width="300"] Cinnabar caterpillar[/caption] [caption id="attachment_38566" align="alignright" width="300"] Leaves of Ragwort[/caption]
Big Butterfly count 2021.
Butterfly Conservation has organised the Big Butterfly Count for the last twelve years. This year, the count took place between 16th July and August 8th. The count gives some information of how butterfly and moth populations are faring. Both butterfly and moth numbers give us some information about the ‘health’ of our environment, and indeed what has been termed the insect apocalypse. Though some 150,000 counts were registered this year, the ‘average’ number of butterflies / moths recorded per count was nine. This was down from the average count of 11 last year, and 16 in 2019. The total number of butterflies / moths counted was down by some 14% overall compared to last year. Those species that had significantly reduced counts were Peacock down by 64% Common Blue down by 59% Speckled wood was down by 41% Small tortoiseshell and the Comma dropped by 32% On a more positive note, the ringlet and marbled white were recorded in greater numbers (but they did have low counts last year). The Spring weather was probably a significant factor in these generally disappointing results. The wet May would not have helped breeding or feeding; low temperatures are not conducive to activity. The poor weather would particularly impact on those species that normally produce two broads a year. Further information on the results of the count can be found the Butterfly Conservation website : here.
Woodland web updates (3).
Big Garden Birdwatch. Once again the RSPB’s Big Garden Birdwatch is about to swing into action. This year , it will take place from the 29th to the 31st of this month. To take part, you just need to count the birds that you see in one hour. Details and guidance are available here : https://www.rspb.org.uk/get-involved/activities/birdwatch/everything-you-need-to-know-about-big-garden-birdwatch/ Butterflies (and moths). If you are interested in adding to your knowledge of wildlife, then the Butterfly Conservation people not only offer guidance on identifying moths Read more...
A sting in the tale?
Stinging nettles (Urtica dioica) are widespread across the UK. They are found nearly everywhere; in woodlands, hedgerows, gardens and on disturbed ground. Nettles have been found in and around human settlements since the earliest of times; they probably formed part of the diet in Stone Age times. Nettles also provided fibre for clothing. A piece of nettle cloth has been found in Denmark's richest known Bronze Age burial mound (Lusehøj). It is associated with the burial of a rich and powerful man - after the burning of his body, his bones were wrapped in a cloth made from stinging nettles and then placed in a bronze container. Stinging nettle pollen is often to be found in soil sample cores, suggesting it is one of our native plants though human activity and movement may helped it to extend its range. Nettles can tolerate a wide variety of soil conditions, though they seem to like moisture, and soils rich in nitrate and phosphate. In favourable conditions, they can grow to a metre or more in height. There are patches of stinging nettles that mark phosphate-rich debris from abandoned villages and sites of human occupation from more than 1500 years ago. Nettles have the potential to grow and expand in woodlands, perhaps aided and abetted by the increasing levels of eutrophication (nitrate / phosphate enrichment from air borne pollution). Indeed, they can become 'botanical thugs' overwhelming other members of the ground flora / herb layer. Read more...
‘Verging on the ridiculous?’
It is clear that wildlife is in decline, not just in the U.K, but across Europe, America - in fact wherever you look. Over the last century, over 90% of meadows have been lost in the U.K. This decline in natural habitats / ecosystems is largely due to urban growth and the expansion & intensification of agriculture. Concomitant with the loss of natural habitats is the loss of wildlife. One particular cause for concern is the ‘disappearance’ or decline in numbers of some many insect species, especially pollinators. The woodlands blog has reported many times on honeybee and bumblebee numbers.` Pollinators, such as bees, butterflies or hoverflies, need to find food (nectar & pollen), plants on which their larvae can feed, sites for nesting, reproduction and over-wintering. With the growth of cities and agriculture there has been an expansion of transport networks, particularly roads. There are more than 30,000 miles of major roads in UK in 2019, with some 2,300+ miles of that being motorways. Roads clearly have a number of ecological impacts (dividing up the landscape being one) but they also offer ‘habitats’ alongside the road. Read more...