Among his many profound achievements, Charles Darwin showed that earthworms are much brighter than they look. For example, they always drag leaves into their burrows by pulling them by their tips, the most mechanically efficient way of doing it. Not only that, Darwin cut a variety of leaf shapes from paper and offered them to the worms, thereby establishing that they know which end to choose - the narrowest - to draw them most easily into their holes.
Such insights shape the respect I feel for these fellow toilers in my garden, not to mention the truth of Gilbert White's observation that earth without its worms would soon become "cold, hardbound and void of fermentation and consequently sterile . . . " Digging over a neglected corner of the vegetable garden to fork out the roots of perennial weeds, I was conscious of wrecking the labyrinth of tunnels through which organic particles, water and air contribute to the earth's fertility. Each sprawling eviction of Lumbricus terrestris and its fellows was instantly regretted, and swiftly masked again with soil before the nearest robin could jump in.
What one thinks about when digging is mostly the digging itself, but the exaltation of a fine, calm day and sharp spring light bouncing off the sea did inspire something a bit wider that day. The word "bioturbation" popped up - what burrowing marine worms do across the vast floor of the ocean. They're not, of course, the only burrowers of seafloor sediments - there are mud shrimps, urchins, brittlestars and many more that dig away just as busily - but the bristle worms, the polychaetes, swallowing sediment at one end and squirting it out like toothpaste at the other, are stars at bioturbation.
Like earthworms ashore, they digest the sediment's organic particles and bacteria, and in the process recycle minerals and nutrients, bringing them up to the surface of the seabed in little mounds or ejected coils.
These then get stirred up by storms or upwellings of deep water to nourish phytoplankton in the great ocean blooms of spring. Sometimes, also, they stir up things that would be better left buried, as in the radionuclides accumulating off Sellafield.
The first deep digging I ever did was not in soil at all but in sands below the shingle beaches at Brighton, uncovered at low tide. Sandcastles, of course, came first, but later I joined a far more expert company, since there's considerable skill and brawn required in digging successfully for "lug" and "rag". Wielding a fork beside burly sea anglers was an education in itself. Lugworms and ragworms live in differently shaped burrows - even "blow lug" and "black lug" have their different behaviours - and each species demands its own digging technique if the worms are to be retrieved in one piece (the niceties are clearly described in the Book of Bait generously downloadable at www.sea-angling-ireland.org).
Lugworms, long (about 20cm), smooth and segmented polychaetes (bristle worms), are of the kind one doesn't mind handling. Anglers knew for generations that there were two kinds - the soft "blow lug", dug from the upper shore, and the much firmer and thus more desirable "black lug", living nearer the low-tide mark. They have differently-shaped burrows and leave differently-coiled casts of sand at the surface - but it took science until 1993 to decide that they were, indeed, separate species.
Beside these docile creatures, the ragworms - also species of bristle worms, or polychaetes - handle like agitated toothbrushes, and the "king rag", Nereis virens, is a spectacular creature up to 40cm long, a brilliant metallic turquoise with purple and yellow trimmings and with two pairs of eyes. Powerful toothed jaws at the business end are meant for chopping seaweed but can give your finger quite a painful nip.
I remember my awe when these writhing, exotic-looking animals were excavated from the Brighton sands. At their spawning, male and female ragworms, their bristles enlarged and broadened for swimming, leave the sea floor and swarm in moonlight just below the surface, shedding eggs and sperm before they die.
King rag are the choicest of bait worms (not least because they can be broken into bits that still wriggle on the hook). In Britain, where sea angling is estimated to use at least 1,000 tonnes of bait worms every year, the market for Nereis virens, dug from the wild or farmed in aquarium sediments enriched with brewers' yeast, is worth at least £8 million (€11.7 million).
The Atlantic strand below my hillside is too lacking in organic nourishment (no sewers) to support either lugworm or ragworm at any stage of the tide. I am left to brood on the vast diversity of the oceans' 37,000 species of worm: spoonworms, peanut worms, acorn worms, beard worms, peacock worms that put out those exquisite feather dusters, ribbon worms that can stretch to a threadlike 60m. . . the list goes on. All with a job to do, all of them to be eaten, low down on the food chain. Perhaps, as the sea rises, they will inherit your garden. We have a lovely wintering flock of 24 Whooper swans at Clogher Lough. Is the rusty colour around the head and upper neck a plumage colour or discolouration from muddy fields?
... Sean Lysaght,
Westport, Co Mayo
Iron stains from feeding sites in Iceland.
In a boggy area in the Mournes we came across a male grouse which ran away from us along the ground making no attempt to fly.
... Alan Watts,
Belfast
Grouse will first run away from encounters.
While walking on a beach of Blessington Lake, in a sheltered spot but just a few inches from the gravel beach, I came across a primrose in full flower. My wild flower book says the primrose flowers in March.
... David Nolan,
Santry, Dublin
We've noticed primroses and many of the primula family flowering almost all winter.
Eager egrets: reports of little egrets are coming from all over, even as far north as Donegal.