Every day now, for a couple of weeks, I have taken a pole to a young spruce tree beside the house and vandalised the nest the magpies are trying to build there. I push and shove and rattle around until all the big twigs and lumps of mud have showered to the ground, then lean on the pole, an exhausted gondolier.
"I think they've got the message this time," I say - or have stopped saying, as one or other of the birds flies in yet again with a replacement girder twice as long as itself. "They haven't gone away, you know" could have been coined for magpies.
This springtime battle of wills has been running for 20 years, on and off. When we came to the acre, its solitary tree was the old spruce at the gate, regularly shredded by storms. The magpie nest filling its crown was so robust and well-cemented that lammergeiers could have lodged there. It took many seasons, and persistent evictions with a beachcombed 12-foot bamboo salmon-gaff, to break the tenancy.
Now we have trees of many kinds, not all of them in the right places. The young spruce in question has grown up beyond one of the living-room windows, right between the mountain and my corner of the sofa. Eventually, it will have to go, but, in the meantime, I cannot have magpies going about their clattering, piratical routines while I am trying to watch the early-evening nature films on television.
Some double standards here, do you think? Suppose it wasn't magpies but merlins or sparrowhawks: wouldn't I be thrilled ? "Oh look, he's got a pipit!" Hawks are photogenic, made for the long lens, eyes agleam and beaks a-curving, while magpies are thuggish, clumsy, beautiful on occasion but, above all, raucously self-advertising.
What magpies actually feed to their nestlings is mostly invertebrates - beetles, caterpillars, and so on - with a bit of dead sheep if they can find it. It's the other 20 per cent - the thrush's eggs, the robin's nestlings - that sticks, so to speak, in the craw.
Their tree - well, not their tree, if I can help it - overlooks The Hollow, full of little songbirds. That awful rattling as they raid, wings sprawled across the branches: it's like watching rape.
On the other hand (the naturalist speaking), the acre is now a perfect magpie territory, a little maze of copses and clearings, ringing with birdsong at dawn, and surrounded by pastures full of sheep. Just now, the first lambs are shining in the green, like swans or mushrooms, and the electric bird-scarers set off random ambushes of bangs. That may work with the great blackbacked gulls, but magpies, I suspect, are better at counting, and dash in to claim their share of afterbirth, if not actual entrails or eyeballs.
Even having a house on the acre suits them very well, because tolerance of human activity is the one edge they have over their arch-enemies and competitors, the hooded crows. Nesting right beside houses is actually a choice they make, especially in relatively treeless rural areas where good nesting sites are scarce.
For some years, a pair has nested in conifers at the first house down the boreen and it is from their offspring, probably, that our pair has come. Most young magpies try to set up a territory close to home, and the increasing leafiness of our acre, with its rising songbird population, was obviously attractive. In any farmland valley reasonably furnished with trees, the breeding density of magpies can reach about 30 pairs in each square kilometre before it stabilises.
Hoodies have often prospected the "vacant" tree at the gate. Indeed, a few springs ago they started building, but a few expostulations from the lawn (the bamboo having fallen apart) were enough to discourage them: they came back, in relays, to retrieve their twigs. Predators are part of the natural picture, and of course we accept them - but not, as it were, in our emotional back-yard, and with such dreadful table manners and noisy lack of discretion. If the magpies like to move to the really quite desirable clump of conifers half-way down the acre, they can stay.
Meanwhile, the daily confrontation continues. It could go on, indeed, for 40 days or more of the nest-construction impulse. Both birds are at work, ferrying twigs from our enormous pile of brushwood and lumps of mud dug out from the banks of the stream. The male (a bit larger) does most of the heavy carrying, while his mate does more of the arranging. I try not to watch too much: it makes it harder to be an unfeeling bastard.
For those with only cuddly robins to be concerned with, there is still time to help Gavin Fennessy, down in UCC, with his robin nest and habitat study, run as part of his PhD research.
He began this last spring, recruiting participants all over Ireland, and ended up with the monitoring of more than 200 nests. His watchers recorded details on a card about the nest itself and about the number of eggs and nestlings, the amount of predation, and so on. Much has already been learned about the nesting habits of Irish robins: they are much more common in Ireland than in Britain, but seem for example, to lay significantly fewer eggs.
The more observations, the more reliable and interesting the findings are likely to be. Gavin Fennessy is at the Zoology and Animal Ecology Department, University College Cork, Lee Maltings, Prospect Row, Cork, phone 021-904283; e-mail: sczo6106@bureau.ucc.ie.