Darwin's worms (and mine)

now the Darwin-hype of last year (2009) is over we can return to some real, simple and enjoyable biology, rather than grandiose theorizing about evolution, natural selection (which must be a prime competitor for one of the worst generally understood, wrongly interpreted and politically charged ideas in human history, more even than global warming and climate change) and all that jazz. Not that I am a “non-believer” when it comes to evolution or, god-forbid, a “creationist” or “intelligent design” adherent. Far from it. But I am simply not that interested in trying to solve the riddle of life, the universe and everything (the answer to which is 42 anyway); no, what grabs me is what is happening around me and what I can see. Now!

nor am I rubbishing Darwin’s, Victorian “scientists” and their predecessors’ contributions and efforts to the advancement of our knowledge and understanding. Victorian “scientists” in quotation marks because nowadays many of them would not qualify or be accepted as such as they neither had formal training in the subject of their interest (and that includes Darwin), nor PhD’s or, initially anyway, positions in academia. Those were the days of the “gentleman (or woman) scientist”, and in particular what we would now call, disparagingly, naturalists: hobbyists with an interest in nature but whom we don’t have to take seriously as they neither stem from the hallowed halls of academia, nor, necessarily, follow the pure scientific method, so we don’t allow them in print in our august scientific journals.

actually that is not entirely fair; it wasn’t always that easy to get in print in those days either. Audubon was originally a shopkeeper but drew and painted birds superbly, Thomas Nuttall (who had a habit of getting lost on expeditions and having to be rescued by search parties or passing Indians; in fact he managed to elude one rescue party for three days, thinking they were marauding Indians until, entirely by accident, he wandered back into camp, closely followed by the search party…) was a printer himself, so they probably found it easier than most. Darwin had the right connections and patronage, Mendel, well… he was a monk and they have their own celestial means of getting something in print. Carl von Linné, or Linnaeus as he is better known, did have a doctorate but from the University of Harderwijk in Holland, a degree mill in today’s terms, and which took him a full week to obtain, most of which was spent printing his dissertation. Ironically, getting in print if we include the internet these days is a hell of a lot easier; acceptance of ideas and what is “in print” however a lot more difficult thanks to the vested (public grant-funded and funding) interests, scientific community structures and very rigid “scientific method” criteria.

no, in fact I long back to those days when amateurs (in academic terms) could design an experiment, toy around with it, form and shape ideas and put them out there for general but serious discussion. Probably the UK-trained engineer in me, which gave me that “what the hell! Let’s just try it and see what happens…” attitude. My love for initially unstructured but interesting work and experiments, slowly shaping and modifying them until eventually, maybe, something useful or usable come out of them. Or not as the case may be.

and that was Darwin too… his best and most overlooked work was his study on the formation of leaf-mould and soil by earthworms, and a prime example of a “home and garden” experiment (what else can you call an experiment which included playing tin whistle, bassoon and piano to worms and see what effect that had – try and do statistics on that…) working wonders. That experiment, started in flowerpots in his study, evolved into his worm stone; a circular stone with a hole in the middle, placed on the lawn of his house and the depth of which it sank into the soil thanks to worm action measured for years and over a period of years (by his son admittedly), leading to estimations of soil turnover rates etc which still today have relevance in many areas, not just gardening and agriculture but even archaeology and dating of finds. And what started it all was his fascination with worms… just like mine.

I wont go into the details of how that fascination started, but it was finally anchored, many years ago now, when I received a £60,000 proposal from some harebrained fool (an engineer and biologist like me, sadly), to deal with a heavy metal problem on an ex-sewage sludge landfill area under my responsibility by releasing, studying and monitoring thousands of worms in the problem area, as these animals eat their way through soil and organic material, accumulating the heavy metals in their body fat and removing it from the soil. “But that still leaves it in the landfill” I said “so there is no change”. “Ah no”, he said, “they will only stay there as long as there is food, organic material, and when that runs out they move away and disperse, thus removing your metal problem”. The solution to pollution is distribution eh… the devil buys souls cheaply this day and age!!!

but ever since I have been playing with worms, on and off, be it for gardening, fishing bait, more serious study purposes or as food for my newts. The latter required me to get a constant supply of the critters which forced me into having a good look at my compost heap and constructing my own worm farm. During the summer my composter in my back garden supplied plenty of worms but I realized that for the winter I had to do something else as I wouldn’t be able to get any. So I looked long and hard at many different designs, all of which far too complex to my taste and more suited to community or industrial worm system than my newt food supply. I considered purchasing “worm bin with guaranteed stock of healthy, parasite-free Eisenia foetida “(red wrigglers to you and me) but the cost and the idea of having them delivered by mail and then having to find sufficient food for the worms put me off. So I decided to do my own thing.

although there are many species of worms, they basically come into two varieties: those that are living in rotting vegetation and compost like Eisenia foetida, and those that are real soil dwellers like Lumbricus terrestris (the night crawler). Both types though are good for fishing by the way, some species of each better than others, but my newts prefer the rotting vegetation dwellers which has probably nothing to do with taste, but all to do with their vigorous wriggling, even in a dish under water for days, which persuades them after long, long and repeated study that, yes, they are alive and probably food….

breeding worms is easy, albeit surprisingly slow and therefore takes serious patience and a little bit of thinking. The worms are hermaphrodites, which means they have the “bits” of both sexes in each of them. It is male and female at the same time but it cannot self fertilize; it needs another worm for that. That is pretty handy for our worm farm as that means we don’t have to sex them; as long as we have two to start with (the more the better though)we’ll get more eventually. Once a worm has mated and deposited the now fertilized egg capsule, it takes about 2-3 weeks for it to hatch, producing tiny but fully formed and active worms. To reach full adult size takes about a year reproductive capability 60-90 days though. So what do we need for our worm hatchery… Nothing but three buckets (one with a lid) and a small compost heap.

go to your local Tim Hortons (in Canada, some places in the US and the Canadian Army base in Kandahar, Afghanistan- the rest of the world will have to wait a bit but eventually they’ll get there as well no doubt) and ask for at least two, preferably three empty fondant buckets and lids. They’ll be pleased to get rid of them but for our purposes these buckets are perfect as, for some unknown reason, they are fitted with three outside rims which means that when you stack them there is about a hand-width of empty space between the bottoms. Drill a series of small holes in one of the bucket bottoms, the more the better, lid on, place that bucket on top of the second bucket (lid off!!!!) and, voila, the farm is ready and of convenient size to be kept in the kitchen at least during the winter. Saves a daily trip outside to the compost heap in the snow as well.

now go to your (or somebody else’s) compost bin or heap, dig in it for a bit and, if yours is like mine (I can never get the damn thing started or really going anyway) there will be plenty of worms visible. If not, throw a bucket of water on the heap and dig again lightly, you’ll see them coming up despite their strong dislike of light. Throw a couple of handfuls of soil in the top bucket and start picking out worms and throw them in the bucket. Keep digging and raking lightly; the worms will try and move out of the light again as soon as possible so be quick and methodical.

no need to worry about sex, as I described earlier, nor is there any need to worry about which species. Although it depends a bit on where you live, many species are pretty universal and to determine species accurately requires techniques and equipment that are beyond the capability or reach of most of us. Red wrigglers come in many colours and many stripy patterns, and if they are not wrigglers it doesn’t matter; the fact that they live in rotting vegetation means they are suitable, whatever species they are. The more the merrier. Add some fresh vegetable material to the surface, some shredded paper and coffee grinds, and put the stack of two buckets in a warm place, kitchen will do nicely, with the lid on loosely!

do not be in a hurry and put all the vegetable waste in the bucket every day for starters. Not until you have a very substantial worm population will they be able to deal with that much every day and that takes some time. Put too much in and you will have a successful composting bin inside your kitchen, which, trust me, is the last thing you want! The fresh material will keep the soil in the bin moist, whereas the holes in the bottom of the bin will allow excess moisture to drain out into the second bucket.

maintenance couldn’t be easier. Regularly, every few days or so, rake and dig through the bucket a bit with a hand trowel, loosening the soil up and mixing the fresh vegetable matter in. That will give you the chance to see your worms, how they are doing and how many, as well as to decide whether you need to put some more vegetable waste in. If, when you open the lid, you see large numbers of worms clung to the side of the bucket, that usually means they are trying to escape (still, as they try to in the first few days anyway), probably because the contents of the bucket are too wet or, more unlikely, the food is running out. As a rule, if it smells, it is too wet (or you are composting!).

this is where you need the third bucket: tip the worm bucket over and empty it into the spare one.  Hose the inside and outside of the now empty worm bucket with water; your drain holes were getting blocked with soil. Check whether it drains again properly and put your worms and soil/vegetable mix back in. I like putting a couple of handfuls of “dry” soil in it as well to restore dampness rather than wetness. Actually make a habit of doing that every two or three weeks and don’t wait until the worms are trying to escape or dead. The liquid contained in the second bucket is generally known as “worm tea” and is phenomenally high in nitrogen and therefore a good fertilizer or compost starter!! So tip it on the compost heap to finally really get it going, or anywhere else you want fertilizer.

and now it is time to start studying your worm bin. Don’t bother with the tin whistle; Darwin already determined worms only respond to piano music (although of course in his days he didn’t have a synthesizer… that might be worth a try), but then of course he was studying more soil inhabiting worms, not necessarily ours….Determining how fast the level in your bucket drops though over a given time is or can be fun and useful as a measure of how much worm biomass you have in there and what their metabolic rates are, which depends also on type of food. I put some pineapple tops in there which took them months to make disappear, even with a large number of worms, but they went eventually.

or watch them mate and behave otherwise. Hours of fun and actually we don’t know that much about worm behaviour other than the most obvious and common things. Don’t handle them for too long though; there is a reason why Eisenia foetida has that name… when panicking or under attack it releases a foul smelling (fetid) liquid. Alternatively you can collect the egg cocoons and hatch them under different temperatures or conditions and determine success rate, time of development etc.

ah yes.. I nearly forgot: bears and raccoons do like worms as well so unless you want to study these, I suggest you don’t leave your worm farm on your deck or close to the backdoor outside..

and above all publish! On the web! I for one will take it seriously…