Sunday 30 August 2015

Smelly moths & a Woodchat Shrike

Painted Lady, Bovingdon Brickworks

Bovingdon Brickworks (BMT): If the weather thinks that by throwing in a reasonable day of sunshine yesterday, I’ll forget the preceding week of grey skies, showers and low temperatures, it’s sadly mistaken. Last week was one of those unremarkable, uninspiring, plodding sort of weeks. Even netting a Vapourer moth (Orgyia antiqua) near a Brickworks Buddleja didn’t return the spring to my step although reading about this day-flying species afterwards was fascinating. Antennae so sensitive that they can sniff out a female more than a mile away! And, whilst the males are blessed with these extraordinary scent detectors, the females are flightless and basically live to “stink” and reproduce. I’m glad I’m not a Vapourer moth!

A very worn and slightly disabled male Vapourer moth (Orgyia antiqua)
The moth requires both antennae to be in tact in order to determine the direction of scent and to navigate accurately. 
The close up shows the antennae are covered with thousands of tiny hairlike olfactory receptors

I had hoped the Painted Lady passage would continue this week but, if there were any around, they weren’t flying or visible: both are possibilities due to the weather and the inaccessibility of the scrub in their favoured area. In spite of that, most visits have included c5 of each fresh Red Admirals, Peacocks and Speckled Woods, 2-3 fresh Brimstones, 2-3 Small Tortoiseshells & Commas, a fresh Small Copper, a few Common Blues, Whites sp, worn Meadow Browns and Gatekeepers and, on Friday, a very tatty Ringlet.

Still plenty of noisy Chiffchaffs, Willow Warblers and Blackcaps around or passing through, and there are large family parties of Goldfinches throughout the site and smaller groups of Linnets.

On Friday, during a spell of sunshine, one of the Southern Hawker females perched up for a moment.

Yesterday, I escaped the local and got to see a new bird: a Woodchat Shrike. A juvenile turned up on Friday at Blakehill NR, near Cricklade in Wiltshire, and, much to everyone’s relief, had stayed put overnight. The species’ nearest breeding territory is southern Europe, whilst winters are spent in open bush country in Africa, south of the Sahara. This youngster had obviously found itself blown in the wrong direction and will hopefully get back on a northerly, heading south, in good time. Although not quite where it’s supposed to be, it was feeding very well, flying to the ground, catching grasshoppers and other large insects and returning to a perch to devour them. It remained pretty distant (100+ metres away) but that’s what telescopes are for, I guess.

Blakehill NR, location of Woodchat Shrike plus the worst digiscoped photos ever! Heat haze + distance = cr*p photos.
Still, you can just make out the pale rump, pale scapular patch and pale primary panel on the bird.

Sunday 23 August 2015

A Hummer in the Sun

Bovingdon (BMT): Almost 30°C yesterday with blazing sunshine. I got lucky with the/a Hummingbird Hawk-moth briefly coming to the Buddleja at the Brickworks again. Managed to get 6x the shutter speed possible last Thursday, which still isn’t fast enough but about as good as I can get with my equipment. Decided the image worked better with the Hawk-moth “colour popped”. In the afternoon, another (or the same) Hawk-moth was feeding on Buddleja elsewhere on site.

6 Painted Ladies yesterday, all around the same Buddleja and all new except one which had lingered from the previous day.

Friday 21 August 2015

A Hummer & the Ladies

Disappointment awaits those looking for hulking great SUVs draped with scantily clad dames (fortunately...or unfortunately, depending on your perspective). This is strictly Lepidoptera content, starting with the fab little Hummingbird Hawk-moth (Macroglossum stellatarum) that swooped in only seconds after I rocked up at the Buddleja.

Bovingdon (BMT): Thursday was dark and damp and I really didn’t think much would be flying at the Brickworks. But, it never ceases to amaze me just how critical, and yet how seemingly random, timing can be. At the entrance to the site, there’s a large Buddleja bush, and it’s always my first stop. Yesterday, I arrived and almost simultaneously, in came a Hummingbird Hawk-moth, totally transforming the stagnant gloom into vivid, buoyant, frenzied action. Darting, hovering and feeding before finally being chased off by a teeny, weeny fly; I enjoyed every second it was in sight. Had I arrived a minute later, I would have missed it. A few minutes earlier and I might have carried on, ignorant of its approach. I really did feel extremely fortunate to have seen it and although the photographs don’t do it justice (no chance of a fast shutter speed unfortunately), I was chuffed to get them. For more on Hummingbird Hawk-moths, this RSPB article is short but packed with great info.

Earlier in the week, there had been a big influx of passage Willow Warblers and Chiffchaffs and, in the sunshine, Red Admirals, Peacocks, Small Tortoiseshells, Commas, Common Blues, Small and Large Whites, Speckled Woods, a Holly Blue, a Small Copper and a few worn Meadow Browns and Gate Keepers kept me busy. There’s also been a steady passage of the migrant Painted Lady butterflies. Ostensibly, they seem to stay less than 24 hours. The one I found on Monday had gone when I next visited on Wednesday but another was in its place. That too had moved on and was replaced by a further 2 on Thursday. Today, another had arrived but Wednesday’s specimen had returned and one from the previous day had lingered but incurred some damage to the rear of its hindwings. All of this week’s Painted Ladies have turned up in the same small area, rich in flowering Buddleja. This species’ obvious tendency to wander does make me wonder just how many are actually passing through at the times I’m not on site?!

The best way I’ve found of keeping track of butterflies is using photography. No two Painted Ladies are the same, as far as I can work out. Variations in their mottled patterning and/or the presence of wear or damage makes it possible to recognise individuals. I’ve definitely seen at least 9 specimens so far this year at the Brickworks with a 10th likely (on 18th June) and an 11th on another visit when I was looking for something else and didn’t take much notice or photograph it. Below are the 9 certainties and their date stamps (including the 2 repeats from today). Collated like that, they look rather beautiful and I'm glad I've kept a record, although, how long I keep it up remains to be seen!

Tuesday 18 August 2015

Digiscoping: The Ruff Cut

Just a quick post this evening with some photos and video footage of the juvenile Ruff roaming the west quadrant of Wilstone reservoir today. Unfortunately, the Wood Sandpiper, which had been feeding alongside it, had legged it to the far bank of the reservoir moments before I arrived. The distant south quadrant was the Sandpiper Savoy today: 5 Green Sandpipers, 3 Common Sandpipers and the Wood Sandpiper were all resting and refuelling there.

So, I was using the Ruff as digiscoping practice (whilst also admiring its fresh, spangly, juvenile plumage, of course!). It was 60-80 metres away, feeding, preening and at times roosting. Conditions were overcast, grey and cool, with an occasional breeze. The results aren’t too bad considering the lack of light and distance involved. Once again, the white balance is off and I’ve not been able to correct it in post-processing. I need to test out other camera white balance settings and see if I can fix it at source. Photos and video were digiscoped (Swaro ATS80HD, x30W EP, Swaro DCA, Panasonic DMC-G3, 20mm f1.7).

Monday 17 August 2015

Brown Hairstreaks, Silver-spots & migrants

Saturday was a good day. It started with a Wood Sandpiper at Wilstone reservoir, which admittedly, at a distance of c600 metres, was dangerously close to being a featureless bird-blob; and it finished with an infinitely closer, fiery male Redstart, flicking his beautiful red tail, catching insects in the late afternoon light at the horse paddock on Nettleden Road, Water End. In between, there were my first Silver-spotted Skippers at Aston Rowant NNR, followed by my first Brown Hairstreaks at Otmoor RSPB. During a wander around the marshes at Otmoor, a couple of Ross’s Geese, a Marsh Harrier, a pair of Brown Hares, my first Roesel’s Bush-cricket and good numbers of common dragonflies were all enjoying the dry weather after 2 days of rain. A fresh Painted Lady fluttered past and there had obviously been a good second generation of Common Blue butterflies at the reserve. Here are a few photos from the day, starting with the Silver-spotted Skippers.

Mating Silver-spotted Skippers (Hesperia comma), a national rarity, on the wing late June - early Sept

Silver-spotted Skipper. Larval foodplant: Sheep's-fescue (Festuca ovina)

After the sun-loving Skippers (they don't bother flying on overcast days - very sensible!), it was on to Otmoor RSPB for another butterfly rarity, the Brown Hairstreaks (Thecla betulae). We were as jammy as Jammie Dodgers and walked straight up to a chap who was watching 3 of them! Last weekend this same chap had spent more than 3 hours waiting for a sighting without success, a scenario I know all too well.

The views were far better than I had ever hoped for. The icing on the cake would have been a fresh female but I was truly content with the 3 males, one of which was in pristine condition.

Male Brown Hairstreak (Thecla betulae). The UK's largest hairstreak species. Primary foodplant is Blackthorn

Brown Hairstreak, open-winged (male)

Two males. Fresh v Worn

Nothing like standing on your rival's head to get the message across!

A couple of final pictures: a female Southern Hawker dragonfly (Aeshna cyanea) and a female Roesel’s Bush-cricket (Metrioptera roeselii). I’d only ever seen the latter in photographs and didn’t really think my ID was correct. I fired off a burst of 3 shots with a view to checking when I got home. Kicked myself when I realised I was right and really should have made the most of the opportunity. Ah well, another place, another time...I hope. Incidentally, the rather large (and lethal-looking!) sickle-shaped protrusion at the rear of the Bush-cricket is the ovipositor, and the reason I know it's a female...

Friday 14 August 2015

Minty moths, born of fire

Those who pop in here regularly will likely have noticed that I have a soft spot for finding moths during the day time. Doing so always feels a bit like I’ve uncovered a mysterious wormhole in the fabric of the universe because, as everyone knows, moths only exist after dark. Oh ok, they don’t vanish into thin air as the sun comes up, but there is a sense in which discovering their hiding places and roost sites is like pulling back a veil. And, of course, there are the day-flying moths, which are just as exciting to see because they hide in plain sight. Like undercover agents, they live obscured, in the shadows of the big, bright and popular butterfly community. Only the initiated seek them out.

This week, it was the pretty little Mint Moth that caught my imagination. Smaller than my lady-sized thumbnail and, as the common name suggests, the larvae feed on mints and the adults spend most of their time also on/around these herbs. Their other common name, Small Purple and Gold, sums up their main colouring but their scientific name is also worth a closer look. Pyrausta aurata. The “aurata” is fairly straightforward and comes from the latin for “gilded” or “golden” or “overlaid/adorned with gold”, just as the little moth is. “Pyrausta” or “fire-winged”, I think, is a reference to the mythical insect fabled to live in or born from fire. I’m not quite sure how this relates to the moth. Perhaps it is a reference to the rich purple-crimson colouring which is also associated with the fire-born Phoenix, rising from the ashes? I don’t know, but for a little moth it’s got a big name: Fire-born, adorned with gold!

As this moth ages, its vibrant, regal colours fade as the scales wear away. Towards the end of its life, it does look as though it's escaped the flames and has been left brown and singed.

A fairly fresh specimen

Signs of wear starting to show

A very worn specimen!

The above were all found at Roughdown Common, amongst a population of at least 25 moths, making the most of the deliciously scented Wild Marjoram (Origanum vulgare). The species flies by day and night.

Thursday 13 August 2015

Damsels in white tights!

Before I hightailed it up to Warwick last weekend, I joined a friend for a wander along the Aylesbury arm of the Grand Union canal, west of Wilstone Bridge. We were on the hunt for damsels sporting white tights, better known as White-legged Damselflies (Platycnemis pennipes)...obviously. Apart from being “uncommon”, they are also nice and easy to identify. If you find a damselfly with white legs, you’ve found, you guessed it, a White-legged Damselfly. Simples. No other UK species has white legs. If only everything in life were as straightforward!

They prefer slow-flowing streams and rivers and occasionally canals and ponds. Populations are localised, and found only in southern England and a few sites in Wales. Over a stretch of about 1km, we found at least 20 of them, along with what was likely double that number of Blue-tailed Damselflies (Ischnura elegans). I’d hoped to see maybe a handful so 20+ was fantastic.

Broadly speaking, the males are a pale blue. The females a pale creamy white when immature, becoming a pale green later. For more detailed info see here.

I watched this male fly up from his perch, snatch a fly from the air and then settle back to eat it - not something I'd ever seen a damselfly do before.

As a bonus, I found my first Dingy Footman (Eilema griseola), dressed for the part in its elegant greys and beiges.

Tuesday 11 August 2015

Pied Flycatcher at Pitstone Hill

Now there’s a title to reflect a day when creative thinking is quite beyond me. So, yes, a fantastic little immature Pied Flycatcher was spotted on the hills early this morning. This species is a scarce passage migrant and I’ve only ever seen one other (up the road at Weston Turville reservoir in 2013).

I was fortunate to be able to get to Pitstone Hill by about 10:30 this morning. The bird made it easy for me and was sitting out on the limb of a small bush. However, s/he zoomed off quick-smart and it was then another 15-20 minutes before I found it again. This time, far more settled, in a raggedy looking Elder tree. After a while, it became clear the bird was essentially doing a circuit of the scrub surrounding the gully and, if I positioned myself in one spot, it would eventually just come back around again. Perfect!

Between chatting to various other Flycatcher fanciers and waiting for photo opportunities, I ended up hanging around for a couple of hours. In all that time, the bird only once caught something from the air. The rest of the time, s/he was darting to the ground to catch spiders and other ground dwelling invertebrates.

In terms of photography, I was trying to stick to digiscoping (I need the practice!). Apart from the bird’s tendency to move fairly rapidly from perch to perch, conditions were ok: very little wind, just about enough light (some sunshine would have been even better) and the distance to the bird was spot on. The next photograph was digiscoped*. The white balance is slightly off but focus and sharpness aren’t bad. The first and final photographs were taken with the long zoom lens (Panasonic m4/3 100-300mm) and although there are less pixels on the bird, the colours are more accurate.

* Digiscoping set-up: Swarovski ATS80HD scope + Swaro DCA adapter + Panasonic DMC-G3 with 20mm f1.7 lens + remote release.

Sunday 9 August 2015

Butterflies that flutter by

Bovingdon (BMT): It’s always easy, and mildly reassuring, to fall back into old routines after a good break. Having been away in Warwick for a few days, yesterday morning’s sunshine and warmth was perfect for catching up with the local wildlife. At the Brickworks, I came across 3 species of dragonfly, which is pretty good going there (female Southern Hawker, male and female Brown Hawkers and an Emperor). The second generation of Common Blue butterflies have been emerging, all looking pristine and perfect. There were a fair few mating pairs around the site too, making preparations for next season.

The best welcome home present, though, was to find a splendid male Silver-washed Fritillary. It’s only the second one I’ve found at the site (the first was last year, also a male, but he looked more dead than alive, with a greater resemblance to a waffle than a butterfly! Take a look if you don’t believe me, HERE).

There’s an underlying sense of awe whenever I see this species. It’s our largest fritillary and in spite of being Tango orange, it’s the silver streaks and shimmer on the underwing that inspired its name. Its flight appears effortless and buoyant. It looks to be floating on air and, weirdly perhaps, it makes me think of long, luscious eyelashes moving slowly and gracefully. Perhaps it’s the black markings on the upper wing or that we talk about "fluttering eyelashes"... Anyway, it’s not a species you can miss, even across shoulder-high Teasel and Thistle heads.

I had to wait quite some time for him to land within photographic range and fully open his wings. It’s only then that you get a really good look at the 4 distinctive black veins on the forewings, known as “sex brands” (now there’s a blog post title that would generate hits!). These veins contain special “androconial” scales (i.e. sexual scent scales, to those of us who don't speak butterfly) which the males use during courtship.

I’ve had very little experience of this species so I’ve never seen the sex brands and scent scales put into action! However, having read the UK Butterflies description of courtship, I hope very much that one day I will:

“The courtship flight of this butterfly is one of the most spectacular of all the British species. The female flies in a straight line while the male continuously loops under, in front and then over the top of the female. With the courtship flight over, the pair lands on a convenient platform where the male showers the female in scent scales. The male then draws the female's antennae over the sex brand and mating subsequently takes place.”

The morning didn’t end with the Fritillary. There were also a couple of Painted Ladies on site. One, with a malformed or missing right antenna, was nectaring on Thistle and dancing around a pair of mating Common Blues on the open ground; the other, which was looking a little frayed around the edges, was nectaring on Bramble in dense scrub. I think that makes a total of at least 5 possibly 6 Painted Ladies at the site this year, which definitely beats the 1 from last year.

I called in at the Brickworks this morning but no sign of the Fritillary and only one Painted Lady remained. Two Small Copper were a cheery sight even if one of them looked half eaten!

Finally, I checked on the Small Blue colony yesterday, on the A41 Bourne End/Hemel slip road. Still just 3 second generation butterflies....but fab to see!

Sunday 2 August 2015

The Blues on chalk hillsides

The forecast for last Friday morning seemed to suggest wall-to-wall sunshine. It was actually more like wall-to-wall cloud, with the occasional ray of warmth. Plus, a stiff breeze. Hindsight is a wonderful thing. Anyway, the foot of Ivinghoe Beacon, on the west side, was peppered with splashes of sky blue. Delicate, tissue paper thin Harebells matched the males of the Chalkhill Blues fluttering low over the chalk grassland….the very butterflies I was hoping to see and photograph.

Almost immediately after I arrived, I spotted a mating pair. The light was flat and dull and so I decided to sit down beside them and wait for the clouds to pass. I offered them my finger, seeing if they might like to climb on. The promise of warmth was obviously appealing and they settled quickly, finding a position whereby both their bodies were in contact with my skin so as to absorb as much heat as possible. I was glad to be of service!

Nearly half an hour we waited, me and the butterflies, nestled patiently amongst the Harebells. At long last, the sun popped its head out, the temperature rose instantly, the stiff, chilling breeze dropped, and the male opened his wings in welcome. I took a few photos and then returned the pair to the ground, glad to have been an inadvertent part of their courtship.

In the afternoon, I checked out another chalk hillside, the verge of the A41 in Bourne End/Hemel Hempstead, where I’d discovered the Small Blue colony earlier this Spring. I have been visiting regularly over the last few weeks, seeing how the larvae have been developing and wanting to catch the first of the second generation adults, if there were any. I was as pleased as punch to find 3 fresh Small Blues! And, on the westbound slip-road, in one small area, I counted 32 Six-Spot Burnets, including numerous mating pairs, all on Field Scabious! I’ve never seen so many at once.

All in all, a good day with the Blues on chalk hillsides.

Hemel Hempstead Small Blues: from larva to adult