Terry O'Connor

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Swamped by migrants?

A short piece by Tom Bawden in today’s i newspaper raises an alarming picture of ‘alien’ bird species moving into Britain as part of a global process of species moving beyond their native range through trade, colonialism and climate change. The article is headed “Alien birds ‘are a threat’ to native species” and is apparently based on a new paper on the subject in PLoS Biology. A shorter version of the i article is available on-line here. The newspaper article begins by talking up the situation in the UK, specifically naming ring-neck (sic) parakeets, little owls and golden pheasants as alien introductions to Britain, then ends by quoting the senior author of the paper, Prof Tim Blackburn, “It’s a worry because aliens may threaten the survival of native species”. A newspaper reader unfamiliar with the subject and unable to access the PLoS Biology paper would easily conclude that alien birds introduced to the UK may be a threat to native bird species, a conclusion reinforced by the accompanying picture of parakeets captioned “…among many foreign species that have settled in Britain”.

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Evil Alien Ring-Necked Parakeet. Source: http://birdingfrontiers.com/2013/02/20/ring-necked-parakeet

Now just a minute. It is true that the worldwide rate of introduction has risen in recent years, not least because of the global movement of people and their travel experience. The PLoS Biology paper is a detailed and informative review of the processes involved and of the variables that make initial introduction and subsequent establishment of alien populations most likely to occur. The authors make the point that moist temperate regions that have high native species richness are likely to have high alien species richness: introduced birds will establish most successfully where conditions are good for birds. Environmental factors such as climate and topography have little effect on the probability of introduction, which is more likely a factor of trade and colonial history, but certainly affect the probability of a population successfully establishing. On that point, the paper concludes that about 420 introductions out of 1000 around the world have established successfully: in other words, a minority. The important point is that the research paper discusses alien bird populations as a global issue, while the presentation in the newspaper makes it seem as if these alien species are a threat to our precious ‘native’ wildlife.

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Blackbird. But this one  is in New Zealand, so it is a pestilential alien. Source: http://www.nigel-roberts.info/bird-photography.htm

A few years back when I was researching my Animals as Neighbors book, I took a good look at the evidence for ring-necked parakeets detrimentally affecting native bird populations in Western Europe. There was quite a bit of anecdotal chat, to the effect that parakeets will arrive mob-handed at a suburban bird-table, causing other birds to back off and to stop feeding. No doubt that happens, as it does in my garden when a gang of greenfinches comes muscling in. After a while they go away and the other birds resume feeding. The more systematic research found little evidence that ring-necked parakeets were having a significant impact on native species in terms of food or nesting space. As for the other two species named in the i article, little owls have been in Britain since the mid-1800s and so have had plenty of time to wreak havoc on our wildlife, which they have conspicuously failed to do. Maybe that is why they always have that irritated expression on their little faces? As for golden pheasants, Lever’s The Naturalised Animals of Britain and Ireland reckons they arrived in Britain around 1725. In the intervening three centuries, their UK population peaked at between 1000 and 2000 and now seems to be declining.

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Little owl, looking typically cheesed off. Source: http://imgarcade/1/little-owl

The newspaper article really annoyed me (go on, you guessed that didn’t you?) for a number of reasons. It did little credit to its source, a useful and thorough research paper that deserved better, and it added to an insidious undercurrent of ‘nativism’ in UK natural history narratives that is just too close to the current anti-migrant miasma in politics and the printed media. If that seems a little fanciful, bear in mind that one of the threads that contributed to the emergence of nature conservation in the early 20th century was a right-wing nativism that subsequently influenced the Nazi obsession with the pure German Volk and Land. “British peanuts for British birds” is an echo of “British jobs for British workers”.

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Present-day use of ‘nature’ imagery by Danish neo-Nazi Povl Heinrich Riis-Knudsen

The concern about alien birds is also a distraction. The loss of species and drastic reduction in populations of some other species in the UK is not because of parakeets and little owls. It is because of habitat destruction directly, as hedgerows and overgrown headlands have been destroyed, and indirectly as pesticides and intensive crop management have reduced the insect populations on which many species depend. Add to that the deliberate killing of birds on shooting estates and it is clear that the UK is quite capable of impacting its native birds without the help of alien species. What is an alien, anyway? When I was a small boy, collared doves were just getting a foothold in the south-east of England. Now they are routinely seen everywhere, even in the Shetland Islands. Over the last 20 years, little egrets have colonised wetlands in England, reaching as far north as Yorkshire. I have yet to hear anyone sounding the alarm that they may be competing for food with ‘our’ native grey herons, though they probably are. Human activity is affecting bird populations for better and (mostly) for worse all over the world. Personally, I am quite happy to see ‘alien’ birds establishing free-living populations in Britain: ring-necked parakeets are bright, cheerful birds and little egrets have a certain Art Deco elegance. We should stop obsessing about what is native and what is not, stop using it as a distraction from admitting that too many bird species are in significant trouble, and just accept that in times of global environmental change, regional faunal turnover is simply going to happen.

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Little egret, casually looking elegant. Source: http://www.arthurgrosset.com/europebirds/little%20egret.html

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