Friday 21 July 2017

Great Scott!

I will be heading to the Isles of Scilly in a few weekends time for some pelagic trips to watch and photograph seabirds. Great Shearwater is always a target on these trips - a long distance wanderer which breeds on islands in the South Atlantic, migrates up the eastern side of South and North America and crosses the Atlantic to pass through our waters, typically in August, before heading south again. As such, I didn't expect to be watching one after work this evening in Weymouth Bay.

I had just arrived home when news broke that a Great Shear was lingering in the Bay. A quick change and I was heading west in the foulest weather we have seen in Dorset for a while. An update from Brett Spencer confirmed that the bird was still present, sitting on the sea, and within half an hour I was watching it, visible intermittently as it crested the waves in a churning bay, through which an Arctic Skua also passed.

At one point a gull mobbed the Shearwater, causing it to make a short flight during which a couple of record shots were possible - I would have left my camera in its bag but for a kindly birder who opened up the back of his camper van to give us some shelter from the torrential rain. A great way to start the weekend and a Dorset tick for most of those who made the effort to see it tonight. See here for some better pictures of this remarkable species.
Not a sight you expect to see in Weymouth Bay in July - either the bird or the autumnal waves
The dark capped appearance and white horseshoe at the base of the tail help identify Great Shearwater
A better view of the white collar giving the dark capped appearance
A rear view showing the white patch at the base of the tail

Sunday 16 July 2017

Purple reign

Yes I realise the terrible pun in the headline would be more fitting for the Purple Emperor than the humble Purple Hairstreak - but I haven't had the opportunity to look for the former so far this summer, whereas a spare Sunday morning a few weekends ago provided just enough time to look for the latter at Butterfly Conservation's superb reserve at Alners Gorse. Like the majestic Emperor, the Purple Hairstreak reveals its colourful sheen when light refracts from the wings at certain angles. I had never really managed to photograph this feature well so that was one objective of the visit. It was easily achieved as tens of this characterful insect were seen, many down at eye level in the relative cool of the morning. As usual my time was a bit limited but a White-letter Hairstreak feeding low down on brambles as I made to leave was a huge bonus.
Male Purple Hairstreak at Alners Gorse
This is the same individual at a slightly different angle - note how the extent of the purple varies with the angle of the light
Another angle on the same individual
Another male complete with short tails
All the Purple Hairstreaks I saw with wings open appeared to be males
Purple Hairstreak underwing shows an eye-spot near the short tail
Buds of Buckthorn appeared as cat-nip to the Purple Hairstreaks
They were present on one small tree in double figures
An attractive species - compare to....
...White-letter Hairstreak, which never sits with the wings open
Comma also on the wing at Alners Gorse...
...and plenty of Ringlet
A fresh Southern Hawker also present...
...and one of our most impressive British species, the Silver-washed Fritillary
A pristine male Silver-washed Fritillary
A slightly worn female Silver-washed Fritillary...
...and here a mating pair
Purple Hairstreak at Alners Gorse - a superb reserve, hats off to BC for making it so

Saturday 15 July 2017

Get counting

Yesterday's launch of the 2017 Big Butterfly Count reminded me that it has been a colourful summer so far for lepidoptera, including a number of subjects I haven't got round to posting about yet. Many butterfly species seem to be having a good year - the count will help establish whether or not that is true - and I have caught up with some spectacular ones around Dorset and beyond over recent weeks.

After a business trip to Cardiff at the end of June I was travelling back through Somerset and despite the lateness of the hour, the temperature was sufficiently high to make it worth dropping in to Collard Hill, site of a successful Large Blue re-introduction scheme, to see if they were still on the wing. The sky had clouded over by the time I arrived but with a little patience I found one or two of these striking butterflies roosting in the long grass of the down. One opened its wings just enough to get a half-decent photograph of the exquisite finger-print pattern on the forewing.
Large Blue
A close-up of a roosting Large Blue...
... and the same individual from a wider angle
A conservation success story, the Large Blue is now established at a number of sites in the south west
Marbled White was also on the wing at Collard Hill
Back in Dorset, a visit to Brownsea provided me with an opportunity to catch up with the White Admiral, one of our most impressive species. It's so many years since I saw them there that I had almost forgotten White Admirals could be found on the island, but I was reminded when another visitor in the bird hide asked if he might have seen one near the start of the track to the hide. Sure enough, on returning there two or three individuals were still coming to the same flowering shrub to nectar.
White Admiral
The White Admiral is a shade tolerant species
The White Admiral posed above me for an underwing photo
The underwing must be one of the most attractive of the British butterfly species... the underwing catches the light to reveal its bright rust colouration
Silver-studded Blues were also out in Dorset early this year and I photographed several in Wareham Forest and around Morden Bog in mid-June. These diminutive blues have declined historically in parallel with the loss of the lowland heath habitat they prefer, but they can still be found in good numbers on the Dorset heaths.
Female Silver-studded at Morden Bog
The silver studs were particularly prominent on this female...
...but more under-stated in this male
Upperwing of a male Silver-studded Blue
These males seemed to have each other in a head-lock
Much rarer than the Silver-studded Blue in a Dorset context is the Small Pearl-bordered Fritillary - I called in at its last remaining site in Purbeck on the way back from Brownsea one afternoon and was pleased to find a few among the grass and gorse in a short visit. Hopefully the Purbeck colony will have a good year. Another brief visit last week to Durlston Country Park produced good numbers of Lulworth Skipper, only found in the UK along the stretch of coast between Swanage and Portland. Another local speciality which we must hope benefits from seemingly benign weather for butterflies this summer.
Small Pearl-bordered Fritillary
Small Pearl-bordered Fritillary underwing
Large Skipper was also at the Fritillary site - compare with...
...the Lulworth Skipper, photographed at Durlston
These Marbled Whites were engaged in synchronised nectaring at Durlston

Monday 10 July 2017

Scarlet fever at Longham Lakes

On Saturday evening Dorset birder Martin Wood posted on Twitter a photograph, taken at Longham Lakes, of a startlingly bright red dragonfly, along with a request for help with the ID. Martin is a popular figure on the Dorset birding scene, not least due to his endearing habit of not checking what the auto-correct function has done to his posts before he sends them. Thus, a number of new species have been added to the Dorset list over the years thanks to these typos, including Montagu's Barrier, Woodstock, Wedge Warbler and the aptly-named Wood Sandpaper.
Scarlet Darter (confusingly also known as Scarlet Dragonfly or Broad Scarlet) is an incredibly vivid shade of red - here resting with wings swept characteristically forward 
The abdomen is flattened compared to other red Darters, and it has a small yellow patch at the base of the hindwing. Note also the blue underside to the eyes, a feature evidently shared with Red-veined Darter
A different angle to show the brilliant scarlet head and eyes. On one of the finer points of ID, 10 or 11 ante-nodal cross-veins on the leading edge of the forewing can be seen on the photos above (compared to 8 in other red darters)
Red-veined Darter had been reported at Longham in recent days and Martin posed the not unreasonable question of whether this might be one of that species. The internet 're-identified from photos' phenomena reared its head at this point with dragonfly buffs confidently proclaiming it to be a Scarlet Darter Crocothemis erythraea - only the 8th record for Britain and apparently the first for Dorset. I had trudged around Longham Lakes in the heat of Saturday afternoon trying to improve on my earlier photographs of Lesser Emperor - unsuccessfully I should add - and was unaware of the presence of the even rarer visitor which must have been present at the same time. So with a good forecast on Sunday morning I made the short journey back to Longham while the rest of the family were having a lie-in, arriving just after 0900.
Lesser Emperor at Longham Lakes - note the pale blue band at the base of the abdomen. An absolute swine to photograph - they seemed to patrol over a much larger area than Emperors, and they hovered only rarely
I never saw one perch in almost 6 hours at Longham - as a result I had to wait patiently in the baking sun and hope for one to pause long enough for the auto-focus to lock on
Fortunately this one did and although the light was unkind I was pleased to have improved on my earlier efforts
Checking the areas of the lakes allegedly favoured by the Lesser Emperors (again, unsuccessfully), after about an hour I headed down to the bottom end of the south lake where Martin had photographed the Scarlet Darter. There I met up with some other local dragonfly hunters who had come to search for the Darter. We spread out and covered the area near where Martin had photographed it, before moving on to pay close attention to a small pool at the base of the south lake.
On any other day this Red-veined Darter would have been the star of the show - but yesterday it played 3rd fiddle to the Scarlet Darter and Lesser Emperor
Brown Hawker - the only other dragonfly to be as restless as the Lesser Emperor, I had to settle for a flight shot
This Golden-ringed Dragonfly was more inclined to perch on tall vegetation - though it seemed to want to stay in the shade unfortunately
As I walked slowly along the edge of the pool, primarily looking for Small Red-eyed Damselflies close enough to photograph, I was stopped in my tracks by a tiny telephone box of a dragonfly which I surmised could only be the Scarlet Darter. Hailing the others, we all enjoyed close views as the Darter basked and made occasional hunting sallies before returning to perch on the same stalk of vegetation.
Emperor Dragonflies were sparring with the Lesser Emperors
A female Emperor
Emperor is more inclined to perch on vegetation than Lesser Emperor
After a bit of debate about the ID during which our disbelieving minds were almost in denial of the clear evidence before our eyes, we eventually ruled out Red-veined Darter and put the news out that the Scarlet Darter was still present. A number of locals and a few from further afield managed to get to Longham to see it before it went missing around lunchtime. Thanks to his discovery of the Scarlet Darter, we can now celebrate Martin for yet another addition to the Dorset list! A great find and a just reward for his diligent coverage of the Lakes.
Black-tailed Skimmer was by far the most numerous large dragonfly at Longham Lakes this weekend
Here a female Black-tailed Skimmer captured in flight
Three species of damselfly in this picture - Small Red-Eyed (top left), Blue-tailed (top right) and Common Blue (bottom left)
After success with the Scarlet Darter, everything else then fell into place - the Lesser Emperor(s), previously so elusive, were found faithfully patrolling the same stretch of the south lake shore, a Brown Hawker floated past, a Golden-ringed Dragonfly played hide-and-seek in some brambles with a pair of Banded Demoiselle, and a Red-veined Darter posed for photos. Some 16 species of Odonata were recorded at Longham Lakes this weekend - firmly establishing it as one of the country's leading sites for this fascinating family.
Common Blue Damselfly
The much rarer Small Red-eyed Damselfly
Banded Demoiselle