Wednesday, 4 November 2015

The odd one out

Daffodils are spring flowers, we all know that.  But this is natural history, and there are exceptions to almost every rule, just to make like life difficult or interesting, depending on how neat and ordered you wish the world were.  There are four or five autumn-flowering Narcissus in Europe, including what I think of as the strangest of them all: the green-flowered Narcissus viridiflorus, the object of today's excursion to the south-west of Los Alcornocales National Park.

This daffodil has a refuge along the road to Cañada de la Jara.  The narrow verges between the fence and the road are free from grazing animals, which seem to have done their best to eat off any flowers that might be foolish enough to try blooming inside the enclosure. Not the most alluring of localities for a rare plant, but at least it seems to be here in good numbers.

The plant itself is alluring. The fist pictures I saw of it, in John Blanchard's book, made it look rather ungainly. It did not have the brightness of the yellow or white daffodils, and the photo was not as pleasing as those of the other Narcissus. It stood out because of its almost ugly appearance, and the poorer photograph strangely added to its appeal. I have noticed this before: the perfectly composed beautiful poster shot is stunning and makes you feel glad to be sharing a world with whatever it depicts. But the image of a plant or a bird that looks as though it was taken under trying circumstances has a different effect that can be just as engaging. The message here is different. Rather than portraying beauty, this picture tells of a precious moment, so rare an event that there is only one chance to grab whatever image you can. No chance to try again or to find the prefect angle on a well lit plant against a pleasing background. These are rare encounters and you take whatever you can from them. The words describing the European distribution of Narcissus viridiflorus confirmed the impression given by the photograph: 'limited to a small area around Algeciras'.  Here was a rarity and a challenge. As previous autumns had turned to winter I had thought about going south and plant hunting again, but I was always too late. This year my wanderlust had arrived just in time, so I set about turning the fantasy of an encounter with this strange plant into reality.

In life it was almost as I expected it to be, but the glaucous bloom, an illusion from many tiny white dots on the flowers, was a pleasant surprise. The flowers were as narrow and star-like as the pictures promised, and it was indeed difficult to spot amongst the general greens of the countryside. Because this is such an uncontroversial daffodil I cannot make my usual comments on how hard it is to identify and how its names have been fought over by various botanists: it is an uncomplicated plant that we can simply enjoy.

The daffodil shared its road verges with Late Crocus Crocus serotinus, a much more widespread plant, found through most Iberia. The familiar bird's-nest fungus Cyathus olla was here too, growing on small twigs.  Its nests were at various stages, from fully covered kettle drums to wide open baskets revealing their clutch of mini eggs at the bottom.

Thursday, 7 May 2015

Is this the cutest spider?

There are lots of special things at Dungeness.  The biggest bit of coastal shingle in Britain is a strange place: flat, treeless, windswept, and wild if you can manage to ignore the huge nuclear power stations in the background.  Yet somehow it manages not to feel bleak, and every time I visit I get excited at the possibilities offered by a day here.  You see, whatever branch of natural history has taken my mood I know that there is a chance of finding a great rarity at Dungeness.  If I am feeling botanical there will be an abundance of Nottingham Catchfly Silene nutans and the tantalising prospect of discovering Stinking Hawk's-beard Crepis foetida in a new spot.  If my mind is on beetles I will go to the quicksand shores and search for Omophron limbatum, or venture out at night and look for new weevils.  And there is always the possibility of vagrant birds to liven up the day.  But today we were focussing on spiders, not on a whim, but because we wanted to check on two of the Dungeness rarities: Three-spotted Jumper Pellenes tripunctatus and Banded Jumper Phlegra fasciata.

Both these spiders have the distinction of being rare and easy to identify (an unusual but much appreciated quality).  We arrived late morning on a windy but sunny day and started crawling over the shingle.  There were plenty of jumping spiders out and about around the car park: Common Zebra-spider Salticus scenicus was the most noticeable, but there were plenty of sun-jumpers Heliophanus around too.  This boded well for our search, so we headed out hopefully onto some of the vegetated shingle near the pits, where Steph, one of the wardens who had joined us for the hunt, found our first Phlegra fasciata.

It was a female, which was a relief for us all.  The males are black and not so distinctive, but our girl had the pattern of broad velvet stripes down the abdomen that made her at once identifiable as a Banded Jumper.  Chloe found another, smaller one a few minutes later.  Things were looking promising, but these turned out to be the only ones we saw all day. At least we were able to confirm that it is still here.  In Britain, Phlegra fasciata occurs at a few places along the south coast and in south Wales.  It seems to have always been uncommon at Dungeness, or at least hard to find, so we were not too discouraged by our meagre total.

Our first Pellenes tripunctatus appeared soon after.  At Dungeness, people have found this spider more commonly than Phlegra fasciata, but nationally their statuses are reversed and Pellenes is much the rarer of the two.  It has an interesting history, which begins with Octavius Pickard-Cambridge telling of its discovery:

'Adults of both sexes of this fine addition to our British spiders were sent to me in June, 1888, by Colonel Le Grice, by whom they were found at Folkestone in that month.'

However, the excitement of the initial discovery did not live up to its promise, and by the 1950s British arachnologists seemed to have given up on it.  In British Spiders Vol I, we are told almost dismissively that it 'has been found but once, at Folkestone (Kent) in 1888, when both sexes were taken.  It has never been re-discovered and may have been the result of a chance importation of a cocoon.' Hope was restored in Vol III in 1974, with the recent finding of an immature male at Dungeness.  This was enough to inspire Dick Jones to try his luck with the spider in April 1981.  He found it, and it has remained a firmly established member of our spider fauna ever since.  Dungeness and Rye remained the only known localities for it until 1994 when Pickard-Cambridge's prophecy that it ought to be found in Dorset was fulfilled with the discovery of populations at Chesil Beach.

Pickard-Cambridge does a good job of describing it, so I will leave it to him again to tell you more:

'It appears to be an exceedingly active spider, and the extent of its leaps is wonderful. It lives among stones and rubbly chalk near the shore, and comes out during the hot sunshine. The very striking pattern on the abdomen will serve to distinguish it a glance from all our other British salticids.'

It certainly will, and it was this pattern that first caught my eye as I was crouched over a patch of shingle hoping to find another Phlegra. Pellenes tripunctatus is a large jumping spider, and the females are adorably cute with two large sad-looking eyes looking out at you from their fluffy cream palps and face mask.

The males are not quite as cute, but they are very striking in their red bandit masks and chalky white stripes.

Over the next few hours we found 36 Pellenes out on the vegetated shingle; a good count for the day, and confirmation that it was still here and thriving.  I wonder, how did this spider, described by Pickard-Cambridge as 'a conspicuous object' go missing for so long?

Wednesday, 29 April 2015

The real thing

The Trachyphloeine weevils are strange but endearing animals.  The one I find most often, enough for me to call it common, is Trachyphloeus angustisetulus, and yet this species was first found here as recently as the early 1990s.  It has a doppleganger in Trachyphloeus bifoveolatus, from which it was separated in 1915.  The differences between the two are subtle and variable, so much so that fifty years after he had described angustisetulus as a species, Victor Hansen decided that it was only a variety of bifoveolatus.  In Britain, any big fat Trachyphloeus was still being called bifoveolatus, so none of this mattered much until 1991 when a team from Aarhus Univeristy found that allozymes and measurements offered strong support for separating the two, and that both species were British.  Equipped with new and more reliable ways to tell the two apart, British entomologists looked at old specimens and found that angustisetulus was much the commoner species here, even though it had been recorded under the name bifoveolatus (or scaber just to add to the confusion) until now.  As a result, any mention of bifoveolatus from before 1990 could refer to either species; caution is required.

That is the past.  We are now left with two species, but how do you tell them apart?  The real bifoveolatus (on the right) is usually not so fat, and it has slightly longer and less rounded eyes.

In case you are not convinced, here is a composite image with bifoveolatus on the right: the wing-cases are narrower, and they are not so swollen at the sides, especially just behind the shoulders, and the eyes are a little flatter.  The difference is apparent in the field.

I said that bifoveolatus is usually narrower than angustisetulus.  The narrowest angustisetulus are as wide as the broadest bifoveolatus, but the area of overlap is small.  Things seem to get a bit more blurred in Central Europe, where people have had the most trouble separating the two.  Peter Stüben argues that the shape of the spermatheca (one of the female reproductive bits) is the only way to be sure.

You can measure the difference in shape if you divide the width of the pronotum (P) by the width of the wing-cases (W).  The Aarhus team measured the mean and standard deviation of W/P in the two species: 1.427 (sd = 0.043) for bifoveolatus; 1.628 (sd= 0.053) for angustisetulus, so we can plot frequency distribution of the two.  I have added W/P from my specimens and from some photographs (1-10).  Specimen 1 is the bifoveolatus I found on Sunday; 2 is from a photograph of another weevil from the same site.  3-10 are specimens from various places.  I am happy to call 1 and 2 bifoveolatus: their wing-cases are narrowed to the base, they have flat eyes, and the spermatheca of 1 matches the pictures in Peter Stüben's article.  I am also happy to call 3-10 angustisetulus because they have very rounded wing-cases, broad, rounded shoulders, and rounder eyes.  

As a final note, I should add that the latest British checklist includes these Trachyphloeus species as Romualdius angustisetulus and Romualdius bifoveolatus.  The genus Romualdius was created in 2009, and it incorporates two things I dislike: nomenclatural meddling above the species level, and naming things after people.  But as far as the British species are concerned, the new arrangement better reflects the differences between the various groups.  The Trachyploeines fall neatly into three groups, which now correspond with the redefined genera.  Each has a characteristic head shape formed by the eyebrow ridges; Romualdius looks like a hippo.

I have covered the Trachyphloeines in the draft guide to broad-nosed weevils.  Many of them are rare, so I am missing photos of most species, but the text might still be helpful.  The latest version is here:

Friday, 20 March 2015

Slow progress


I have been doing lots of little bits on the weevil guide, but nothing yet amounts to a sizeable chunk that deals with a single group of species.  It feels like I have little to show for my efforts, but it is useful to know how I am doing.  So I have put two accounts, one to Polydrusus and one to the wetland Gymnetron, and a guide to Sitona here:

I am afraid the Polydrusus is incomplete because I have photos only of those species I have found, so it cannot yet be used as proper guide, although it does have all the metallic green ones.  If you want to take a look at the sample accounts, please download them and leave comments on this post to tell me whether you can happily and successfully identify weevils using them.  It is very useful to know how well they work for other people.  Since I started this, I have become much more forgiving of those who write identification guides.  One of the problems is that those who already know how to identify things often forget what it was like before they had twenty years of experience with the species they are trying to help others to name.  I do not have that problem so much because I have taught myself how to identify weevils by writing a guide, so I am much closer to the state when I knew very little about them.  Nevertheless, I still fear that I do things that work for me and not for other people, so your responses will be useful.  I am still not sure how to lay it out.  I have prepared species accounts in a field guide manner but I also have character tables, which are a bit more structured.  I will try to get some of those up soon.

Thursday, 19 March 2015

Turning things over

Winter was back again today.  Not for us the bees at the flowers and the bugs scurrying across small patches of sand warmed by the sun.  Things would be trying to escape the cold and we would have to annoy them a little by exposing them if we wanted to find them.  Time to turn things over.  This can be very rewarding, but I do find that I often need to turn over a lot of things before I find something good.  If there is a way of knowing which logs or stones are going to be sheltering the most exciting insects, I have not yet discovered it.  But I can report two successes today.  The first was Endomychus coccineus.  This is a bright red beetle and by that alone it qualifies as exciting.  It has a rather waxy finish to it, which, together with its vivid colour, make it the beetle that most looks as though it is made of plastic: if it could be trained to sit on a cake it would be a pretty decoration.  Its real lifestyle involves eating fungus under the bark of timber, which is probably better for it than a diet of icing.

Success number two was much more unexpected.  I lifted a stone in the wildlife garden and saw an unusual pale lemon-sulphur slug.  Both Col and I were immediately reminded of a day four years ago when he found Testacella haliotidea on a nearby wall.  This had to be it again.  We brushed off some of the soil, and our suspicions were confirmed when we revealed the small shield-like shell.  Such a meagre shelter could never accommodate the body of its bearer, so Testacella is usually called a slug rather than a snail.

There are four Testacella slugs in Britain.  One of them, maugei, is brown, and the two deep lines on its back are rather far apart where they disappear behind the shell.  Our species, as you can see from the photos, has the lines almost meeting before they vanish.  In the other two, the lines meet before the shell.  Interestingly, the other two are Testacella scutulum and an unknown entity, which may or may not be an undescribed species.

All the Testacella species in Britain are probably introduced.  Our one was noted in gardens in several places by the middle of the 1800s.  It is widespread but patchily distributed, though its real range and numbers are hard to know because it is a difficult thing to find.  It spends most of its time under ground pursuing worms to hoover up, so it is rarely encountered.  At the 2011 sighting, Malcolm described seeing his first shelled slug as 'a childhood dream come true'.  It had taken us four years to get a second chance for any other malacological dreamers.

Thursday, 5 March 2015

The trouble with spiders...

Over the last week it has felt like spring has arrived.  It is still standing in the corner with its coat on looking as though it might decline the invitation to sit down and make itself at home, but nonetheless, it has at least shown up.  To celebrate, I have been hitting trees.  Some of these have showered me in Birch Catkin Bugs Kleidocerys resedae that have found Scots Pines suitable places to spend the winter while waiting for birches to get some leaves and catkins back.  Among them have been a few nice things.  Today they included a Box Bug Gonocerus acuteangulatus and several ladybirds: Seven-spot Coccinella septempunctata, Larch Aphidecta obliterata, Heather Chilocorus bipustulatus, and the prize find of Cream-streaked Harmonia quadripunctata.  I have seen this three times before according to my records, but I could not remember any of the previous encounters, so when one fell out of a pine today it brought a satisfying smile to me.  This beetle was first found in Britain in 1937 in West Suffolk.  The plantations of the Breckland are just the place where an immigrant pine-loving ladybird could establish itself.  They are also just the place where it might be introduced with trees.  So Harmonia quadripunctata could be a natural colonist or an accidental importation.  Or both.  It has managed to spread west and north, and it is now well established in eastern England, with outposts in the south-west and in Wales.

The wing-cases of this species are edged with a streak of pale cream, interrupted by two black dots on each side: a distinctive pattern among our ladybirds.  Some individuals have another six spots on each wing-case, others, like today's insect, are plain red above.

Last week's beating produced more netfuls of Kleidocerys resedae, and this rather lovely spider.  A green abdomen with two horns on the top endeared it even to Andy, who does not take well to arachnids.  There are three such British orbweavers with prominent bumps on their backs.  The field guides tell me that they all have distinctive palps, but they offer no other advice for separating them. This is one of the frustrating things about spiders.  If a species has a distinctive palp or epigyne (the reproductive bits), the authors of some guides often have no more to say about them.  Many spiders resemble one another or are so variable that the palps or epigynes are the only way to separate them.  However, there are species or groups that have distinctive patterns or shapes that could help name them, but these features are not mentioned in the text.

British Spiders by Locket and Millidge is the only guide that is helpful enough to start off by telling me that there are three big orbweavers with humps on their back.  It is also forthcoming with non-palpal information, so despite my spider being an immature male (and therefore not having identifable palps), I am going to call it Gibbaranea gibbosa.  According to the book, male gibbosa are sometimes green and they have an all-dark sternum, both of which match my spider.  The other two humped orbweavers are Gibbaranea bituberculata, only ever known from one place in Berkshire and not seen for decades; and Araneus angulatus a rare spider, found only south of London, which has a yellow mark in the middle of the sternum.  Is this cheating?

Monday, 26 January 2015

A cat

We were up early and braving the cold before we started the drive to Los Escoriales.  Our destination was only 7.5km away in a straight line, but we were not taking a straight line to get there.  We had a detour on tortuous roads down the valley, on tortuous roads up the other side, and on a tortuous road across the side of the hill.  After an hour, we made it.  There were a couple of stops on the way: one for a group of Hawfinches in streamside tree, another for two Iberian Green Woodpeckers that had found a telegraph pole to their liking.

Then we started the scanning and waiting.  Most of the recent lynx encounters I had heard of had taken place along this track, so we settled in and hoped.  We potentially had five days of this ahead.  There were other things to look at while we waited, the most exciting of which, in my minority opinion, were the jonquills by the side of the road.  But it was early in the day and I was saving them for later when there were likely to be fewer mammals around and there was less chance of being focused on measuring flowers at the moment a lynx decided to cross the road.  For now I was content looking at some distant Mouflon on the opposite slope, and my first Wild Boar rootling in the valley.  And plenty of Red Deer.

There was a clear sky, and as the sun appeared over the hill the birds warmed up and we could see the Santuario Virgen de la Cabeza teasingly reminding us that where we had set out from was really not very far away.

We were joined by other lynx hopefuls, but even with more eyes looking there was no sign of any cats by midday, so we headed down the road to the dam at La Lancha for a change of scene.  I am not good at staying in one place and waiting, which might explain why I have not seen many seabirds or mammals, both of which are well known as the rewards for those who patiently sit and wait.  I much prefer to go looking for things or at least to be doing something to try to find my quarry, otherwise I do get bored.  I would say I have child's attention span, but I am sure I was better at sit and wait when I was a child.

Down by the reservoir, Bex picked out a young Spanish Imperial Eagle flying along the far side of the river.  It was a tawny below, with pale patches on the inner primaries, and a white tail base above.  Just like the book said it would be.  Hurrah.  From the dam, we looked down on a party of Spanish Ibexes crossing the river.  When they reached the near side, three of them began play-fighting.  Or rather two of them did, rearing up on their hind legs, slowly leaning back in towards each other, then toppling and crashing down with a crack of heads.  The third, with bigger horns, seemed more intent on mounting the others.  The two fighters seemed unimpressed and undisturbed and to carried on their mock battle regardless.

I assume that this entertaining and endearing spectacle gives them some practice at the things they will need to do under more testing circumstances later in life.  As well as being fun.

Back at the lynx track, I was pleased to find out that we had not missed anything.  The Mouflon had come a little closer, and a Spanish Imperial Eagle flew around, with bright white shoulders, just like the book said it should have.

At about 1600, there was a clicking of fingers from down the track: one of the tour guides had glimpsed a lynx.  It had gone out of sight, but we knew where it was heading, so we kept scanning.  At about 1800, someone saw it again.  That was a long time for a lynx to stay hidden.  Unfortunately the person who know knew where it was was not helpful with directions, saying nothing more than 'está en el matorral' whenever he was asked where he was looking.  Reference to the photos above will demonstrate that 'it is in the scrub' is not a very useful reply when the entire view around you consists of scrub-covered hillsides.  The lynx disappeared again and by now the sun had gone behind the hill and the light was going.  Dammit.  About ten minutes later, we got a second chance, this time from someone who was able to say something a bit more descriptive, and I found myself looking at a brown, black-tailed, ear-tufted, long-legged cat strutting up the hill and slinking away around a large rock.  I had seen my first wild cat [this sentence is a lesson to anyone who thinks that species names should not have initial capital letters: you are wrong].  Bex saw it too, so we were now free to enjoy the rest of the week exploring, and measuring as many daffodils as we cared to.