I often look out onto the garden and watch the bird life there, particuarly one or both of a pair of blackbirds who’ve nested a few yards away from me and by now must be on their second brood. Although the appetite of their chicks must be relatively enormous . . . , what I’ve noticed, though, is that their parents are not often on my lawn picking worms. They must be elsewhere, foraging in neighbours’ gardens. But some of them have blackbirds’ nests also. Thus it seems that food territories overlap. They can’t be quite the same as the nest territories that the birds defend every morning during the dawn chorus when all the birds are singing vociferously for minutes on end.
Sometimes there are three or four blackbirds feeding for worms simultanreously on my lawn. Whether they’re my blackbirds being joined by others or whether they are all foreign birds and mine are elsewhere I have no way of knowing, though I used to tell in my previous abode where the resident garden blackbird (for a year or two anyway) had a white patch on its head — a rare genetic mishap but which, it seemed, didn’t seem to do him, or her, any bother. He (or she) seemed as perky as normal and appeared well fed.
But when a bird is on my lawn, I’ve noticed that it pecks at one spot then moves a few feet away to another spot and then to another a few feet away and then to another and so on in a random way. And, besides, it doesn’t stay long on my lawn before flying away even though it seems to be succcessful. Why don’t the pair of my resident birds work the lawn in their own backyard, as it were? It would save them an awful lot of energy flying around the neighbourhood. Why don’t they systematically work their way along foot by foot?
And then I began thinking about moles. From their underground family homes they send tunnels in all directions. Why don’t they drill their tunnels systematically in parallel lines? They could leave their base in the morning and work their way along one tunnel and then back home along a parallel one picking up worms along the way. If they haven’t had enough breakfast, they could go away along another parallel tunnel and then abck hone again. None of the moles in that particular family would never need to tunnel or to travel far if they did the parallel thing.
A llittle reflection suggested the reason why not. Natural predators of moles would soon teig what the moles were up to. The regular array of mole hills would give the game away. If therefore an owl or a kestrel kept an eye on where the next mole hill was likely to appear the chances would be quite high that a mole would be momentarily available above ground. No, parallel tunnelling wouldn’t be a good strategy for moles.
But this doesn’t explain why both moles and blackbirds are into random foraging — or as it bhighly likely all foraging animals. Why don’t they harvest their food systematically as modern farmer-man does? Actually farmers in Europe didn’t catch on to sowing grain seed in straight rows until about 1400 — ti was random broadcast sowing previously — until the novel idea had finally permeating through to them from China via the Silk Road, where Chinee farmers they had been sowing seeds in straight lines for 2,000 years.
The only explanation I can come up with is that if moles and blackbirds (and an occasional green woodpecker who visits my lawn for ants) do their foraging in a rather slapdash random manner it is because they then avoid what the modern farmer cannot avoid — systematic diminishment of the soil’s fertility. Farmers have to replenish their soil every year with fertilizers to replace what they’ve taken away from the soil in the previous hyear. If my resident pair of blackbirds systematically deprived my lawn of worms then not only would the drainage of my (and their) lawn suffer from lack of worm holes but also the natural micro-ecology of the soil — all those other forms of bacterial, fungal and insect life — might be badly affected and might not attract worms again. Once my lawn was exhausgged of worrms, it might stay exhausted.
In fact, I remembered that when I first moved here, half of what passed for a lawn was totally and permanently waterlogged and there were no worms there at all. Whatever mysterious ecological events were going on in that part of the subterranean ecology was certainly a great deal different from what I consider to be normal soil. In fact, I had to dig over that area pretty thoroughly and add a few cubic yards of sand and soil before i persuaded even a blade of grass grow there — and, no doubt, for worms to move in from the healthier areas and do their stuff again. And, of course, the same applies to moles. If they were as clever as we were then then they’d queer their own patch. They wouldn’t have workable, burrowable soil any longer.
And then I fell to wondering a bit more about those clever Chinese who planted their grain seed in straight rows 2,000 years ago. In fact, they planted their millet seed so throughly in the rich yellow loess soils in north-western China that large regions of it are now desert. On many days of the year, thousands of tons of dust are blown eastwards into Beijing and other cities producing yellow mists so thick sometimes that it can becone a traffic hazard. It was a constant embarrassment to the Chinese government when it realised, rather late in their plans, that it might have adversely affect the Olympic Games when held there iin 2008.
Fortunately it didn’t. In fact, this and many other matters, prticularly to do with coal, have begun to make good environmenttalists of the Chinese. They have now begin to plant thick bands of forests in crucial areas of the inland where there used to be productive — actually overproductive — farms for centuries. Gradually, they hope, they will stop the dust storms and push the desert back and stablise the soils in those regions.
And now, reflecting even further to my previous post about Africa, perhaps this is something that the EU could usefully do for Africa by setting to work helping Africans to replensh the man-made desert we call the Sahara. This is entirely feasible according to some Israeli agricultural experts — who are the world leaders in such restoritative schemes — if the job were done on a sufficient sacle. It would be a project that would take a lot of funding and probably a few centuries to achieve. But it would also, as a couple of bonuses, give a lot of jobs to Africans and also the new vegetation would probably soak up a great deal of the man-made carbon dioxide in the atmosphere that the EU Commissioners, more than anybody else, are so worried about. Why not re-make the Sahara, not as a place for passing through as Africans have to (and not a few Middle Easterners also) on their way to Libya, but as region offering plentiful useful work? There are crazier ideas than this.