IT’S MINUS 13°C in Fargo, North Dakota, and I’m talking to a woman about tropical . Page Klug, a biologist at the National Wildlife Research Center’s (NWRC) field station there, has recently taken a keen interest in the squawky invaders. Not, she stresses, because they have got as far as North Dakota – not yet, anyway. But because she is a leading researcher on agricultural pests of the avian variety and her expertise is in demand.
To Londoners like me, this will come as no surprise. When I moved to that city three decades ago, ring-necked parakeets were a rarity, an occasional raucous flash of green in a park. These days it is a rare walk through the urban jungle that doesn’t feature an encounter, and the city is now as famous for its parakeets as for its pigeons. “The population has really taken off,” says Tim Blackburn, a biologist at University College London. “Pretty much anywhere you go in London you can’t miss them, and they’re obviously spreading very rapidly.”
What is happening in my backyard turns out to be happening all over the world. A decade ago, it was mostly a European problem. Now, more than 35 countries, from the US to Israel and most recently Azerbaijan, are experiencing an explosion in their populations of alien parakeets. This makes these birds among the and, like other invaders, they are increasingly making a nuisance of themselves. How did these showy creatures from the tropics spread so far and wide? What does their success tell us about the world we are creating? And can anything be done about them?
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Even before it started its world tour, the range of the ring-necked parakeet (Psittacus krameri, also known as the rose-ringed parakeet) was extensive. When first , the species inhabited a band right across sub-Saharan Africa, from Gambia to the Horn of Africa. In the early 20th century, a separate subspecies, Psittacus krameri borealis, was described living on the Indian subcontinent. It is this population from which the European parakeets are descended, according to genetic evidence.
They probably arrived as pets. In the UK, the first recorded sightings in the wild were in Norfolk in 1855, but the birds don’t seem to have survived for long. A breeding pair with five offspring was reported living in a tree in Lincoln’s Inn Fields in central London in 1886, but again didn’t persist. The first long-term wild populations were established in Kent in the late 1960s, and by the 1970s there were small colonies in counties around London. The first northern populations were established in Greater Manchester around this time too. Now, parakeets can be found in Scotland and there have been a few sightings in Wales, but they have yet to make it to Ireland.
There is no shortage of colourful stories about how they got here. Some involve Hollywood goddesses, rock gods or even acts of god, but all are almost certainly apocryphal (see “Just so stories”). The prosaic truth is that there was no single founding population. The birds probably escaped – or were released – from captivity in dribs and drabs over many years. Parakeets are expert escapologists and break out of cages and aviaries all the time, says Richard Bufton at the University of Birmingham, UK, who researches their spread.
The population remained in the low hundreds until about 1986, then exploded. The most recent census, from 2012, put the number of breeding pairs in the UK at 8600. “It’s likely to be a lot more now,” says Bufton. He maintains a register of sightings and reckons there are about 30,000 individuals across the country, which officially makes the ring-necked parakeet a . What’s more, numbers now appear to be rising by about 30 per cent a year.
Exactly what caused the upswing isn’t clear. “I suspect it’s partly a natural stage of population growth,” says Blackburn. “Populations often bounce along at relatively low levels, then reach a point at which they grow much more quickly.” It may be that a recent escapee introduced new genes into the population, which increased individuals’ chances of survival in their new environment.
Perhaps this was an adaptation to the cold. Blackburn points out that ring-necked parakeets live quite happily in the foothills of the Himalayas, so must already be adapted to cold to some extent. But not fully. “You often see them with missing toes as a results of frostbite,” says Bufton. He thinks that parakeets exploit the urban heat island effect to cling on through the winter months, which in the UK means living in or near cities. The most northerly outpost they have conquered in the world so far is Glasgow. The recent arrivals in Baku, Azerbaijan – where midwinter temperatures hover around freezing – appear to survive by roosting near oil refineries that burn waste gas.
For now, invasive parakeets are considered synanthropic, meaning that they live in close proximity to humans so as to exploit artificial habitats such as heat islands and bird feeders. But climate change could alter that. “My suspicion is that as the climate generally warms, and particularly as winters get milder, there are probably more birds making it through the winter and that’s helping the population to grow,” says Blackburn. “Increasingly, I think we’ll see them outside the cities.” They will probably spread even further north. So, there may yet be life in Monty Python’s parrot – there is a blue variety of ring-necked parakeet.
Their further spread is an intriguing prospect, but no joke. “Alien species are one of the primary ways that humans are changing the natural world,” says Blackburn. “Understanding that invasion process is very important for understanding environmental risks humans are posing.”
“With 30,000 parakeets in the UK, they are officially a common bird there now”
In the US, parakeets have already expanded beyond cities: southern states, including Alabama, California, Florida, Louisiana, Texas and Virginia, have . And they are increasingly troublesome. “They have the capability of becoming serious agricultural pests,” says Klug. The birds naturally eat fruit, so flock to fruit trees, but they also devour nut and seed crops. They are destructive, wasteful eaters. “They’ll pick something up, give it a peck, ruin it for sale, but then drop it and move on to something else,” says Jim Groombridge at the University of Kent, UK.
, but there is growing concern that expanding parakeet populations are putting a squeeze on native wildlife. Invasive species are one of the leading causes of biodiversity loss, and parakeets compete with other species in several ways. For a start, they nest in tree hollows. “They occupy nest sites much earlier than British birds do,” says Bufton. That can leave birds that nest in tree holes, like nuthatches and woodpeckers, with nowhere to go. “This is one of the reasons why they are so successful,” he says. “There’s also some evidence that they push certain native species off bird feeders and therefore potentially have impact through competition for food,” says Blackburn. In southern Spain, meanwhile, the parakeets are , Europe’s largest bat, which is classified as vulnerable to extinction. The birds usurp its nesting holes in trees and sometimes peck the bats to death.
There is also a growing realisation that parakeets can be a reservoir of pathogens. They carry some diseases found in livestock, although there is no evidence that they pass these on to them, says Blackburn. However, pet parakeets do sometimes transmit a flu-like infection called ; an outbreak of this “parrot fever” in France in 1930 apparently caused some owners to release their birds into the wild, which has been proposed as the origin of the European population.
Noise pollution
Another growing problem is the squawking. Parakeets are noisy birds and when they mass together in roosts they can be cacophonous. There are anecdotal reports of people being kept awake at night or being unable to sell their houses because of parakeet noise pollution, says Groombridge.
If you want to see the damage parakeets can do, look to Hawaii. Ring-necks arrived on Oahu island in the 1930s and found the conditions to their liking. For years they were little more than a curiosity, but now they are becoming a serious pest. “Parakeet populations can have these really long lag times where they’re not a problem. Then numbers start to increase exponentially,” says Klug. This is what has happened in Hawaii in the past two decades. By 2018, there were approximately and a further 6800 on Kauai. “They are really starting to show an impact on agriculture and tourist resorts, with their faecal and noise pollution,” she says. Many people have had enough. “I think that the level of damage has reached a point that there is support for controlling that population,” says Klug.
Eradicating Hawaii’s parakeets wouldn’t be easy, though. There are essentially two options: the gun or the pill. Shooting is quick and deadly but hard to do safely when there are people and other animals around. Contraceptive-laced bait has proven effective in the lab, but is difficult to roll out in the wild, as you have to design feeders that are accessible only to your target species. Even then, parakeets are long-lived, so a contraceptive-led eradication programme may take 20 to 30 years. And there is a fear that a control programme could make things worse by driving parakeets out of the agricultural lowlands and into the highlands, where they could pose a threat to Hawaii’s endangered native birds. “They can be aggressive, so there’s a conservation component that we’re concerned about,” says Klug.
“At this point, with the numbers that there are, the effort is going to have to be long and sustained to be able to even bring their populations down,” says Klug. However, there is a precedent. Last year, Seychelles announced the from its main island, Mahe, after an . The last of around 500 birds was shot in 2017 and none have been seen since then. “It’s the one successful campaign,” says Klug.
As yet, there is little appetite for parakeet eradication outside Hawaii and Seychelles. Nevertheless, biologists are beginning to advocate control programmes in some areas where the bird isn’t yet a pest. California, for example, with its almond, pistachio and fruit farms, is considered especially vulnerable to invasive parakeets. In a recent , Klug’s colleague Aaron Shiels at the NWRC field station at Fort Collins, Colorado, argued that California should consider controlling parakeets while it still can.
In Europe – and especially in Britain – that probably isn’t an option. The genie is already out of the bottle; parakeets are just too abundant and spreading too fast to control. “I suspect as time goes on, we will wish we’d done something about them 40 years ago,” says Bufton. “I think the time for eradicating them is long gone.” Besides, killing parakeets would be controversial. “A lot of people love them. I love them. I think they are awesome birds,” he says.
But sentiment can turn. “Many people love seeing them in their gardens,” says Groombridge. “But once they hit a certain threshold, where suddenly all you’re seeing is parrots in your garden… It’s interesting how people’s perceptions change.” If familiarity breeds contempt then, like London’s maligned pigeons, parakeets may one day be regarded as flying rats.
Even if ring-necked parakeets were to go the way of the dodo, that wouldn’t necessarily end Europe’s parrot problem. There are many similar species that could take their place. The monk parakeet – a cold-adapted native of South America – is already out of control in some cities, including Barcelona in Spain. The from India – which looks just like the ring-necked but with a purple patch on its shoulder – is already in the UK, Belgium, Germany and Italy.
“There are about a dozen, if not more, parrot species that have breeding populations in Europe and which are classed as potentially invasive,” says Groombridge. “They’re waiting in the wings.”
Just so stories
Tales of how ring-necked parakeets arrived in the UK are often as colourful and raucous as the birds themselves. One widely parroted yarn is that they escaped from the set of the Katharine Hepburn movie The African Queen, parts of which were filmed at in west London in 1951. Another is that Jimi Hendrix released a pair on Carnaby Street in London in 1968 or thereabouts. A third is a mass escape, perhaps from an animal pound at Heathrow Airport or an aviary that had its roof blown off during the Great Storm of 1987.
These things may have happened, but claims that any were the original source of parakeets in the UK have been dismissed as urban myths. “They’re not the answer,” says Sally Faulkner at Queen Mary University of London. She and her colleagues recently used a technique from criminology called geographical profiling to analyse the spatial distribution of the birds from the 1960s onwards. It revealed that , over a long period of time.
Other origin stories are equally dubious. The population in Brussels, Belgium, for example, was supposedly started in 1974 when a zookeeper released a flock to brighten up the city. It’s a nice idea. However, the first recorded sighting there dates back to 1966.
