Monday, 25 May 2015

Toadflax Brocade in Banstead - a short history

It is not all that long ago that the Toadflax Brocade was considered anything but a very local species. First recorded in the UK in 1939 and as breeding in 1952, colonisation then started in earnest. In the mid-1980s, Skinner considered it 'Well established at Dungeness, Kent and found locally along the coast eastwards to Sandwich and westwards towards Angmering, West Sussex'. Even in the 1998 revision of his book he mentions only 11 other records away from this heartland. Graham Collins 'Larger Moths of Surrey' - published in 1997 - can only lay claim to a single Surrey record, from Bookham Common on 7 July 1970. By the turn of this century moths had started to appear further west along the south coast, and since then they have been recorded as far north as Yorkshire. Of more interest than these isolated wanderers has been the colonisation of London and the Home Counties. Which leads me on to Banstead...

It was in the back garden on 17 August 2009 that I came across a striking larva on Purple Toadflax. Even I was able to put a name to this beast, that of Toadflax Brocade. I had, at that point, not seen the adult moth in the garden, so was then on high alert to rectify the situation. If it had bred in the garden then I had certainly missed them! I didn't have too long to wait, as an adult came to the MV trap on 22 May 2010. In 2011-13 I didn't find any larvae although in each of these years one or two adults appeared at light. Last autumn the three clumps of Purple Toadflax in the garden were alive with the colourful caterpillars - 20 on one clump alone. And, for the past three consecutive nights I have recorded adults. They seem to have happily colonised this small part of Surrey.

The food plant of this species is, not surprisingly, Common, Purple and Pale Toadflax. The early colonists most probably had Common as the only plant of choice. Maybe the colonisation of London has been aided by the ubiquitous nature of Purple. It seeds easily and is a common plant of waste ground. This moth is double-brooded, flying in May-June and again in August. If you have yet to see it, check your nearest clump of Purple Toadflax for the larvae this summer - there will be some nearby!

Saturday, 23 May 2015

At last!

It's been some time coming, but at last there was an evening that felt muggy and an MV trap that had plenty buzzing around it. There may not have been hundreds of moths to inspect at dawn, but there was a fair haul including plenty of species new for the year. Here are a couple of the more visual of them:

Argyresthia trifasciata - not recorded in the UK until 1982 but now spreading north and west and becoming well established. To be found happily in gardens where it mines the leaves and shoots of Cypress. The white head separates it from similar species.

Toadflax Brocade - breeds in my garden on Purple Toadflax where the larvae are easily found in the late summer. Once a scarce species of sparse coastal habitats in the south and south-east - now regularly found in London and the Home Counties.

Wednesday, 20 May 2015

DBO moths

The Dungeness Bird Observatory moth trap was not exactly leaping last week, but compared to some of the totals that nearby recorders were obtaining, it wasn't really all that bad. In fact, this particular moth was notable indeed:

DBO's fourth Ni Moth (above) was the star capture on the night of the 10th/11th and was a new species for me. There didn't seem to be much in the way of migrant lepidoptera around, save for a few Painted Ladies and Sean Clancy's monopoly on Bordered Straws! What was common were these:

The variable and ubiquitous Light Feathered Rustic - I have recorded it twice in my Surrey garden, no doubt wanderers from the small populations that are present on the downs. The variation in colouring and marking is most obvious when you are confronted with a DBO trap full of them.

Tuesday, 19 May 2015

WWBTs and Hobbys

At Dungeness last Thursday the wind swung easterly and the rain set in. The local birders predicted a good bird and they were right - well, almost right, as none of them had actually predicted that there would be TWO good birds. The RSPB reserve was the chosen stop off point for these two White-winged Black Terns (above) and it was Martin Casemore (click here for proper images) who got the prize as their discoverer. As it turned out, none of us needed to run for them as they decided to stay put for two days, spending most of the time on Burrowes Pit with the odd foray onto Dengemarsh. I spent quite a few hours watching them as the chance to see summer-plumaged birds in the UK does not come along that frequently. One bird was a little mottled on the breast and underwing coverts but the other seemed to be 'fully formed'.

If any species became a birding emblem for the week then it was the Hobby. During my eight day stay, up to half a dozen were seen (or suspected) to have arrived in off the sea at the Point itself, including this individual that pitched onto the beach one dull, damp morning. The RSPB's Water Tower pits was the centre of Hobby action, with a minimum of 22 in the air together last Sunday morning. Any scan of the sky from the reserve usually revealed 6-8 birds at any given time. Magical.

Monday, 18 May 2015

BOOM! (Oh the irony...)

My eight-day stay at Dungeness lived up to all expectations. Admittedly, there were no decent sea watches and no falls, but mid-May is not necessarily the best time for either. My hopes were largely for a few good birds (duly delivered), maybe a migrant moth or two (box ticked) and, just as importantly, a chance to catch up with old friends and to make a few new ones along the way. In these respects it was a week to remember.

So, what will be the subject of my first 'Dungeness May 2015' post? The two summer-plumaged White-winged Black Terns? The Ni Moth? An invert round-up? Or the drake Blue-winged Teal that us Brits found on the other side of the channel in a cheeky smash-and-grab raid? No, none of them, at least not yet. It is the tale behind my belated ability to use the term 'BOOM!' (but only in an ironic way, honest!)

Last Saturday evening (May 16th at 17.20hrs to be precise), I found myself alone in Dennis's Hide on the Dungeness RSPB reserve. It had been a warm and sunny afternoon and I was enjoying the coolness of the hide, scanning the viewable small gravel islands that had been enticing small numbers of waders all day (Turnstone, Grey Plover, and Knot amongst others). A few Black-headed Gulls and Common Terns were present, and as I carried on scanning along the edge of one particular island, came to a gull that immediately got my alarm bells ringing. Surely it had a black - not brown - hood! And its leg colour was a bright orangey red! And it's bill was black!! It certainly wasn't a Black-headed, so what was it?

Although I had nothing to directly compare it to, it seemed small in stature, and in my increasingly agitated state started to eliminate such species as Franklin's and Laughing (although neither were real candidates for this bird) and the black primaries and general shape were wrong for Little. It had to be a Bonaparte's, surely?

I am, by my own admission, a rusty birder. Maybe 25 years ago I would have called it, but my confidence was not up to that. I didn't have a field guide with me (it was back at the observatory) and I frantically tried to dredge out any half-remembered Bonaparte's Gull identification features. The underwing pattern of the primaries! That was something that had stuck, so I made a mental note to look for that if it flew. In the meantime I took in what I could through the scope and decided the best thing to do was obtain some record shots of the bird using my bridge camera. I took maybe half a dozen and checked the back of the camera to ensure that there was something usable, and there was - phew! Looking back to the island at where the gull had been there was now an empty space... it had gone! Bugger!! I scanned frantically left and right, believing my chance to see the underwing pattern had come, but was dismayed not to find the bird at all. After a couple of minutes of this desperate searching I needed guidance. Did Bonaparte's Gull exhibit such leg colour? I knew a man who would know.

Dave Walker answered his mobile but was out in the middle of Walland Marsh. I went through what I had seen, and he made positive noises that it could be a Bonaparte's but clearly needed to see my pictures (and preferably the bird) to make a sound judgement. I returned to scanning the pit, but it was still missing. Did I let the locals know? Had the bird still been present I would have done straight away, but really needed to look at some literature to convince myself that I wasn't making some sort of cock-up. When you lack confidence in your birding you doubt yourself at every move.

To cut a long story short, after spending a few minutes with 'Olsen and Larsson' and showing the returning Dave my images, it all became clear - the bird was indeed an adult Bonaparte's. The locals were duly informed, but further searching that evening drew a blank. A number of lessons had been learnt. One - carry a field guide. It's not dudey to do so. Two - carry a bridge camera. The results may often just be of 'record shots' but these can be good enough to prove (or disprove) the identification of the subject. Three - on a personal level, have more faith in your ability.

Wednesday, 6 May 2015

Pan-list sham?

My pan-listing total is a sham. Read on...

Birdwatching was my entry point into the world of natural history, which is served very well by field guides and populated by a user-friendly subject matter - there are very few species that are not identifiable in the field using just eyesight as a tool. When I started to add butterflies, moths, dragonflies and plants to my sphere of interest I just took it for granted that I would be served well by accessible literature to help identify them - and, to a large extent, I was. Admittedly, it wasn't as straight forward to put a name to a lot of the micro-lepidoptera, and some of the plants (particularly grasses, sedges and rushes) were a big challenge, but all were do-able with patience and the right specialist guides.

So, when I first had the bright idea of finding out what other life forms I had identified in the UK (way before pan-listing came into being), I thought that it would be a simple matter - after all, there must be field guides for everything in a well-studied country like ours, mustn't there? And, to some extent, there were.

For starters, I opened my copy of the Collins Insect Guide (Chinnery), a publication that I had purchased some time in the late 1980s but which had remained largely unopened. Here, I thought, was a book that would be the insect version of the bird guides that I was so used to - comprehensive. And so I began to leaf through the pages, noting down species that I knew I had seen. But here I reached my first hurdle. Not all of the species recorded in the UK were in the guide - not by a long chalk. In fact, for some families, the book just scratched the surface. But I wasn't really aware of this, and if a colour plate of illustrations was set out before me, it was an easy thing to match 'my' insect to the closest one depicted. Metallic green fly? Simple, that must be a Green-bottle. I add a tick to my list.  My errors had now started - there are quite a few species of 'green' flies - even a photograph of one in the RES British Insects book is captioned as Lucilia sp, and this has been compiled by experts. What chance does a birder venturing 'off-piste' stand?

You can take that Greenbottle and add to it many other species, identified by myself in good faith but probably wrong - a bit like starting out birding and calling every phylloscopus warbler that you come across a Chiffchaff, even though some will be Willow and maybe even the odd one a Wood (the latter increasingly unlikely in Surrey though!)

So, my blossoming 'all taxa' list started its life flawed. And it didn't stop there...

A few autumns ago I started to look at fungi and really enjoyed it. Loads of species, some good looking ones too. I had several guides and tried to piece together identifications from them collectively. Again, none of them were comprehensive, but I steered clear of anything that closely resembled another, mainly nailing my ID onto bright, obvious species. Couldn't go wrong, could it? Well, yes it could. My 'obvious' Scarlet Elfcups were not so obvious after all - they could have been Ruby Elfcup. I didn't become aware of that species until the Collins Buczacki guide came out. And what about all of those Waxcaps that I've welcomed onto my list? Aren't they all now being split, lumped, rolled up into a big jelly ball and chopped up again? At least my Starfish Fungus (image above) is straightforward enough - or has a team of European mycologists found out that there are really six different species?

Truth time. My current 'pan-list' is riddled with honest guesswork, all observations that were made at the time with good intent. It should really be binned and constructed again. I bet one or two of my micro moths and plants aren't beyond investigation. But what does slightly comfort me, if we were to take this exercise as purely a numbers game, is that if I've claimed a Scarlet Elfcup (which I have), but it was really a Ruby Elfcup, then it hasn't effected the true number of species that I've seen. But, from a scientific viewpoint, the record is almost worthless. Luckily for me I do not send in my records for groups that I am not confident about, so none of these rogue records are in circulation. If I thought that I had stumbled across something noteworthy then my first course of action would be to notify an expert and get it confirmed. I'm yet to do that.

Because this game is just that to me - a game - I don't lose sleep about it. It is not my profession. If it were then I would need to do something about it. Strangely enough, this realisation that a small proportion of my past records are compromised has only made me more appreciative of the available knowledge and the expertise of many biological recorders. To keep up with the latest developments in taxonomy, identification features and to track down helpful literature takes time and effort. It is a full-time project. And it isn't lost on me that the experts can often revisit their collections only to find mis-identifications. We are all human, after all.

I'm basically a birder - but I also have a moderate working knowledge of plants, moths and butterflies - and I am an expert in none of them. I have a massive appreciation of our natural world. I have a curiosity to find out the names of some organisms that I come across.

I'm quite happy with that. And my pan-listing total? For now, it remains unaltered.