Oct 1

Defending the United Kingdom against invasive, non-native species costs as much as £1.7 billion each year, according to a report by the BBC Countryfile programme.

Photo of a captive American mink on riverbank

The American mink has contributed to a rapid decline in the native water vole in the UK

Threat to native wildlife

The programme highlights the threats that so-called ‘alien’ species are posing to the UK’s native animals and plants, and the high cost of tackling the problem.

Invasive, non-native species are those which have been introduced by humans to areas outside of their natural range and, in the absence of natural predators and parasites, increase and spread to the detriment of native species and human interests. Worldwide, invasive species are considered to be the largest cause of biodiversity loss after humans.

Photo of common carp being fed on by an invasive species, the American signal crayfish

The signal crayfish is a voracious predator and has a negative impact on native crayfish species in Europe

Alien invaders

An example of a problematic invasive species in the UK is the zebra mussel, which arrived in the UK around ten years ago on the hulls of ships from Europe. This species reproduces so rapidly that it smothers native mussels and can block water systems. At Rutland Water in Leicestershire, England, the local water company has to spend around half a million pounds a year dealing with the species, and has installed filters to the reservoir to prevent the zebra mussels from spreading through and choking their water pipes.

Other well-known invasive species in the UK include the American mink, implicated in the decline of the water vole, and the grey squirrel, which is held largely responsible for the decline in native red squirrels.

Photo of grey squirrel collecting leaves in mouth

Introduced to the UK from North America, the grey squirrel has caused a decline in native red squirrels

Foreign plants are also causing major problems. Japanese knotweed alone is estimated to cost the UK economy £165 million each year to eradicate, and mortgages are being turned down due to the damage this species can do to properties. Of the £1.7 billion spent each year on dealing with invasive species in the UK, around £3 million goes towards clearing non-native weeds which can block canals, rivers and ponds.

Threats to health

As well as threatening native species and having an economic impact, invasive animals and plants can also pose risks to human health. For example, the sap of giant hogweed can cause painful blisters, while the hairy caterpillars of oak processionary moths can trigger allergic reactions.

Photo of bluebells in oak wood

Native UK bluebells are threatened by hybridisation with introduced Spanish bluebells

According to BBC Countryfile’s investigations reporter, Tom Heap, “From the grey squirrel, American crayfish, mink driving water voles from our river banks and the small but scarily named ‘killer shrimp’, a whole host of animals and plants are playing their part in colonising our countryside. Luckily, of the 2,000 non-native species living among us, only a few hundred are actually harmful.”

 

Read more about this story at The Telegraph – Defending UK from foreign species costs £26 per person.

Find out more about invasive species in the UK at the GB Non-Native Species Secretariat (NNSS).

View photos and videos of species from the United Kingdom on ARKive.

Liz Shaw, ARKive Text Author

Sep 20

The number of red squirrels in northern England has risen for the first time in 140 years, according to a new survey.

Photo of a red squirrel

The red squirrel is a much-loved species in the UK

Foreign invaders

The native red squirrel was almost wiped out across the United Kingdom after the grey squirrel was introduced from North America in the 1900s. As well as being larger and more adaptable, the grey squirrel carries a pox virus to which the red squirrel is susceptible.

As a result of the grey squirrel’s success, the native red squirrel is now restricted to just a few parts of northern England, the Isle of Wight and Scotland.

Photo of grey squirrel collecting leaves in mouth

The grey squirrel is native to North America, but was introduced to the UK in the 1900s

Red squirrel rise

Now, after years of decline, the red squirrel may be starting to make a comeback. A recent three-month study in 300 woodlands across northern England found that the number of red squirrels has risen by 7% compared to the same period last year. It also found that grey squirrels in the area were declining.

According to the wildlife group Red Squirrels Northern England (RSNE), which carried out the survey, the increase in reds is likely to be a result of conservation efforts to improve their woodland habitats.

Conservationists have also been trapping squirrels, releasing the native reds but killing the non-native greys.

Photo of red squirrel

Although widespread across most of Europe and into northern Asia and Siberia, the red squirrel has undergone a serious decline in the UK

Good for tourism

As well as increasing in number, the red squirrels have also been returning to areas from which they had disappeared. For example, the survey found the species in Ambleside and Rydal in Cumbria for the first time in ten years.

The monitoring has helped us learn that there are now 20 squirrels close to our home here which inspires us to continue our efforts to save this native species,” said Phil Bailey of the Brampton Red Squirrel Group in Cumbria.

Photo of red squirrel feeding

Red squirrel feeding

The involvement of local people has been seen as crucial in helping the red squirrels to return, and this popular species is also an important draw for tourists. According to Simon O’Hare of the RSNE, “The effect on tourism is immeasurable. People never forget seeing red squirrels.”

 

Read more on this story at The Telegraph – After 140 years, red squirrels are fighting back and BBC News – Red squirrels rise by 7% in North after decline.

View more images and videos of the red squirrel on ARKive.

Liz Shaw, ARKive Text Author

Apr 1

Photographic evidence has ended speculation regarding the validity of reported recent sightings of a squirrel-like rabbit in the Forest of Dean, England.

Photograph of a squabbit in the Forest of Dean

Currently the only known photograph of the potentially new mammal species nicknamed the ‘squabbit’ © E. Walsh

Scientists have confirmed the existence of an unidentified but potentially new mammal species in the Forest of Dean, England. Reported sightings of a strange-looking grey squirrel over the past three months have raised nothing more than eyebrows. However, recent photographic evidence and further sightings have put an end to speculation, confirming the existence of a small rodent-like mammal that indeed somewhat resembles both the grey squirrel and the European rabbit.

Affectionately dubbed the ‘squabbit’, this new zoological discovery is stumping scientists as to which species it is more closely related; the grey squirrel is a rodent, whereas the European rabbit is a lagomorph. Its bizarre appearance has led the scientists to believe that it may well be a type of arboreal rabbit. The discovery of a new mammal species in the UK is extremely rare, and the case is being treated with extreme caution. However, should the squabbit be formally described as a new species, this would be one of the most significant scientific discoveries for Britain this century.

Squabbit scat sample

Scat sample of the potential new species collected for DNA analysis © E. Cureuil

Slightly larger than the grey squirrel, the squabbit has predominantly grey fur which is a lighter reddish-brown between the ears and at the back of the neck. It has the long, bushy tail characteristic of the grey squirrel, thought to aide its balance when climbing trees, but larger, rounded paws more similar to those of a rabbit. Indeed, the paws of this species are presenting somewhat of a mystery, as the shape would lead scientists to assume that it is a ground-dwelling rather than tree-dwelling species. Surprisingly, however, the majority of reports of the squabbit have described its nimble climbing behaviour and ease of movement among the treetops. The most unusual feature setting this species apart from grey squirrels is its long, rabbit-like ears that are held upright above its head.

Edouard Cureuil, Professor of Rodent Evolution and Ecology at the Université Thierry Lodé, Paris, commented, “Although there is a possibility of genetic mutation within the grey squirrel population, the morphological differences appear too great to attribute to mutation…initial thoughts are that it represents an entirely new species that has somehow, until now, evaded the human eye.”

Grey squirrel with hazelnut in mouth

The squabbit is believed to have a similar diet to the grey squirrel, feeding on acorns, nuts and seeds, among other things.

The fact that the squabbit has so far avoided detection leads scientists to speculate that the species is predominantly nocturnal, and that Britain’s currently unpredictable climate may have disrupted its behaviour. It is thought to have a diet similar to that of the grey squirrel, feeding primarily on acorns, nuts and seeds, although it has also been observed grazing on grass at the foot of trees. Further studies should confirm whether this species builds burrows underground or nests in trees.

Several theories on the arboreal tendencies of the squabbit have been discussed, the most popular being an adaptation response to predation risks from wild boar and the many birds of prey present in the Forest of Dean. Camera traps have been deployed throughout the small area in which the squabbit occurs, and it is hoped that they will enable scientists to gain further insight into the behaviour of this bizarre new species. Scat samples have also been collected for DNA analysis which should shed some light on the unclear ancestry of the squabbit.

If confirmed as a new species, the squabbit will be a major new addition to Britain’s otherwise well-known fauna, and an exciting step for the world of species discovery.

Explore more newly discovered species on ARKive’s newly discovered species topic page.

Kaz Armour, ARKive Text Author

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