In recent years, feral red-necked wallabies have been seen bobbing along dark stretches of road in Kent, scampering into towns in Devon, fighting police in St Ives, and patrolling the graves in London’s Highgate Cemetery.
But now, researchers at University College Dublin used public records and media reports to reveal there were almost 100 wallaby sightings in the UK over the past 10 years.
Free-range wallabies have been reported hopping all over the country, from Cornwall to Norfolk, and from the Home Counties all the way up to Scotland, though most were in the south.
So what are these pint-sized kangaroos doing on the wrong side of the planet, and should we be concerned about it?
Holly English, a PhD researcher at University College Dublin, who led the research said that red-necked wallabies have been in Britain for more than a century after first being imported from Australia for zoos and private collections.
However, during this time they have also proved to be highly competent escape artists, and there is even strong evidence the animals are now breeding in the wild.
Many were also intentionally released during the Second World War, when keepers’ priorities changed.
Speaking to The Independent Ms English said: “At the moment, we don't have any clear signs of negative effects of wallabies on native species, but this is probably because of their low numbers.”
But the research revealed wallabies are “more widely spread than we thought”, she added.
Dr Anthony Caravaggi, lecturer in Conservation Biology at the University of South Wales, who also worked on the research said: “It might come as a surprise that there have been so many sightings, but the fact is, wallabies are really good as escaping – they are fast, and able to leap some obstacles – so more of them end up roaming the British countryside than people might imagine. It’s possible that they’re breeding, too.
“In recent years they have become very popular not just with zoos and wildlife parks but with smaller petting farms and other tourist attractions.”
Writing in the journal Ecology and Evolution, the research team said a total of 95 confirmed wallaby sightings were recorded in the UK between 2008 and 2018, of which 64 came from media sources, 18 from Local Environmental Records Centres (LERCs), seven from the National Biodiversity Network (NBN), and six from academic sources.
“The greatest density of wallaby sightings was in southern England, with the Chiltern Hills Area of Outstanding Natural Beauty a particular hot spot,” the authors said.
Most of the records were of lone wallabies, but two of the sightings, in 2009 and 2010, were of female wallabies carrying young in their pouches, indicating the species was successfully breeding in the UK.
The researchers are hoping to conduct further research into the UK’s feral wallabies and collaborate with academics, ecologists and inhabitants of the areas of the UK where wallabies have been spotted to get more information about these unexpected settlers.
Q&A with lead author of the research, PhD researcher Holly English
Are wallaby numbers rising in the UK?
In the past, there was an established population of wallabies in the Peak District, which originated from released animals from a private collection around the time of World War II. This population was monitored but is thought to have gone extinct in 2009. Wallabies were also released on Inchconnachan, a small island in Loch Lomond in Scotland, in the 1940s and there are still wallabies there today. A study on Inchconnachan found 26 wallabies there in the mid-nineties but no one has surveyed them since. These known populations were studied previously, but our study is the first to look for reports of wallabies across all of Britain. So we really don't know if wallaby numbers are rising, but we have found their numbers are higher and more widely spread than we thought. And now we have a baseline to look for population increases or decreases in the future.
Are these free-roaming wallabies on course to become an established feral population in Britain?
We had two reports of female wallabies with joeys (young), so we have some tentative evidence that they might be breeding in the wild (outside Inchconnachan). Both of these records are from Cornwall and happened a year apart. It’s possible that the wallabies had bred before managing to escape from a captive collection, so we can't be completely sure if breeding in the wild is happening. But now we know where to look. While Cornwall had both records of joeys, the Chilterns Area of Outstanding Natural Beauty had the highest density of records, so this is a sensible place to survey in the future as well to look for signs of an establishing population.
What risks or benefits could they pose to the natural world in Britain?
At the moment, we don't have any clear signs of negative effects of wallabies on native species, but this is probably because of their low numbers. Wallabies are a big problem in New Zealand, where they are classed as an invasive species and harm native plants which evolved without any mammalian herbivore pressure. British plants have evolved in a system with grazing pressure, so should be more robust. That said muntjac deer are an invasive species in Britain which cause a lot of problems in woodland management and if wallaby numbers grow they could exacerbate this problem. There is also potential for wallabies to compete with hares.
Are they paving the way for a take over of the British Isles by kangaroos or other marsupials?
Hopefully not! Non-native species can have unexpected consequences for native ecosystems and no one should deliberately release an exotic species. Problematic invasive species in Britain include the grey squirrel (which spreads squirrel pox virus to red squirrels) and the previously mentioned muntjac deer (which impact tree regeneration in woodlands). We hope the wallaby will never become as problematic as these species but we should certainly keep an eye on their numbers and study potential impacts they might have.
The research is published in the journal Ecology and Evolution
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