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Small Heath in Dorset: what your tweets tell us ...

Feature 1 - Mon, 20/05/2019 - 21:15
  • A butterfly common on downland and rough grassy places although less common than it once was.

     

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The small heath is certainly a small species and that can help identify it from other browns. The underside of the wing is quite similar to the meadow brown and the gatekeeper so in this case size matters if it is at rest with its wings closed. The small heath has several overlapping broods each summer so the can be seen almost consistently from May right through until October in mainly grassy areas on downs, cliffs and heath. The small heath is probably the most common grassland species over the course of a summer but it may be outnumbered by Meadow Brown in mid-summer.

Here in Dorset they start to emerge in week 18 which is around the second week in May. There is one report from week 16 in late April for 2017. There are then reports in most weeks through until week 43 at the end of October but there is a break three week break between broods from week 30 to 32 in July. The number of reports is greater in late summer than earlier in the year and I think that reflects the fact that they do seem to be more numerous later in the season.

The are records of small heath from many sites across the county with the dominant vegetation of those sites being calcareous grassland and also heath.

 

Contributed by: Peter Orchard
Categories: Features Output

Ringlet in Dorset: what your tweets tell us ...

Feature 1 - Sun, 19/05/2019 - 21:32
  • A declining grassland species named for the ring shapes on its wings

     

    Photograph By: Peter Orchard
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It is just my perception, with no data to support it, that the ringlet may be being seen more frequently now than it was, say, thirty years ago. That said the Nature of Dorset database only has twenty records for 2017 and 2018 combined so it is one of the least reported of the more accessible butterflies; by that I mean that some species are hard to find because of their preferred habitat and so have few records. The ringlet is seen mainly in near lush vegetation in damp, shady areas in woodlands, along hedgerows and riverbanks. Being mainly dark brown with just a series of light brown rings on its underwings it cannot really be confused with any other species if seen at rest. 

The reports we have for Dorset from tweeted sightings show emergence of the single brood in week 25 and ends in week 28; just a four week flight period around the latter part of June and in to early July. The textbooks agree on mid-June for first sightings but consider ringlets likely to be seen in to mid-August. May be as more data is accumulated the position with the ringlet here in Dorset will become clearer.

We have records from fifty-three different sites in Dorset with broadleaf woodland being the dominant habitat type across these sites, however grassland and heath also feature. That said, many of the sites with grassland or heath are also part woodland so I think we can consider this butterfly a woodland species. The distribution map shows sightings scattered across the county with no real concentration in any particular area and it is something of a scarcity on the Purbeck and Poole heathlands. 

 

Contributed by: Peter Orchard
Categories: Features Output

Meadow Brown in Dorset: what your tweets tell us ...

Feature 1 - Sat, 18/05/2019 - 21:20
  • A very common butterfly of grassland and waste places.

     

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I do not have access to any figures from surveys but I suspect that the meadow brown is the most numerous and possibly most widespread butterfly in Dorset. They lay their eggs on various species of frequently found grasses and so where you find those grasses you will possibly find meadow browns and that is just about everywhere! It is very common on limestone and chalk grassland and we have quite a lot of that in Dorset but the meadow brown can also be found along woodland rides, on coastal dunes, by hedgerows and on road verges (unless they are the ones cut every other week by the Council) and areas of 'wasteland'. They are not that common in gardens though thanks to our lawn mowers and our desire to keep our grass cut short, assuming there is grass in the first place given the current trend to decking and paving.

The database reports show the meadow brown taking flight in week 21 in late May but June produces the most reports. From then on reports are lower in numbers but continue right through until week 43 in late October. My textbooks quote late May to late October as the flying period so it seems Dorset conforms to the national norm. 

There are reports from almost a hundred locations across Dorset which does indicate how widespread they are. The most frequent habitat types occurring on those sites are grassland followed by woodland and heath. The distribution map confirms the density of records but there are a few gaps mainly it seems around the agricultural belt south of Cranborne Chase but that may be due to lack of recording rather than lack of meadow browns.

 

Contributed by: Peter Orchard
Categories: Features Output

Gatekeeper in Dorset: what your tweets tell us ...

Feature 1 - Fri, 17/05/2019 - 21:08
  • A delightful and quite common little brown and orange butterfly often found near or on brambles.

     

    Photograph By: Peter Orchard
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I always new this delightful little butterfly as the hedge brown; it is a member of the 'brown' family and is often found along hedgerows, especially hedges with brambles present. With name standardisation it is now known as the gatekeeper and I think that is a much more interesting name than the rather dull hedge brown. The gatekeeper is found in a wide range of habitat, not just hedgerows. You will find it along sunny woodland rides, in parks and gardens, on sea cliffs, scrubby grasslands and even heath. Whist they adore bramble they are happy on almost any nectar bearing flower including thistles and ragwort and in our garden they have a particular passion for marjoram.

The reports we have in the Nature of Dorset database show the gatekeeper emerging in week 26, reports peak in week 27 and then continue every week until week 32 and then that is it for another year. This means they can be seen in Dorset from late June until late August which ties in exactly with the textbooks.

The gatekeeper is widespread and common here in Dorset and has been recorded at nearly 100 locations and, as the distribution map shows, there is hardly an area of Dorset where they will not be seen. Where there are gaps I suspect this is due to lack of recording rather than the lack of gatekeepers.

 

 

Contributed by: Peter Orchard
Categories: Features Output

Grayling in Dorset: what your tweets tell us ...

Feature 1 - Wed, 15/05/2019 - 19:09
  • A quite common species on the Dorset heaths but far less so elsewhere

     

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The grayling is considered to be a mainly coastal species favouring a variety of open habitat types from heath to limestone grassland. It does not seem to be a woodland species as it likes to sunbathe on dry, bare soil or rock and as such it can also be found in disused quarries and we have few of those here on the Dorset coast. It rarely rests with its wings open and when the wings are closed it can be incredibly well camouflaged and hard to spot; the first you see of it is when it suddenly taking flight as you pass close by its resting place. It also has the amazing ability to tilt to one side to reduce its shadow on the ground! 

The Textbooks indicate that the grayling flies in July and August. Here in Dorset it seems to emerge in week 25 towards the end on June and then there are reports every week through until week 35 which is the first week in September. The most reports come in week 29 and July certainly seems the prime month for them. There is one record in the Nature of Dorset database for week 41 in late October which is certainly a late record and well separated from the main stream of reports.

Forty two locations have recorded grayling in Dorset with Tout Quarry on Portland seemingly a hot spot for them; Tout is a disused limestone quarry which ticks most of the boxes for the grayling's preferred habitat. The distribution map, though, clearly shows that outside of Portland it is the heathland around the Poole basin where grayling are most likely to be seen.

 

Contributed by: Peter Orchard
Categories: Features Output

Marbled White in Dorset: what your tweets tell us ...

Feature 1 - Tue, 14/05/2019 - 21:33
  • A frequent butterfly of chalk or limestone grass downlands and quite common in Dorset.

     

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The marbled white is a brown; that is to say that it is a member of the family Nymphalidae to which many of our brown coloured butterflies belong. To look at, of course, it bears little resemblance colourwise to its cousins being very definitely an attractive patchwork of black and white. This pattern marks them out from all other British species and they should not be confused with anything else. This is a butterfly of flower rich downland and grassy places and thrives in dry, hot conditions. They seem to have a particular liking for purple/mauve flowers and adore knapweeds and thistles and so chalk or limestone grassland is particularly suitable for them but they do also occur in woodlands, along railway lines and even roadsides and hedgerows. Where they do occur their population can often far outnumber other species.

The marbled white is single brooded and flies from mid-June to mid-August. Our Dorset records suggest emergence here is in week 24, right in the middle of June, just as the textbooks say, and reports are continuous through until week 30 at the end of July. After a gap in weeks 31 to 33 there are then two reports in week 34 and week 35, mid August. Strangely, we have one report from week 45 in November 2017! 

There are records from 61 sites across Dorset with Durlston, Lulworth and Badbury Rings seemingly good places to see them. The distribution map, though, puts this in to context showing a definite preference in Dorset for the limestone of the Purbeck coast and Portland and the central chalk ridge that runs from south west to north east Dorset. It is not exclusive to calcareous soils but almost all sites on this geological foundation do seem to have colonies of them.

 

Contributed by: Peter Orchard
Categories: Features Output

Wall in Dorset: what your tweets tell us ...

Feature 1 - Sat, 11/05/2019 - 19:05
  • A once common but now quite scarce species that is still found along the Dorset coast.

     

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I always knew this butterfly as the wall brown but now it is just called the wall which is, in my view, a rather odd name! They certainly likes stone walls and can be seen sunning themselves and absorbing heat from the stones on days when it's not so warm. Its first love is an area of bare, sun-baked earth to rest on. The wall has declined considerably in central and southern England in recent years but here in Dorset we are treated to them along the coastal cliffs where conditions obviously still suit them.

There are thirty six reports of wall in the Nature of Dorset database, interestingly just nine for 2017 but a big increase in 2018 to 27. That could mean population levels vary each year or it could just be down to reporting variations; this may become clearer over time. The reports come in two batches; from week 15 in the later part of April to week 22 towards the end of May. The second brood then emerge week 28 in mid-July and then reports flow continuously through until week 43 at the end of October. October 2018 produced the most reports of any month over the two years we have been collecting data. This pattern of adult visibility ties in with the textbooks.

There are records from thirty five locations in Dorset and the distribution map clearly shows the affinity for coastal sites with just five being inland but even then they are not that far from the coast. The Purbeck coast and Portland are undoubtedly the best place for them here.

 

Contributed by: Peter Orchard
Categories: Features Output

Speckled Wood in Dorset: what your tweets tell us ...

Feature 1 - Fri, 10/05/2019 - 19:17
  • A common butterfly of woodland rides and shady paths.

     

    Photograph By: Peter Orchard
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There are always winners and losers I suppose. Several butterfly species have declined with the demise of coppicing but it is thought this may have actually benefited the speckled wood. The speckled wood is a woodland species first and foremost and is quite happy in shade where most other butterflies prefer not to venture for too long. As a result of this shade tolerance they have done well in overgrown coppices; this has led them to spread out along hedgerows and even into gardens and parks. I was also surprised to learn that they do better in cooler, wetter summers and the recent generally poor years for many butterflies may well have benefited the speckled wood. It is now certainly one of our most common species in Dorset although many people may have never heard of it!

The speckled wood can have up to three overlapping broods a year and so can be seen almost continuously from late March to early November. The Nature of Dorset database has fifty nine records for 2017 and 2018 combined and these show a general emergence from week 12 onwards which is late March. There is a peak in week 16 at the end of April before the reports level out and continue right through until week 45 at the end of October. Whether that peak in week 16 means this is a time when there are most speckled woods about or whether it means that people are reporting their first of the year and then not reporting them thereafter as they are common I am not sure but I suspect it is the latter of the two scenarios.

There are reports from a large number of sites across the county and the distribution map shows just how widespread they are. The gaps across the centre of the county will be partly down to lack of observer coverage but could also reflect the lack of woodland across the chalk spine of the county.

 

Contributed by: Peter Orchard
Categories: Features Output

Marsh Fritillary in Dorset: what your tweets tell us ...

Feature 1 - Thu, 09/05/2019 - 21:19
  • A nationally scare species; it likes damp, grassy downland sites so long as its food plant, devils-bit scabious occurs. On the wing in late May and throughout June

     

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The marsh fritillary is yet another butterfly that is absent from much of Britain but that can be found in a number of places in Dorset. It is certainly not common here, nor is it anywhere, but careful habitat management means its seems to be holding its own and not suffering the declines of elsewhere in the country. Marsh fritillary is a bit of an odd name for this butterfly; it has the chequered wing patterns that fritillaries have but it is not found in marshes. It does like damp, flower rich meadows where devil's-bit scabious grows but it also can be found on dry downland slopes that are far from being 'marshy'. 

The marsh fritillary is single brooded and the books say it emerges in Mid-May and can be seen until mid-July. The records we have so far in the Nature of Dorset database would indicate a much shorter season starting in week 19 which is mid-May but there are no reports after week 23 in mid-June. The most prolific weeks are 21 and 22 at the end of May and beginning of June.

There are records from fourteen locations in Dorset which are split roughly equally between damp grasslands sites and chalk downland. Alners Gorse, Giant Hill and Powerstock Common all hold reasonably sized colonies and a visit at the right time of year to any one of these should give you a chance to see them.

 

Contributed by: Peter Orchard
Categories: Features Output

Silver-washed Fritillary in Dorset: what your tweets tell us ...

Feature 1 - Wed, 08/05/2019 - 21:30
  • A large butterfly with intricate markings. Essentially a butterfly of woodlands, especially areas of well established woodland, both deciduous and coniferous.

     

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When seen in a woodland setting the silver-washed fritillary is unmistakable as it is a large, bright orange butterfly that cannot really be confused with any other species found in this habitat. This is true in Dorset I believe as the pearl-bordered fritillary is no longer found in Dorset woodlands having faded out here some years ago. The pearl-bordered may have been subject to a sad demise but thankfully the silver-washed is doing alright and is certainly holding its own for the time being at least. It should be born in mind that there is a darker form of silver-washed, the valezina form, which can be encountered and at first sight looks a totally different species! 

The thirty eight reports of silver-washed fritillary in the Nature of Dorset database for 2017 and 2018 combined show that the first of these butterflies can be seen in week 25 in mid-June and then they are reported every week for seven weeks until week 31 in early August; they seem to be at their peak in early July. This flight period ties in with textbook information which validates the records we have here from Dorset so far.

There are records from thirty nine sites and they are all predominantly, or at least partially, broadleaf woodland where these butterflies feed in sunny glades on the flowers of bramble.

 

Contributed by: Peter Orchard
Categories: Features Output

Dark Green Fritillary in Dorset: what your tweets tell us ...

Feature 2 - Tue, 07/05/2019 - 21:09
  • A large orange and brown butterfly of open grassland and downs. The underside of the wing is partly dark green.

     

     

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The dark green fritillary is not green, it is orange and brown like many of the other fritillary butterflies. The name is not a total falsehood though as if you look closely at one whilst nectaring with its wings closed you will see the underside of the wing is partially green; whether that is dark green is open to debate! In flight it may seem, at first, difficult to tell the dark green fritillary from the superficially similar silver-washed fritillary. However there two fundamental differences with nothing to do with colouration that will help point you in the right direction. Firstly, the dark green is a butterfly that is rarely seen away from flower-rich chalk or limestone grassland whereas the silver-washed is much more of a woodland species. Secondly, the dark green is a powerful; flyer and flies with a flap. flap. glide, flap, flap, glide ... I do not think I have ever seen that in any other butterfly.

Sadly, there are only eleven reports of dark green fritillary in the Nature of Dorset database for 2017 and 2018 combined which is not a lot to work with however it does show that the this species emerges around week 22 in mid June and can be seen until week week 30, possibly on to week 32, in mid of August, that seem to tie in with what the textbooks indicate.

There are records from thirteen sites in Dorset and every one is fundamentally calcareous grassland; various points along the Purbeck coast seems to be the best places to see them but they are not particularly common anywhere. I find it surpring that there are no reports from Portland as yet.

 

Contributed by: Peter Orchard
Categories: Features Output

Dark Green Fritillary in Dorset: what your tweets tell us ...

Feature 1 - Tue, 07/05/2019 - 21:09
  • A large orange and brown butterfly of open grassland and downs. The underside of the wing is partly dark green.

     

     

    Photograph By:
Click/tap the photo for the full details of this species

The dark green fritillary is not green, it is orange and brown like many of the other fritillary butterflies. The name is not a total falsehood though as if you look closely at one whilst nectaring with its wings closed you will see the underside of the wing is partially green; whether that is dark green is open to debate! In flight it may seem, at first, difficult to tell the dark green fritillary from the superficially similar silver-washed fritillary. However there two fundamental differences with nothing to do with colouration that will help point you in the right direction. Firstly, the dark green is a butterfly that is rarely seen away from flower-rich chalk or limestone grassland whereas the silver-washed is much more of a woodland species. Secondly, the dark green is a powerful; flyer and flies with a flap. flap. glide, flap, flap, glide ... I do not think I have ever seen that in any other butterfly.

Sadly, there are only eleven reports of dark green fritillary in the Nature of Dorset database for 2017 and 2018 combined which is not a lot to work with however it does show that the this species emerges around week 22 in mid June and can be seen until week week 30, possibly on to week 32, in mid of August, that seem to tie in with what the textbooks indicate.

There are records from thirteen sites in Dorset and every one is fundamentally calcareous grassland; various points along the Purbeck coast seems to be the best places to see them but they are not particularly common anywhere. I find it surpring that there are no reports from Portland as yet.

 

Contributed by: Peter Orchard
Categories: Features Output

Comma in Dorset: what your tweets tell us ...

Feature 2 - Mon, 06/05/2019 - 21:21
  • A frequently encountered brightly coloured butterfly that favours open areas as well as woodland edges. 

     

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With its rather irregular, almost ragged, wing edges the comma is unique in appearance and familiar to many as they freely venture into shrubby parks and gardens although their main habitat is broadleaf woodland where they can be seen patrolling woodland rides and glades. The males are somewhat territorial and will attack any other male coming within their chosen patch; females however are made very welcome! Like others in the same family they hibernate over winter but will readily emerge on warmer winter days to feed and so may be seen at almost anytime of year apart from a break in June between first and second broods. Nettles form the food plant of the larvae and the second brood adults are very often seen around brambles and enjoy blackberries.

Apart from one report in week 8 in February and one in week 43 in October the records in the Nature of Dorset tweets database show emergence of the comma from hibernation in week 11 towards the end of March and then reports have come weekly through until week 18 at the later end of May. The inter-brood break seems to last until week 24 in late June and then the reports again regular until  week 33 at the end of August. Interestingly there is then another break until a further flurry of activity from week 37 to week 39 in September so that may be evidence of a third brood here in the south?

There are reports of comma butterflies from seventy three sites in Dorset and the list is made up primarily of woodland and scrubby sites but heathland and coastal habitats also feature which shows how diverse and widespread they can be.

 

Contributed by: Peter Orchard
Categories: Features Output

Comma in Dorset: what your tweets tell us ...

Feature 1 - Mon, 06/05/2019 - 21:21
  • A frequently encountered brightly coloured butterfly that favours open areas as well as woodland edges. 

     

    Photograph By:
Click/tap the photo for the full details of this species

With its rather irregular, almost ragged, wing edges the comma is unique in appearance and familiar to many as they freely venture into shrubby parks and gardens although their main habitat is broadleaf woodland where they can be seen patrolling woodland rides and glades. The males are somewhat territorial and will attack any other male coming within their chosen patch; females however are made very welcome! Like others in the same family they hibernate over winter but will readily emerge on warmer winter days to feed and so may be seen at almost anytime of year apart from a break in June between first and second broods. Nettles form the food plant of the larvae and the second brood adults are very often seen around brambles and enjoy blackberries.

Apart from one report in week 8 in February and one in week 43 in October the records in the Nature of Dorset tweets database show emergence of the comma from hibernation in week 11 towards the end of March and then reports have come weekly through until week 18 at the later end of May. The inter-brood break seems to last until week 24 in late June and then the reports again regular until  week 33 at the end of August. Interestingly there is then another break until a further flurry of activity from week 37 to week 39 in September so that may be evidence of a third brood here in the south?

There are reports of comma butterflies from seventy three sites in Dorset and the list is made up primarily of woodland and scrubby sites but heathland and coastal habitats also feature which shows how diverse and widespread they can be.

 

Contributed by: Peter Orchard
Categories: Features Output

Peacock in Dorset: what your tweets tell us ...

Feature 2 - Sun, 05/05/2019 - 19:23
  • A very common butterfly in Dorset and seen in grassy habitats including gardens, hedgerows, woodland rides and glades, as well as chalk downlands and cliffs.

     

     

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With its distinctive wing colouration and 'eye' markings, as well as being a regular visitor to gardens, the peacock must surely be one of our best known butterflies. It is a resident breeding species in Britain laying eggs on common nettle and its black, spikey caterpillars are a common site munching their way through nettle leaves totally immune to any stinging that we suffer if we touch them. It is not just a garden butterfly of course, it can be encountered almost anywhere there are nectar rich flowers to feed on and that includes woodlands, scrub, heath and grassland. This is a hibernating species and so it can potentially be seen at almost anytime of year with a break around June between broods.

The weekly reports chart shows sightings from week 6 in February continuously through until week 18 in late May. Then follows the inter-brood wait with virtually no reports until week 24 in early July. Then follows continuous reports until week week 32 at the end of August. Reports then become a little more sporadic, but still frequent, until week 44 at the end of October. Odd reports can then be seen in the winter months when they emerge from their hibernation on warmer, sunny days in November, December and January.

There are reports from many sites across the county showing just how diverse it is in its choice of habitat.

 

Contributed by: Peter Orchard
Categories: Features Output

Peacock in Dorset: what your tweets tell us ...

Feature 1 - Sun, 05/05/2019 - 19:23
  • A very common butterfly in Dorset and seen in grassy habitats including gardens, hedgerows, woodland rides and glades, as well as chalk downlands and cliffs.

     

     

    Photograph By:
Click/tap the photo for the full details of this species

With its distinctive wing colouration and 'eye' markings, as well as being a regular visitor to gardens, the peacock must surely be one of our best known butterflies. It is a resident breeding species in Britain laying eggs on common nettle and its black, spikey caterpillars are a common site munching their way through nettle leaves totally immune to any stinging that we suffer if we touch them. It is not just a garden butterfly of course, it can be encountered almost anywhere there are nectar rich flowers to feed on and that includes woodlands, scrub, heath and grassland. This is a hibernating species and so it can potentially be seen at almost anytime of year with a break around June between broods.

The weekly reports chart shows sightings from week 6 in February continuously through until week 18 in late May. Then follows the inter-brood wait with virtually no reports until week 24 in early July. Then follows continuous reports until week week 32 at the end of August. Reports then become a little more sporadic, but still frequent, until week 44 at the end of October. Odd reports can then be seen in the winter months when they emerge from their hibernation on warmer, sunny days in November, December and January.

There are reports from many sites across the county showing just how diverse it is in its choice of habitat.

 

Contributed by: Peter Orchard
Categories: Features Output

Small Tortoiseshell in Dorset: what your tweets tell us ...

Feature 2 - Sat, 04/05/2019 - 19:06
  • A familiar butterfly species but with very variable population levels year on year

     

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The small tortoiseshell is another butterfly species whose fortunes are closely linked to those of its nemesis, in this case a parasitic fly Sturmia bella. In good population years for the butterfly the parasitic fly has ample caterpillars to lay its eggs in to and so the fly prospers at the expense of the butterfly and so numbers of the small tortoiseshell fall meaning less caterpillars for Sturmia bella and so its population level falls allowing more butterflies to emerge and so it goes on. That said, the population of small tortoiseshells seems to have fallen in recent years and it is far less common than it once was; well that is so in our garden anyway and this is a butterfly very much at home in gardens where it is quite comfortable feeding on various cultivated varieties of daisies and other flowers.

As a butterfly that hibernates they can be seen at almost anytime of the year as they will emerge on milder days in winter. Full emergence tends to come in late March and early April and then during May there is a hiatus whilst the second brood is awaited and they are then seen from June onwards. The weekly sightings in the Nature of Dorset database show this very well. There are a few reports from week 8 at the end of February until week 11 and then there is a surge of reports in week 12 at the end on March through until week 16 at the end of April. Following this there is a gap of seven weeks and then reports start flowing again from week 24 at the end of June on into the autumn. There are then odd reports during the late autumn and winter months.

A good number of sites have reports of small tortoiseshell but interestingly in most cases just the one record. Only Portland and Radipole in Weymouth stand out with four reports and Lyme Regis and the wider Weymouth area three each. 

 

Contributed by: Peter Orchard
Categories: Features Output

Small Tortoiseshell in Dorset: what your tweets tell us ...

Feature 1 - Sat, 04/05/2019 - 19:06
  • A familiar butterfly species but with very variable population levels year on year

     

    Photograph By:
Click/tap the photo for the full details of this species

The small tortoiseshell is another butterfly species whose fortunes are closely linked to those of its nemesis, in this case a parasitic fly Sturmia bella. In good population years for the butterfly the parasitic fly has ample caterpillars to lay its eggs in to and so the fly prospers at the expense of the butterfly and so numbers of the small tortoiseshell fall meaning less caterpillars for Sturmia bella and so its population level falls allowing more butterflies to emerge and so it goes on. That said, the population of small tortoiseshells seems to have fallen in recent years and it is far less common than it once was; well that is so in our garden anyway and this is a butterfly very much at home in gardens where it is quite comfortable feeding on various cultivated varieties of daisies and other flowers.

As a butterfly that hibernates they can be seen at almost anytime of the year as they will emerge on milder days in winter. Full emergence tends to come in late March and early April and then during May there is a hiatus whilst the second brood is awaited and they are then seen from June onwards. The weekly sightings in the Nature of Dorset database show this very well. There are a few reports from week 8 at the end of February until week 11 and then there is a surge of reports in week 12 at the end on March through until week 16 at the end of April. Following this there is a gap of seven weeks and then reports start flowing again from week 24 at the end of June on into the autumn. There are then odd reports during the late autumn and winter months.

A good number of sites have reports of small tortoiseshell but interestingly in most cases just the one record. Only Portland and Radipole in Weymouth stand out with four reports and Lyme Regis and the wider Weymouth area three each. 

 

Contributed by: Peter Orchard
Categories: Features Output

Painted Lady in Dorset: what your tweets tell us ...

Feature 2 - Fri, 03/05/2019 - 21:21
  • An immigrant species to this country from north Africa. In some years we get huge quantities of them and then we can go several years with relatively few. 

     

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The painted lady is a close relative of the red admiral appearing to have similar wing markings with the main difference being the painted lady is much paler, more orange than red. Closer inspection shows the two species to be quite distinct from each other despite initial thoughts of similarity. Like the red admiral the painted lady is a migrant species here in Britain and people seem much more aware about the migration of the painted lady than they do about the red admiral. The painted lady is much more varied in terms of numbers arriving and times of arrival compared to the red admiral. In some years there are very few painted ladies and in others the numbers can be almost overwhelming! There is also a tendency for the first painted lady influx to arrive later in the year than the red admiral; that said, no two years are the same when it comes to the painted lady. The first arrivals often land in July and then they can be seen right through until October or even November. The numbers are swollen by insects hatching from eggs laid by earlier arrivals. Winter survival rates are generally low.

The weekly sightings chart shows that some degree of successful hibernation and winter survival certainly happens with records in January, February and March. Weeks 21 to 25 in May seem to produce a number of reports then there are lesser numbers until weeks 30 to 35 in late July and August. Reports continue through until week 46 in mid November; there were two reports in November 2017 but none in November 2018 so clearly this is weather dependent.

There are records from forty five sites so far and these are mostly coastal locations which reflects the inward migration and butterflies stopping off here to feed. There is a also tendency for these sites to be chalk or limestone and this will probably be because these habitats are rich in wild flowers for the butterflies to nectar on. Painted ladies are often seen in gardens too, especially those with buddleia bushes. 

 

 

Contributed by: Peter Orchard
Categories: Features Output

Red Admiral in Dorset: what your tweets tell us ...

Feature 2 - Thu, 02/05/2019 - 21:21
  • A familiar garden butterfly, especially later in the year.

     

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The red admiral must be one of the most instantly recognisable of British butterflies; it is a familiar sight in gardens, parks and open countryside. It is so familiar that one would think this was a resident species but it is not, it is a migrant arriving in May and June having travelled from north Africa. These early arrivals lay eggs once they arrive and these hatch in to adults later in the summer but numbers are also continually boosted by new arrivals, especially in late summer, and it is from late August through until October that they seem to be most numerous. There is some evidence to suggest that some return back across the channel to mainland Europe as the autumn turns to winter, other succumb to the severe winter conditions and some find sheltered places to hibernate. These hibernating insects will often awake on warmer days in winter and that accounts for why you can actually see them in even January and February.

The red admiral is one of the most regularly reported butterflies in the Nature of Dorset database with ninety five reports in 2017 and 2018 combined. What is remarkable perhaps is that there are records every month from February 2017 through until December 2018 without a break. This demonstrates that some successfully over winter here on the south coast especially as the last two winters have been relatively mild. For much of the year there are just odd reports in most weeks but in September and October the number of reports surges to reflect the combination of more incoming migrants as well as emerging new adults from the eggs laid by the early arrivals.

You can encounter red admiral just about anywhere in Dorset with nearly 120 sites reporting them but if you look at the sites where the most are recorded you will see they are all coastal which shows they are most frequently seen arriving or preparing to leave, often in autumn.

 

Contributed by: Peter Orchard
Categories: Features Output

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