During a birdwatching lull, after each of us had borrowed the best-looking tripod for a closer look at some marsh herons, the subject turned to the explosive issue of the ruddy duck. Being among friends, some of the company confessed that they were shooting the ducks on the quiet. Although they were introduced into this country during the 1950s, the ruddy ducks never really assimilated. They just bred and bred and made themselves a nuisance. No one used the expression "River Tiber foaming with much blood" but the tension in the twitching community was evident.
Now it has burst into the open with the row over the British parakeets, which have been downgraded to pigeon status, meaning you can reach for your shotgun. The London Wildlife Trust, fearing that a kind of ethnic cleansing will follow, has issued a statement celebrating "London's cultural and historical diversity" and urging Londoners to regard parakeets as being "as British as curry". Nigel, from London, writes on the Evening Standard website: "I wonder how many of these immigrant-bird haters are also paid-up members of the BNP."
The question of whether parakeets stand as a metaphor for racial integration in Britain demands some soul- searching. I look guiltily at my book of British birds with its firm categories: "summer visitors, passage migrants, winter visitors and British residents". It is a beauty of the bird world that it is without borders. Birds come and go as they please. Could this not be an inspiration for our immigration policy? See how many of the foreign workers that we feared would overwhelm us have left now that the jobs have dried up. They were passage migrants after all.
The trouble starts when passage migrants decide to become British residents. How can we ensure there is an enhancing fusion of cultures rather than reverse colonialism? My irritation with the parakeets in Richmond Park is that they have displaced the native birds. There is an aesthetic objection to this. The colours of the British landscape tend to be muddy. Our birds are plain-looking, except for thrilling flashes of colour. The blue tit and the robin and the rarer bullfinch are about as bright as it gets. I cannot see the thrushes or the sparrows and starlings in Richmond Park any more. The trees look as if they belong to St Lucia, and the noise reaches carnival levels.
The origins of the parakeets in this country are veiled in folklore. Did they breed from an original pair brought by Jimi Hendrix? Did they escape from a container at Heathrow during the filming of African Queen in 1951? Two parakeets are a curiosity, 44,000 are an invasion.
Should we just accept the survival of the breeding species? It is fogeyish to forever mourn the passing of the red squirrel and the triumph of the grey. The interesting fact about British birds is that only a tiny number are truly native. We, more than many countries, act as air traffic controllers for global routes. So why should we suddenly decide on draconian measures against parakeets?
I have examined my liberal conscience, and I can say with conviction to Nigel from London that you can be anti-parakeet without being pro-BNP. Because birds are not people. There is a balance of nature in Britain. We lose it when we cover the fields with bright yellow rape, which does not suit the surroundings. We forfeit it when London becomes plagued by scrawny, diseased foxes. And we should not surrender Wordsworthian countryside to parakeets. I want to see bright people, in muted landscapes.