Tuesday, 14 November 2017


Permanent Leave to Remain 

There are many species that have arrived and thrived in the UK. Becoming commonly sighted in many parts of the country and starting cautiously, in most cases, down the well travelled road of the Eastern Grey Squirrel, (the most common species of Squirrel in Britain, out-competing and almost extinguishing our native species, The Red Squirrel, which now only exists in protected pockets of land around the country.) These soon to become residents, are not yet citizens at this point in their dispersion throughout our green land of grey skies and tree-ringed parks; but certainly have been granted 'permanent leave to remain', application for citizenship pending.

Many of these invasive species probably started with a few specimens which had escaped from local zoos and wildlife parks or in some cases were intentionally released into the wild by private owners. As a  rule of settlement, if you have enough individuals released into an area in which the habitat is suitable or survivable, then a breeding population is possible. In myriad cases, this seems to be what has been taking place and the 'alleged' warmer climate has made the proliferation of these infiltrators possible.

The following list is not meant to be exhaustive but seeks only to demonstrate some notable examples of 'naturalised' exotic animals that are currently flourishing in our wild places:

Wallaby spotted by mother and son, Lucy and Josh Austin
In Bethersden, Kent. March 2017 
There is a healthy wallaby population living in Staffordshire that originated from five individuals that escaped from a private zoo during World War II. Buckinghamshire, Oxfordshire The Peak District, East Sussex, West Sussex, Hampshire, Lancashire, Cambridge and Cornwall also have sustainable numbers of wallabies, some of which are thought to date back to the 1900s. There are long established populations in Scotland dating back to the 1970s and also a group on the Isle of Man that are descended from 1 pair that escaped from a wildlife park. Wallabies co-exist well with other native species and would definitely fit neatly into the category of becoming a native species within the next 50 years.

The Coypu or “swamp beaver” is a very adaptable species of rodent from South America. Farmed in Britain for fur, escapees or 'fur trade survivors', adapted to our riverbank and streams with ease. The animal was officially eradicated in 1987 but it is believed that there is a small and growing population still extant in Norfolk.

Beaver: Quite recently a dog walker in Devon spotted the first wild beaver that has lived in England for over 800 years. While Scotland saw a successful reintroduction in 2009 via a five-year ecological trial, which to my knowledge is still going strong, with reported sightings and beaver sign being seen as far south as Manchester. Beavers were hunted to extinction in Britain in the 13th Century, being prized for their fur and scent glands.

Wild Boar - Wild Boar seem to be spreading across the country rapidly, two hundred wild boars can be found inhabiting Kent, and East Sussex. A further fifteen hundred in Herefordshire and Gloucestershire and 100 animals in Dartmoor, Devon as well as 50 individuals in West Dorset. The male of the species can exceed 20 stone when fully grown, is aggressive if cornered or approached and is not afraid of humans. Their reestablishment, albeit in small pockets of the countryside embodies a most unwelcome return of a rather unpleasant and dangerous animal.

Chinese Mitten Crab
The Chinese Mitten Crab or Moon Crab inhabits tidal streams, rivers and estuaries. First recorded in the River Thames in 1935, it is now endemic in the rivers Thames, Humber, Medway, Tyne, Wharfe and Ouse. Adults migrate down rivers in the autumn to gather in estuaries to breed and can also cross dry land. Some specimens have even been found in in freshwater ponds, far from the sea. The ability of this species to travel large distances up river systems makes the threat of its nationwide spread, significant.

American Mink 
Native to North America this animal has had one of the most significant impacts on British Wildlife, especially vulnerable to this species are water voles, seabirds, domestic fowl and fish. Mostly nocturnal, it is usually found near rivers and lakes and occasionally in a coastal setting. The species was introduced in the 1920s for fur farming and quickly became established following numerous escapes. It is also suspected that there may have been several deliberate introductions of the species into the wild in order to establish a natural population from which to obtain our products. it is currently an offence to release or allow the escape of these animals into the British countryside.

Canada Goose 
This next animal on this list is one I was surprised to find to be non-indigenous to the UK. First introduced from North America as an ornamental bird in the 17th century the Canada Goose, like the Eastern (Grey) Squirrel, is a species so established in Britain, that it has become a natural part of the local fauna and no more out of place in our rivers, lakes and ponds than a swan or  mallard. The flocking and feeding habits of this bird are damaging to crops and grasslands and they are known to have a detrimental effect on riverbanks and on the nests of native species.

It is currently believed that there are just a few of these North American mammals roaming wild here. The animals have been spotted in Hampshire, Leicestershire, County Durham and West Berkshire. Although cute and 'cuddly' as babies, racoons become very aggressive upon reaching sexual maturity, which often results in them being dumped by their owners. Although they are not thought to be an established species in the UK at present, it is admitted and feared that a few breeding pairs could lead to a population outbreak in a matter of years. Voracious predators and scavengers, they are considered to be a pest, Their colonisation of Britain would have severe ramifications for many native species. It has been illegal to keep a racoon without a licence, since 2007.

By Brocken Inaglory
Eagle Owl 
A large and intimidating owl, with dark orange eyes, long ear tufts and brown plumage. Standing at 70 cm with a wingspan of 2 metres it is an impressive creature and not one likely to be easily mistaken for another. Kept in captivity since the 18th century, the species has regularly escaped in the UK, but at present, there are only a few breeding pairs, most of which mainly inhabit northern England. If eagle owls were to spread in the UK, then some native species of birds of prey would suffer due to increased competition for food. The eagle owl is also very aggressive to humans and dogs near its nesting site and could inflict serious injury on pets and children.

Xenopus Toad 
The Xenopus Toad or African Clawed Toad is found in lowland ponds in Sub Saharan Africa. They have brown-grey mottled bodies with white undersides, powerful hind legs with webbed clawed feet, small front legs with splayed long fingers and small eyes. They are primarily aquatic although they can move across land to colonise other ponds. Their diet consists of water-fleas and terrestrial invertebrates. Populations have been found in Kent, the Isle of Wight and South Wales. As a child growing up in South Wales, I had two Xenopus toads as pets for several years and could not have imagined then that there may have been, homegrown members of this species, existing naturally in the wild, in ponds and rivers somewhere nearby. The species can live up to 14 years in the wild. Populations may have been introduced as pets released into the wild or escaped from laboratories.

Rose Ringed Parakeet
If you live in or have ever visited some of the lovely towns and villages in Surrey, you will be familiar with this noisy, yet pretty bird. First introduced in the 19th century, but not firmly established until the early 70's it is a large all-green parakeet with a bright red bill and long tapering tail. There are estimated to be 50,000 Rose Ringed Parakeets in Greater London and Surrey, thousands of which reside in the capital.

Sika Deer
Sika deer were first introduced into Britain in 1860, later, several escapes from wildlife parks and private holdings led to them becoming established in many areas in the UK. The main populations are located in Scotland, Devon, Lancashire and Cumbria. Because Sika deer can hybridise with red deer, they pose an emerging conservation threat to native red deer which could incrementally be bred out of existence over time. An example of this can be found in Scotland where most of the Sika deer population are hybrids. The most common type of Sika deer in the UK is the Japanese subspecies which is significantly smaller than the Manchurian subspecies. a high population of Sika can have a detrimental impact on woodland vegetation and ground flora and poses a threat to road users through collision.

Western Green Lizard
There have been countless introductions of this lizard in the UK since the late 1800s, with populations existing in North Wales, Devon, Kent, Surrey, Bournemouth and Dorset. This lizard is much larger than native species and non-native lizards found in the UK and can reach 30-40 cm in length. It is green with a white or pale yellow underside and may pose a hazard to native lizards upon which it feeds along with invertebrates.

Most adults of my generation can remember having one of these cute creatures as a pet sometime during their childhood, or if not so lucky as to have owned one, would surely have known a friend who did. Many Terrapins were bought at the height of the Teenage Mutant Ninja Turtles craze in the late 80s, and later dumped in our ponds, lakes and reservoirs when they grew too large. Many Individuals can be seen basking on lake islands in both Cardiff and London lakes. Terrapins can live for up to 40 years and happily adapt to our climate. There have been several campaigns over the years to capture red-eared terrapins from our waterways, but the creatures seem to be present in sufficient numbers to absorb a dip in their population. conservationists fear the reptiles, which eat a varied diet of insects, fish, amphibians and even small waterfowl, could have a lasting effect on local ecosystems. it is not known whether the creatures are successfully breeding or whether we are seeing a surviving relict population from the first Teenage Mutant Ninja Turtles film in the '80s. Of course with the recent remake of the film in 2014, we could be seeing further releases of new terrapins for years to come!

There are thought to be around 10,000 yellow-tailed scorpions living in the walls of Sheerness Docks, Kent. These venomous creatures have been residing in Sheerness docks for over 200 years, since first arriving in Britain in the early 1800s. Although the yellow-tailed scorpion has a sting, similarly to bee stings, it can only kill a human if they happen to be allergic. These fearsome looking arachnids are insectivorous and feed on woodlice and other insects and are known to be cannibalistic when living in large colonies. There are reported to be other colonies of these scorpions living in Harwich docks, Pinner, Tilbury docks, Portsmouth docks and Southampton docks. It is not thought that they have the potential to spread throughout the country and throughout their 200-year history in Britain, they have rarely been seen away from their dockland enclaves.

Licensed to Kill
There are of also many exotic and dangerous wild animals kept by private owners under the 'Dangerous Wild Animals Actresiding behind closed doors and reinforced steel cages here in the UK. But, these beasts are known, at least to the local authorities and as can be seen from the recent numbers below, accessed from a freedom of information act, put forward by a national newspaper to ascertain their whereabouts; and in the meanwhile putting both the owners and their animals at risk of poachers and thieves; the interest and passion for keeping and caring for exotic animals in Britain is still going strong!
What the future of these animals holds in regards to the fidelity of their housing is concerned, no-one can know. What is clear, is that the bulk of invasive species in the UK and those random exotic individuals that are occasionally sighted are former captives, beloved pets or wildlife attractions that slipped away one day or were set free, never to be seen again by their owners and free to thrive or survive in an ever-dwindling land.

These deadly menageries can be found in several major cities, including London, Swansea, Stoke, Sheffield, Hull, Portsmouth and Cornwall. Dangerous Wild Animal licences, which allow people to keep these deadly creatures as pets (as long as they have safety measures in place and pay a fee), have been issued for 3 tigers, 9 pumas, 8 leopards, 7 cheetahs, 7 lynx, 3 caiman, 2 alligators, 13 crocodiles, 2 lions, 145 ostriches, 115 lemurs, 412 bison, 6 wolves, 300 boar, and 300 venomous snakes to be kept as private pets.

Who knows how many of these beautiful, but deadly creatures will find their way out into the wilderness in years to come. Some of which, over time, may become just another regular, beast from abroad; roaming the wilds of our beautiful land.

Written by Andrew McGrath 


  1. You don't mention Reeves' muntjac, which I have seen on the outskirts of Hartlepool nor my favourite naturalised species, the aesulapian snake, foud around London's Regents Canal and Brecon Beacons.

    1. Hey Bloggerwogger, you are very right, but the list is not meant to be exhaustive, more a sampling if you will of some of the 'Naturalized' exotic animals that are calling Britain home these days! I will attempt to write a more encompassing article about the subject in a few months, I have just received good resources on the subject that will take soe digesting.