20th May - Martin Down & Bentley Wood, Hampshire: Butterflies, Moths and Dragonflies

Part two of the day at Martin Down doesn't really start until we came back off the Jubilee Trail and turned left to walk the Ditch again.  Here you walk through a small clump of bushes and climb a hill, on the right hand side is a sheltered spot and is usually in full sun, it is always worth checking as the butterflies have the opportunity to warm up and can be found quite early in the morning.  Today was no different.  As I walked around staring at the ground a caught a flash of blue from the corner of my eye.  At first I thought I had imagined it, but then it appeared again, it settle down and opened the wings, the first butterfly of the day, and also the first blue of the year was a smart male Adonis Blue.

The males have brilliant sky-blue wings, while the females are chocolate brown and far less conspicuous. Both sexes have distinctive black lines that enter or cross the white fringes of the wings.

The males have brilliant sky-blue wings, while the females are chocolate brown and far less conspicuous. Both sexes have distinctive black lines that enter or cross the white fringes of the wings.

The Adonis Blue overwinters as a caterpillar; and they feed on Horseshoe Vetch during the day. It is most commonly seen during April and late July as it searches for ants to 'milk' its sugary secretions.

In April-May and July-August the caterpillar forms into a chrysalis in small crevices or hollows and is then buried by ants in earth chambers connected to the ant nest. The ants constantly attend to it for around three weeks, protecting it from predators.

A good start to the first real butterfly day of the season, next was a Grizzled Skipper always a good looking butterfly to find at this time of year.

The Grizzled Skipper is a characteristic spring butterfly of southern chalk downland and other sparsely vegetated habitats. Its rapid, buzzing flight can make it difficult to follow, but it stops regularly either to perch on a prominent twig or to feed on flowers such as Common Bird's-foot-trefoil or Bugle. It can then be identified quite easily by the checkerboard pattern on its wings.

Usually seen before the Adonis Blue, the Common Blue butterfly was next.

The Common Blue is the most widespread blue butterfly in Britain and Ireland and is found in a variety of grassy habitats.

Water droplets on the blades of grass following the overnight rain

Unlike Adonis and Chalkhill Blues, the dark veins do not extend into white fringes of wing margins.

As we walked the butterflies seemed to increase, the most numerous on the day was the little Brown Argus, in flight it can be confused with a skipper or the even smaller Small Blue, as the adults have a silvery appearance as they fly low to the ground, but once settled it is easily identified.

The Brown Argus is characteristic of southern chalk and limestone grassland but occurs in a variety of other open habitats as far north as north Wales and Yorkshire.  The Brown Argus is a member of the "blues" family, but unlike most other "blues", the Brown Argus has no blue scales on its upperside, both sexes being primarily brown in colour as its common name suggests, although the butterfly does exhibit a blue sheen when at certain angles to the light. 

Next up along the ditch was the Small Copper, another of those butterflies that just seems to appear.

The Small Copper has bright orange forewings with dark brown spots and a thick, dark brown margin. It has dark brown hindwings that are banded with orange.

Males are territorial and can be seen basking on bare ground or rock waiting for females, every now and again chasing off other insects that encroach on their space. 

The Small Copper is on the wing throughout the summer between April and October. They can have up to three broods in the year.  

Brown Argus were almost everywhere, probably the most I have seen in any place at one time.  Ian found a pair on a grass stem, initially alongside each other..

But they then turned and began to couple and mate.

The Brown Argus generally has 2 broods a year in central and southern England, with only a partial second brood in north Wales and the north of England. In good years, a partial 3rd generation may appear in the south. The adults emerge first in central and southern England in early May, peaking at the end of May and beginning of June, and giving rise to a second brood that emerges at the end of July and into August

When courting, the males congregate at the base of a slope where they either perch, waiting for a virgin female to fly by, or patrol the area looking for a female perched on a grass stem awaiting a mate. Mating takes place after a short flight low to the ground. When egg-laying, the female will make meandering flight close to the ground, searching out suitable foodplants on which to lay.

on the last visit two weeks ago I managed a brief view of a Dingy Skipper, but was never able to capture a photograph.

Despite its name, a freshly-emerged Dingy Skipper reveals a subtle pattern of browns and greys that is quite beautiful. However, this butterfly does live up to its name as scales are lost over time, resulting in a lackluster and drab appearance. 

The next crossroads is where the ditch crosses with the bridleway known bizarrely as Bowling Green Lane.  Despite the name it is a very narrow track and where the ditch path crosses there is a nice open sheltered spot and it was here that we found the first Small Blues.

This is the UK’s smallest resident butterfly with a wing span that can be a little as 16mm and is easily overlooked, partly because of its size and dusky colouring, but partly because it is often confined to small patches of sheltered grassland where its sole foodplant, Kidney Vetch, is found.

Males perch on small shrubs or grass stems which they leave when investigating passing insects or when searching out nectar sources. They are not territorial, however, and can often be found in small groups of two or three.

The sexes are similar in appearance, although the male upperside is almost black with a dusting of blue scales, whereas the female is more dark brown in colour. Both sexes have an underside that is silvery-grey in colour, and not unlike that of the Holly Blue. 

On reaching the rifle ranges we went in search of a Green Hairstreak we had been told of.  This involved searching the gorse and small clear chalk pits while being scolded by a pair of Stonechats, but with no success in finding the elusive butterfly.  

Rather than walk on we decided to turn back and follow the ditch back to whence we had come.  The target species was the Marsh Fritillary and it was surprising we had not encountered any so far this morning.  This time last year they were reaching the end of their flight, but with every thing late this year we expected to find some, but as yet nothing.

A Holly Blue appeared around the May blossom and provided a brief view amongst the white flowers. This is the blue butterfly most likely to be found in gardens, as well as woodlands, parks and churchyards. It tends to fly high around bushes and trees, whereas other grassland blue butterflies fly low to the ground. 

A little further along we had better views as one appeared in the ditch.

The Holly Blue emerges in early spring, from March to May, and then again at the end of the summer between July and September. The foodplants of the caterpillars are mainly Holly (for the spring generation) and Ivy (for the summer generation), although a wide range of other plants are used including spindle, bramble and gorse.

In previous years at this time of the season Small Heath are normally plentiful, but it wasn't until the return walk that we found our first of the day.  An inconspicuous butterfly that flies only in sunshine and rarely settles more than a metre above the ground. Its wings are always kept closed when at rest. 

We had searched for Green Hairstreak around the rifle ranges without any luck earlier and Ian commented that they can turn up when you would least expect them to, and that was exactly what happened.  We stopped at the cross roads with Bowling Green Lane and spent sometime just checking the grass when Ian had a Green Hairstreak drop out of one of the gorse bushes.

The Green Hairstreak is the most widespread of our hairstreaks. However, it is also a local species, forming distinct colonies which can be as small as a few dozen individuals, although other colonies can be much larger.  There is some indication that this year will be a good year for the Green Hairstreak, something that was reinforced by the number we saw on the walk, five which is the highest I have seen here at Martin Down

The Green Hairstreak holds its wings closed, except in flight, showing only the green underside with its faint white streak. The extent of this white marking is very variable; it is frequently reduced to a few white dots and may be almost absent, as is the case with this individual.  It regulates its body temperature by tilting its wings appropriately to catch the sun's rays.

Males and females look similar and are most readily told apart by their behaviour: rival males may be seen in a spiraling flight close to shrubs, while the less conspicuous females are more often encountered while laying eggs.

The male of this species is territorial and will have favourite perching sites that it uses to wait for passing females, but will dart out to investigate any passing object. The perches may be on standalone shrubs or part of a hedge and are often reused by different males should the original occupants wander too far. 

The Green Hairstreak can be found in a wide variety of habitats, including hillsides, moorland, chalk downland, heathland, railway embankments and valley bottoms. A common feature of all these habitats is the presence of scrubby plants and hedgerows.  As a result it has the widest range of foodplants of any British butterfly, which includes Bilberry, Bird's-foot Trefoil, Broom, Common Rock-rose, Dogwood, Bramble and Gorse.

As we made our along the ditch the number of Brimstone increased, the males just wizzing by while the females would search the small blackthorn shoots for a suitable place to lay their eggs.

There was a single Orange Tip seen a female.

And the first Cinnabar Moth of the year.

We reached the top of the dyke and enjoyed the view looking back from where we had walked, the hawthorn blossom standing out amongst the lush green of the surrounding fields and grasslands.

Cutting across the open meadow to reach a track back to the car park, we came across a Painted Lady, which unfortunately when disturbed just flew away

We had always planned to go looking for Pearl-bordered Fritillary in the afternoon, but a combination of closed roads and the lack of Marsh Fritillary at Martin Down changed the plan of heading into the New Forest to a trip to Bentley Wood on the Hampshire - Wiltshire border.

The tally of butterflies here at Martin Down was as follows:  Adonis Blue - 1; Common Blue - 5; Grizzled Skipper - 13; Brown Argus - 22; Dingy Skipper - 11; Small Copper - 6; Small Blue - 5; Holly Blue - 2; Green Hairstreak - 5; Small Heath - 3; Orange Tip - 1; Small White - 1; Painted Lady - 1; Brimstone - Many

The journey to Bentley Wood took us through Salisbury and then initially to the wrong place which required a study of OS maps before we found the car park on the Hampshire side.  From the car park you walk back on yourselves to a scrubby area known as the Eastern Clearing, here there is a lot of open space, bracken and small bushes.

There are very small streams that criss cross the area and this made some of the paths a little muddy and damp. Almost immediately an orange yellow moth passed us raising expectation of the the Pearl-bordered Fritillary, but was soon seen to be a moth, a Speckled Yellow to be exact.

The colouration of this moth may vary slightly in the number and extent of the brown blotches on the wings but it remains easily recognisable from other species. Flies frequently during the day, especially in the sunshine.

It wasn't long before our first Pear-bordered Fritillary drifted by, skimming the tops of the dead bracken.

The pearl-bordered fritillary is a striking orange-and-black butterfly of sunny woodland rides and clearings. It gets its name from the row of 'pearls' on the underside of its hindwings.

It is often seen flying close to the ground along sunny woodland rides or feeding on spring flowers such as common dog-violet. It can also be found in habitats with a mosaic of grass, bracken and scrub. 

It is the earliest fritillary to emerge in April and may even have a second brood if the weather is good. The female lays single eggs in bracken or leaf litter close to violets, the foodplant of the caterpillars.  

We came across another but on approach it flew off, however close by was a Marsh Fritillary, sitting on a small bush.  The day's butterfly targets complete.

The Marsh Fritillary has the most colourful uppersides of all of our fritillaries, being a highly-variable chequered pattern of orange, brown and yellow markings. The bright colours fade after a few days and leaves the butterfly with a shiny appearance.  

The Marsh Fritillary uses several different types of habitat, including chalk hillsides, heathland, moorland and damp meadows. A factor common to all habitats is that they are in full sun, their higher temperature aiding larval development.  The network of small streams and boggy patches is ideal here at Bentley

The Marsh Fritillary was once widespread in Britain and Ireland but has declined severely over the twentieth century. The Marsh Fritillary populations are highly volatile and the species requires extensive habitats or habitat networks for its long term survival. 

Colonies of this butterfly are known to fluctuate wildly in numbers. It may be present in some numbers one year, for the population to crash the following year before recovering as unexpectedly. This species does not do well in adverse weather conditions and also suffers greatly from larval parasitism by an Apanteles species of wasp.

As for most butterfly species, the males emerge a few days before the females and set up small territories centred on a particular plant or flower. They will dart up to investigate any passing butterfly flying nearby. They will also patrol suitable areas, in the hope of finding a newly-emerged female. Once a female is found, the male flutters around her for a short while before mating takes place.

It flew from the bush and settled low in amongst the bracken, I moved some of the vegetation to get a better view and was able to get the butterfly to settle on my hand. This behaviour and the fact that it was in immaculate condition led us to believe that this was a newly emerged butterfly.  It could be then that the colony at Martin Down is yet to emerge due to the cold spring conditions, or as mentioned above they have suffered a crash due to the drought and high temperatures last year.

We wandered around the clearing with at least three Willow Warblers singing, we also had a Hobby fly through which was a surprise.  With the boggy conditions it was no surprise to find dragonflies, only one species and sex, female Broad-bodied Chasers.

The Broad-bodied chaser is a medium-sized, broad-bodied dragonfly that is on the wing from May to July, and occasionally into August. It is a common dragonfly of ponds and small lakes. It regularly returns to the same perch after swift flights out across the water looking for insects

A close up showing the detail around the wing structure and connection with the thorax

The broad, flattened body of the Broad-bodied chaser is distinctive and makes this dragonfly appear 'fat'. The male has a powder-blue body with yellow spots along the sides and a dark thorax; the female is greeny-brown with yellow spots.

Again a close up of the head and thorax.

It was warm and there was no sign of anymore Marsh Fritillaries and the Pearl-bordered were on the wing all the time, rarely settling long enough for photographs.

We made one final circuit of the clearing and came across this male Brimstone nectaring on the bluebells.

The Brimstone is a fairly large, pale yellow butterfly, with distinctive, leaf-shaped wings.

They can be found in damp woodlands, along sunny, woodland rides and mature hedgerows, and in large gardens. The foodplants of the larvae are buckthorn and alder buckthorn. Both shrubs are found in wet woodland, while buckthorn also occurs on dry chalk and limestone soils.

And so the day came to an end, it was the first real butterfly day of the year and has delivered some quality sightings.  I am really pleased with the performance of the camera and lens, the images coming out sharp and clear.