Further thoughts on tree collections: bark

Last weekend it was only raining intermittently for a change, so it seemed the ideal opportunity for a local walk. We followed a valley, walking parallel to a road, a railway and a tributary of the Avon. It turned out to be a strange mix - partly very rural ( ancient very muddy sunken lanes, fields of sheep and lambs) and partly curiously industrial (an urbexer's dream, sadly I was somewhat of a coward without a torch). To get to the point, one of the trees by the stream drew huge attention to itself through its unusual and attractive bark, which was rather like this:

White poplar (Populus alba), CC image by MPF.

It made me reflect that bark would be a very good thing to illustrate in your notebook. It also could help you in your identification in cases of Complexity. At the time (in my ignorance) I thought this tree with its diamondy bark was clearly White poplar (Populus alba), but now I read that this species hybridises with Aspen (Populus tremula), to give 'Grey poplar' (Populus x canescens). So without records of proper observation in the field, I'm not really the wiser. I do know that Grey poplar likes river valleys and has lovely red catkins (as I remember this tree did) - so maybe the clues add up to that species instead.

You've possibly heard of Gustav Klimt (who painted 'The Kiss') - in addition to depicting scantily clad women he also seems to have been quite fond of trees. This is his 'Birkenwald' (Birch wood):

Painted 1903. Public Domain image

I think he captures the stripey paperiness of the birches very well (also I like the dead leaves). Ok so you don't have to take up oil painting, but a quick sketch of the bark in your notebook (highlighting its distinctive features and maybe even with a touch of colour) would go down very well in the eye of the person marking it. And beyond this pragmatic approach, it would no doubt broaden your learning and help you spot different species with which to up your specimen count.

More thoughts on field notebooks

CC image of Martin Moynihan's field notes.

It occurred to me that the field notebook may seem a tad intimidating. All those empty pages waiting to be filled. But with what? Field notebooks, field journals, have always been a staple part of the way scientists work. They're a personal activity and luckily there are few rules about how they should be laid out and what they should contain. They're part of the creative process of how scientists observe, think, interpret and analyse.  This makes them a unique way of accurately recording details and data and circumstances, and can bring to life what you're working on in a way that mere recording sheets or databases never can. If you throw yourself into them, you can produce something of lasting interest and value.

Charles Darwin's notes on the Beagle don't seem to have been neat, but they were obviously legible enough to be useful to him later in developing his ideas. (You might have to work a bit harder on your handwriting so the person marking can appreciate your insights). I thoroughly recommend reading them - they bring his journey to life and are very readable. Here's an extract:

In the low dry region there are but few Tortoises: they are replaced by infinite numbers of the large yellow herbivorous Lizard, mentioned at Albemarle Isd. The burrows of this animal are so very numerous that we had difficulty in finding a spot to pitch the tents. These lizards live entirely on vegetable productions; berries, leaves, for which latter they frequently crawl up the trees, especially a Mimosa; never drinking water, they like much the succulent Cactus, & for a piece of it they will, like dogs, struggle [and] seize it from another. Their congeners* the “imps of darkness” in like manner live entirely on sea weed. I suspect such habits are nearly unique in the Saurian race. 
[* i.e. similar lizard relations.]

One of Darwin's iguana friends (CC image Jimrules42)

You may feel your expeditions around Bristol to find specimens are a little less exciting - but remember, lizards must seem everyday to Galapagos Islanders. Darwin crams in a lot of observations - the large number of lizards, their crowded living arrangements, where he'd seen them before, their vegetarian diet, their fightiness... he also compares the species to a seaweed-eating relation. What similar observations could you make about tracking down your chosen group? Why have you chosen the locations you've visited? You can step back and think about the wider habitat in which your species live (are they seemingly associated with certain conditions or other species?), or if you're collecting animals, can you comment their behaviour? Can you compare your latest find to any similar species you've previously identified?

Darwin collected a lot of specimens on his journey - these were all labelled carefully and matched to entries in the catalogues of his field journals. You need to do this too, showing your organised system (as if I would ever come home with a jumble of poorly labelled pots in my pockets). After all, if you don't know where your specimens came from, they're not much use. And you might be able to copy some characteristics of your species from a textbook later - but it would be much more satisfying to note in the field that your Amanita mushroom was next to a birch tree, and later find out this was a typical habitat. So it's good to make lots of observations actually in the field, and note down any questions that come to mind - you might not remember later.

Back at home (or in a lizard-infested tent), the notes can be mulled over, and interpretations, hypotheses, speculations added in. Thus the 'what' is mostly recorded in the field, but the 'why' and 'how' might come later.

These look like footprints?

You might want to take photos too - but capturing such an image is not necessarily observing, looking, noticing. Which brings me to one of my pet subjects, drawing. Drawing is an active process. You're engaging with what's in front of you and picking out what's most important. With a snappy photo (experienced photographers with appropriate equipment aside), the most relevant details of the scene tend to get lost. A drawing can be annotated on the spot to highlight important features.

It's more time consuming than snapping a picture, I know. But how greatly your notebook will be enhanced by a few sketches. Or failing that, an annotated photograph or printed diagram.

My quick annotated sketch enabled me to later identify this Tenerifean plant as Forsskaolea angustifolia.

When you go to Tenerife (and later if you're off to Cuba or Madagascar), you have to keep a field notebook with more quantitative data - organised tables, calculations, methods, results and conclusions. This exercise won't require much of that type of data. But you can still try to incorporate a certain amount of Order to your notebook - a contents page, page numbers, dates, locations, the habitat, the weather. You should note the sources of any information and underline your Latin names. You can make a separate species list at the back (or front) of your book.

James Arthur Peter's Mexican snake (CC image)

If you can make your notebook engaging and visually attractive as well as being a good scientific record of what you've seen, done and thought about, then you should get a good mark for this section! Effort here may also influence the marks you get elsewhere, because the marker will be able to see how diligently you have gone about identifying your specimens.

There's plenty of inspiration online if you want to see field notebooks belonging to ecologists, anthropologists, archaeologists, geologists and so on. I'd love to get hold of this book: Field Notes on Science and Nature by Michael R Canfield but you can see some inspiring drawings on the link (and this one) in the meantime.

There's much going on online to transcribe such notebooks and make them accessible and searchable - here is a notebook at the Smithsonian which documents gull behaviour in Peru and Chile. There are many such examples at the Field Book Project website. Or for more inspiration just Google 'Field Journal'.

Seaweeds and ferns: a science/art crossover

One of the plates in Atkins' "Photographs of British Algae - Cyanotype Impressions."

You won't know this, but I have a qualification in Printmaking from this very establishment. And so, it's of interest to me that there exists an interesting Seaweed/Printmaking crossover. It's very relevant to the history of Identifying Things and might even inspire you in the display of your own specimens.

Anna Atkins was born in Kent in 1799. Her father was a Fellow of the Royal Society of London, so she had science in her blood (and the advantage of being born into a family where money wasn't a problem). He translated French scientist Jean-Baptiste de Monet Lamarck's "Genera of Shells" into English. And she provided the illustrations of the shells (ah yes I knew I'd squeeze snails into this somehow). You can see them here on Flickr.

But that's by the by really. The point is, through her father she met William Henry Fox Talbot (who lived not far from here) who was the chap who created the first photographic negative image. She took up photography and so would have been one of the first women to do so. Her father also knew John Herschel (son of astronomer William Herschel) who was instrumental in improving photographic processes. He invented the cyanotype. Under his mentoring, Anna Atkins mastered this technique.

Anna Atkins in 1861, singlehandedly supporting the British fabric industry

Cyanotypes don't need a camera. You photosensitise a piece of paper using a mixture of ferric ammonium citrate and potassium ferricyanide. Then you artfully arrange your subject - in this case seaweed, one of her passions - directly on the paper, and leave it in the sun. The sun-exposed areas turn a deep Prussian Blue, leaving a silhouette, but you also get information about the overlap of the fronds, as the sunlight permeates the different thicknesses. The chemicals are then washed away from the unexposed parts of the paper, leaving a negative image. You might be familiar with the idea of 'blueprints' - well this is the original blueprint from which the term arose.

Atkins used this technique to produce the world's first ever book produced entirely by photographic means, which was published in four volumes between 1843 and 53. She'd have to have made them all individually of course! So only 13 copies are known. But thanks to the marvels of the internet, you can see selected plates here at Flickr, or if you're interested, the New York Public Library has all four volumes for you to look at.

I tell you what, if anyone wants to have a go, I've got the chemicals... you're more than welcome.

Highlighting her motivation, she says in her introduction: "The difficulty of making accurate drawings of obects as minute as many of the Algae and Confervae, has induced me to avail myself of Sir John Herschel's beautiful process of Cyanotype [...]". Cyanotype's not very good for handwriting though, I can't read the rest very well! But whatever, as a result of the book, photography was established as an acceptable, accurate way of producing scientific illustrations.

 After this Anna turned her attention to another Victorian favourite, making cyanotypes of ferns.

Atkins' cyanotype of bracken

So there we have it, a female science/art pioneer. However, it wasn't all carefree larking about with plants and chemicals for women in those days. I read in this article which notes that although she was elected as a member of the Botanical Society of London, women members weren't allowed to speak at meetings and nor could they hold office. At least Science has moved on since then (though I hear some golf clubs are still struggling with the concept).

From Bradbury's fern book

I'd also like to tell you about another Victorian method of botanical illustration, that of "Nature Printing". But it's a bit more technical (in fact, details were sometimes Top Secret at the time) and I don't want to bore. One of its chief proponents was Henry Bradbury and he produced the illustrations for Thomas Moore's 'British Ferns'. You'll notice they're very naturalistic - they were made by a process where the fern was directly pressed onto a prepared plate. The plate was then used to print many books, so it was a lot more convenient than the cyanotypes. Bradbury learnt from a master nature-printer in Vienna called Auer, and improved on his method back in London. He also published the lovely Nature-Printed British Sea-weeds in 1860. But very sadly he committed suicide the same year for reasons that are now unclear, and he was only 29.

One of Bradbury's nature-printed seaweeds.

Other seaweed resources inc. a key for identification

'Seaweed Gatherer' by French impressionist Paul Serusier (c1890)

With my current snail infatuation, I know I'm guilty of neglecting other groups that people might be collecting. So this morning I've been looking around for some resources for seaweeds.

I've spotted this key to seaweeds by Emma Wells. She's written it allegedly for beginners. However, it is full of seaweedy jargon... but she does explain it all in a glossary at the start. The pictures are all at the end, whereas it might be nice to have them as you go along? But you will have to see how you get on, and report back. I'm going to print a copy off, so if you come in you're welcome to use it. She's based it on seaweeds at Milford Haven, on the south coast of Wales.

If you're growing to love seaweed as a result of your collecting, you might be interested in Fergus Drennan's 'British Seaweeds in Season' in which he talks about which ones are tastiest. But he doesn't talk very much about looking for sewage outlets nearby, something worth bearing in mind I would have thought.

Dried cochayuyo (Durvillaea antarctica - kelp seaweed for eating) in a market in Chile. CC image by McKay Savage.

Also, I like the information via the FSC's Rocky Shore Species page. There aren't too many species, but there are the common ones you're bound to come across, and each one gets an interesting write-up. It's probably the sort of ecological information you might want to scribble against each species in your field note book after you've identified it.

Another thing you might find interesting is the British Phycological Society's Check-list and Atlas of the Seaweeds of Britain and Ireland. It has all the up to date names for the species and their taxonomic relationships. And this is followed by maps with dots for each 10km square where the species have been recorded.

I rather liked this small selection of species at the BBC's Discover Wildlife site because artist Dan Cole has painted them as they would be seen by something living in a rock pool (hmm. maybe something like a snail...) - they are stretched out and floating freely. I thought this might help inspire you to display the specimens in an attractive way that shows their structure and identifying features. Many seaweeds look a bit sad when they're out of the water do they not.

With this in mind, you might want to look at Seaweed Collections Online which is a project to gather together images of specimens in museums around the country. You can see how other people have coped with the difficulty of squashing a three-dimensional plant onto a two-dimensional bit of paper. The 1850s album on the home page is just beautiful.

spicy seaweed cracker. CC image by Calgary Reviews. I need my dinner.

More on winter tree identification (and oaks)

The Queen Elizabeth oak in W. Sussex. It's pretty big. CC image Pam Fray

I wonder if you've heard of Nominative Determinism... there's a fair bit of it around amongst the staff of the Environmental department actually. Or maybe that's just because lots of British surnames have nature-related themes, who knows. Anyway,  here's a downloadable key to winter trees that I found this morning, to supplement others I've suggested. It's been created by Leif Bersweden (nominative determinism) of the Species Recovery Trust.

I found it via Kevin Widowson's twitter feed which itself has lots of nice photos of winter twigs at the moment. The thought that led me there was about Oaks. I was on a field trip the other day and we went to a local nature reserve that looked at first like an unprepossessing park where people walk their dogs. But actually there were some superb and huge oak trees around its edge. Old oaks are grand and noble and twisty and pretty distinctive with their very blocky bark. But if their rugged outline's not enough, they do have quite an unusual arrangement of buds. As I looked up at the twigs silhouetted against the grey February sky I could easily see the buds were in clusters at the ends of the twigs.

I also found a superb resource from the EU Science Hub Forest project, The European Atlas of Forest Tree Species. It has lots of interesting information on the ecology, habitats and cultural importance of many species (i.e. things you might even want to mention in your notebook). Also, you can make some taxonomically-relevant comparisons - I was reading about goat willow (Salix capraea) and it compares the different soil moisture / light preferences etc. of different willows.

There are also pages about the two native oaks in the UK, the English oak (Quercus robur) and the Sessile oak (Quercus petraea). For some reason I've never been able to get all the names and features of the two species straight in my mind. So here is my attempt to. It sounds like they should be readily distinguishable even in winter when the usual things you'd check (the leaves and acorns) are not about.

Quercus robur (CC Sten)

Quercus petraea (CC Sten)

Quercus robur                                      Quercus petraea
aka English oak                                    aka Durmast oak ('mast'=acorns)
aka Pedunculate oak                             aka Sessile oak

buds are ovoid                                      buds are pointy
buds are hairless (although                  buds have long white hairs
  may have fringey edges)
buds are said to have less                     buds are said to have more
  than 20 scales                                       than 20 scales


'Pedunculate' and 'Sessile' are words meaning 'stalked' and 'stalkless' respectively. But my problem has always been to remember to what they refer.
Q. robur  has pedunculate (long stalked) acorns, but (confusingly to me) a short stalk to its leaves.
Q. petraea has sessile (stalkless) acorns, but a long stalk to its leaves.
You might think this is a bit of an academic point in the winter, but it's always worth a look in the leaf litter for clues.

It's also said that Q. robur has blunter-tipped acorns than Q. petraea. And I've read different colours for the descriptions of the twigs. But colour always seems a bit too subjective to me, especially if you've only got one specimen in front of you. It's more the sort of thing you get a 'feel' for as part of the overall character of the species, that you might notice once you've seen and examined quite a few trees.

Their outlines, due to their way of growing, can also differ - Q. robur supposedly spreading out with irregular twisting branches and the main trunk still large and visible in the crown, whereas Q. petraea is ideally more orderly with a straight main stem and straighter branches in sensible size order. Of course, their appearance will depend on not least where they're growing - on their own or amongst lots of trees in a forest. And their age. So I don't think it's entirely clear cut.

Quercus robur, being the arboreal symbol of England, is, unsurprisingly, found in the lowlands of England. Quercus petraea is native to the oak woods of Western Britain. So you should probably be on the look-out for both. Also, to confuse matters (as ever), the two are quite variable and can even hybridise, producing trees with intermediate characteristics. Thanks a lot, trees. People are determined to pigeonhole everything into separate categories. But you confound us.

Oak leaves and flowers (male catkins) emerge from the buds. CC image Kenraiz

Further snail enthusiasm

Clausilia bidentata. CC image Hectonicus. You too can find one of these.

I had a day off last week, but when my sister and I went for a walk, we couldn't help ourselves and started rummaging through the leaf litter for some snail shells. Yes, it seems my blog has inspired one person, even if it's not someone who has to submit a collection. I see this as a minor triumph.

Altogether, I now have about 22 species. That would make you a pretty nice collection. It's not too hard to find so many - mine have largely come from flowerbeds and leaf litter, with a few that are particularly fond of woodland or limestone.

I cannot help thinking of one of the more depressing collections of recent years, which comprised a series of garden snails (Helix aspersa) arranged in a supposedly artful spiral, with a variety of imaginative identities attached. You don't have to do that, it's just not necessary when there are so many species that you will be able to find.

I've just noticed that my copy of Cameron and Riley's 'Land Snails in the British Isles' is the first edition, so now there's a second edition, it might be that the keys are even more straightforward to use. But don't be downhearted if you get stuck - even Cameron says "It is to be expected that some material will be unidentifiable."

I'm building up my collection of labelled specimens (and I know the ones I'm most/less certain of) - so if you want to bring in your own, we can always compare shells and opinions - I'm sure we'll both learn something.

Snails in February... a report back.

In solidarity with aspiring snail-hunters I went for a wander around campus yesterday. I've got some observations you might find helpful.

Winter snail hunting is cold and it makes your hands cold and filthy and damp. Clearly you can't wear woolly gloves or you'd ruin them. But if you're feeling particularly delicate you might want to wear some lab gloves. I didn't wear any, but I might have felt slightly less apprehensive about the random slimy touch of cold slugs if I had. You're going to have to poke about through a lot of mud and gack.

In fact, the best thing you could have with you is a good stout stick - perfect for raking through muddy leaf litter and stirring up the dirt. I couldn't seem to find one, which meant I was at the mercy of spiky brambles, bits of glass and other unknowable debris.

Also you want a bag full of pots (for shells that you find in each location) and some sealable plastic bags (for handfuls of leaf litter that you can search through later). And a pen to label those things with your location. I've got plenty of pots you can borrow.

It'd help if your bag is waterproof so you can abandon it anywhere while you search - everywhere at the moment is damp. I've got a rather strange plastic box with a shoulder strap which is rather good (plus it's unsquashable so samples survive). You're inevitably going to have to put your knee on the floor, so something waterproof to kneel on is good. I mean you could wear waterproof trousers, but you're going to look odd enough as it is, so I'll leave that decision up to you.

CC image by Colin Smith

So I searched in the vegetation around the ponds by hand (difficult, and no luck) and I also hunted amongst leaf litter (productive) and amongst moss and around tree roots. I wandered down to the 'suds system' valley with the ditchy stream in the bottom - that's got a lot of long dryish tufty grass to stir through, and then there's piles of half-rotting vegetation by the stream itself. I know. I make it sound so glamorous and romantic. But I did find a few down there as well.

I think it may not be the easiest season in which to look. But there's certainly plenty out there and you will find decent empty shells as well as hibernating and lively snails. I brought my finds back to the lab. I thought I could easily pour some boiling water on the live ones to see how difficult it would be to extract them from their shells. It turns out I'm far to soft for that. Especially once they stuck out their cute little eye tentacles. There was no chance after that. But if you're as soft as me, I am confident you will still find enough vacated shells to produce a decent collection. Just make sure they're in good condition or you will confuse yourself (it's not helpful if they lack the mouth lip or shiny surface or even hairs that they should have... take it from me).

CC image by Santeri Viinamäki

You will need to measure the shells' widths and heights. For that a pair of vernier callipers is good - I've got some you can borrow so please ask. Also, it helps a lot if you can draw your snail, as it makes you realise how tight or loose the whorls are, and helps you concentrate on the shape of the mouth and relative pointiness of the spire, which are important identifying features. This is not easy if you're squinting at it through a handlens whilst trying to hold it. So I do recommend steadying your shell on a bit of bluetac. I had mine under a dissecting microscope (something you are welcome to come and use) and this was great. Other than one thing: the magnification makes little features like ridges seem so obvious that you wonder whether you're interpreting the key correctly. That's my only reservation.

I used a combination of keys - the Bristol key is pretty good but it's not got much detail, so where there are similar species you can't feel confident which one is correct (plus I noticed a problem for unstripey Cepeas). So Cameron's key was of most use. Plus I did look at the drawings in Kerney and Cameron and I should look at some of the photographic resources online (like AnimalBase).  I think sometimes the proportions of the shells are really important, and maybe that's something that's easier to "feel" with a photo than try to rationalise. That doesn't sound very scientific. But perhaps it's a good step on the way to Recognising your species - an expert identifier's brain puts together lots of clues at the same time. Yes I'm trying to get you to use keys, because without an expert explainer on hand to guide your every step this is definitely the way to start - it'll focus you in on what the important defining features are of each species. I realise someone who Knows Their Snails isn't often likely to be working through a key in their head, it's more about pattern recognition. But the whole Keys thing is probably a subject for another day. Meanwhile, back to the snails.