Britain’s lost reptiles and amphibians
The word “rewilding” has many different connotations for different people here in the UK. The public image of such schemes includes reintroductions of key species which once roamed the British Isles, such as bears, wolves or lynx - an image of which many people are not too fond of due to concerns of safety of human life or livestock. While I have many opinions on the subject of rewilding large mammals to the UK, this blogpost will focus on the little guys - reptiles, and amphibians, which once (or may have once) inhabited the country in recent times: animals which most people wouldn’t even think about when rewilding is mentioned, but are arguably equally as important.
Many species of reptiles and amphibians inhabit mainland Europe. Although these animals face their own challenges with regards to habitat loss or human action, they still persist. So the question arises, why is the reptilian / amphibian fauna so low in the UK compared to the mainland? And if these species did once live here, what happened to them?
The fossil record of recent (passed few thousand years) details many different species of reptiles and amphibians having existed in the recent history (Holocene) of the UK, some of which we will touch on below. There are also a number of species found in Northern Europe which may at some point have lived on the British Isles but have no fossil record.
European pond terrapin
The European pond terrapin (or turtle) - scientific name Emys orbicularis
The European pond terrapin is one of the most common terrapins (or pond turtles) living in Europe. Only a few other species of pond turtle are found in Europe, and most of these live in much warmer climates of southern Europe (eg. the genus Mauremys). Unlike these other turtles however, the European pond terrapin Emys orbicularis is much more suited to the colder temperatures of Northern Europe, existing as far North as parts of Denmark (though these are possibly escapees). This species hibernates in very cold waters by lying still for months on end (in fact it is required that these animals are allowed to hibernate in waters around 4 degrees if keeping them as pets).
Emys orbicularis definitely lived in the UK - as recent as 8,000 years ago (to even 4,000 years ago by some sources). How it went extinct is uncertain, though this may have been due to one of the several short lived cooling events in recent history. The climate now, especially with a general warming trend, is likely more than adequate for these turtles to live in the UK once more - and released populations of these turtles (along with non native red-eared sliders from North America) show how this is possible. Although none of these turtles are known to have reproduced here definitively, there are possible hatchlings of other released species, including a definite breeding animal in the similar climate of Denmark.
Should we reintroduce European pond terrapins to the UK?
We have established that these species are definitely capable of living in the climate of the UK. Reproducing is another matter: these terrapins need a consistent high temperature (25-30 degrees C) for around 60 days to successfully hatch offspring. The hatchlings sex is also temperature dependant, with higher or lower temperatures dictating whether males or females will hatch. These challenges are usually counteracted by the long lifespan of these animals in their native countries who reproduce many times throughout their life.
Another argument against reintroduction is the time which they went extinct in the UK and whether it is worth reintroducing a long extinct animal to an ecosystem which may no longer need it. This question clearly hasn’t stopped other reintroductions of species to the island: Bison became extinct maybe 6,000 to at most 11,000 years ago in the British isles, yet they are scheduled to be reintroduced this month (though in a fenced off area for the time being).
So all things considered, should we reintroduce these animals back to the country? I believe further study is needed, but personally these animals could probably do well if reintroduction schemes were put in place to monitor the progress of breeding etc. . Carefully planned schemes can very much work, for example the great bustard project which successfully reintroduced a notoriously difficult bird to breed and naturalise, to Salisbury plain, England. Not only would this increase the native biodiversity of the UK, but alongside other keystone species and increased conservation these animals could once again thrive in this country.
Aesculapian snake
The famous Aesculapian snake, Zamenis longissimus
The Roman god of healing, Aesculapius (or Asclepius for the Greek god) has traditionally been depicted with a snake entwined staff, a symbol still used today in many parts of Europe in places of medicine. This snake is usually regarded as the Aesculapian snake, Zamenis longissimus (previously Elaphe longissimus). It is the longest of its kind in Europe, reaching lengths of up to 2 metres in some cases - though in colder climates it usually caps at around 1.5 metres. The snake is a predator of rodents up to the size of large rats, and occasionally birds in their native range - definitely not a specialised predator.
The fossil record shows that, like the European pond terrapin, this species did indeed exist in the UK in recent times - having gone extinct roughly 10,000 years ago. Unlike its chelonian relative however, the Aesculapian snake is known to have bred multiple times in the UK in recent years: populations exist all around the country, including parts of Wales, and even in central London where they feed on the exceptionally large population of rats.
Should we reintroduce Aesculapian snakes to the UK?
Aesculapian snakes are probably better suited to the environment of the UK. As these animals have already bred and basically have established populations which are being monitored currently, it would be interesting to see how these animals interact with other native animals.
One problem with introducing animals is public perception. Many people (wrongly) are afraid of snakes due to various reasons / upbringings (this is not limited to just snakes - the same could be applied to a number of other reintroduction contenders.) Education of communities in close proximity to these animals is paramount: this way, stigmas against certain animals can be hopefully changed. Unfortunately, we live in a world which is (mostly) against nature, which unfortunately means that ignorance about reintroduction will remain for quite some time. Snakes are not dangerous, bloodthirsty killers.
If anything, reintroducing the Aesculapian snake may do wonders for British nature: by controlling numbers of rats, mice and other pest species, the Aesculapian snake may bring joy in the future, rather than terror. Here’s hoping.
European tree frog
European tree frog - scientific name: Hyla arborea
It is uncertain whether the European tree frog existed in the UK in recent history. Fossils of this genus have been found throughout the mid - late Pleistocene however in the midlands of England and Northumbria, so they at least existed in England within the last 100,000 years. This species of frog has a current range extending up to the north of France and parts of Denmark, similar in climate to southern Britain - some are found as far north as Sweden. Despite being called tree frogs, northern European tree frogs aren’t primarily arboreal, preferring marshland and open scrub. These frogs are also especially hardy animals, being able to survive being frozen alive - thus the “cold climate” of the UK is more than suitable for these wonderful amphibians.
Although released populations do exist in the UK, a possible native colony existed until recently in the New Forest. Unfortunately, this population is now likely extinct. Unfortunately for the European tree frog (and other animals in this blog) the native status of these animals is rarely taken seriously meaning they aren’t protected under law. It is also illegal to capture, and then release a “non native” animal here in the UK, so many amateur naturalists kept these animals when they were captured.
Should we reintroduce these animals to the UK?
Although the fossil record on these frogs is a little hazy for the recent past, a very convincing case can be made that the New Forest population was indeed a native one. Added on to the fact that the European tree frog is incredibly adaptive to cold conditions, I think an equally strong case can be made for a reintroduction of this species.
Many other species that once existed in the UK have not been covered in this article. I may expand upon this with a part 2 at one point, maybe touch on some other really interesting herps (such as the possibility of the fire salamander and the western green lizard being extinct natives).
I believe that all the animals in this list should have a chance of being reintroduced to the UK. Although small, these animals were once key species in their habitat, not only the fact that they add to the low biodiversity of this country. My hope is that in the coming years the wave of rewilding we are seeing here in the UK continues to grow, and that those who live in our country will have the opportunity to fully appreciate the natural spaces and wildlife of Britain.
