Archives for May 2026

Roger Downie, Froglife and University of Glasgow

The Alpine Newt was first scientifically described by Laurenti in 1768 from the Austrian Alps and named Triton alpestris. However, although it can occur up to 2370m in altitude, it is not a high-altitude specialist (unlike the Alpine Salamander, Salamandra atra found at heights above 700m), and occurs across much of continental Europe at low and higher levels. It has a continuous distribution but also some isolated populations, such as that in northern Spain, and four sub-species have been described, with some researchers suggesting that these should be designated as separate species, though Frost (2026) argues that more evidence is needed before such a change could be justified.

What about its scientific name? For some time, the Alpine Newt has been in a single-species genus as Ichthyosaura alpestris. However, Mutz and Bohme (2025) contended that this had long been an error, based on a misidentification of Laurenti’s larval drawing, and that the generic name Mesotriton is the correct one. This contention has been rapidly rebutted by Gollmann and Gollmann (2026). For connoisseurs of arcane academic arguments, these two papers are a delight, and I wish the International Commission on Zoological Nomenclature the best of luck in sorting it out. At present, Wikipedia uses Mesotriton  and Frost retains Ichthyosaura.

The distribution map for the Alpine Newt shows it lined up across the English Channel from the UK, suggesting that it is one of the many species with limited dispersal abilities that failed to recolonise the British Isles after the last Ice Age (or was it ever here in the first place?). Its absence as a member of our native fauna is certainly not because conditions here are unfavourable. The most recent survey of its occurrence in the UK by Allain and Lynn (2021) shows that it is the most widely distributed of the non-native amphibians inhabiting the UK. They combined existing records with information from social media posts to identify eleven new populations, many throughout England and a few in both Wales and Scotland. Use of social media in this way had to be done with caution and care: for many members of the general public, the differences between Great Crested and Alpine Newts are not obvious (Alpine adults are a bit bigger than Smooth or Palmates and darker in colour, like Great Cresteds, so confusion is understandable for people not familiar with the different species).

Since, Allain and Lynn, Cathrine (2024) has provided a focussed account of the Alpine Newt in Scotland. He reports four distinct populations: Edinburgh, Dollar, Glenboig and Helensburgh, each at considerable distance from the others. Even in Edinburgh, Cathrine reports three separate populations at Duddingston, Mortonhall Golf Course and Ratho. Ball et al (2024) have shown that the Ratho population is genetically distinct from the other two Edinburgh populations and Cathrine claims that the Ratho newts were deliberately released in an attempt to halt a local development (the objectors thinking that they were releasing protected Great Crested Newts!). Deliberate release of non-native species into the wild is illegal: it is thought that most Alpine Newt populations in the UK are the result of accidental escapes from private collections, although the Edinburgh population apparently came from a University whose colony had grown too large (released before this was illegal). Cathrine claims that the Scottish populations are spreading, especially the one close to the Union canal that is acting as a dispersal corridor.

Three substantial scientific papers have recently investigated the introduced populations of Alpine Newt, aiming to assess their threats to native species. Robbemont et al (2023) sampled 456 individuals across 234 localities throughout Europe, including the British Isles (12 from England; 5 from Scotland; 16 from Wales; 7 from Northern Ireland and 12 from Ireland). One aim of the study was to investigate the effectiveness of trained citizen scientists using the methods of skin and buccal swabbing to recover usable mitochondrial DNA samples. Nearly all recovered samples contained mtDNA and skin swabbing was as effective as buccal, an important result since buccal swabbing needs careful training and is stressful for the newts, whereas skin swabbing is much easier.  The mtDNA confirmed the seven clades identified by previous work (Eastern/Western Europe plus Spain; Italy; Northern Balkans plus Romania; Central Balkans; Montenegro; Vlasina; Southern Balkans. The results were used to ascertain the sources of introduced populations in the Netherlands and the British Isles.

Ball et al (2023) used a variety of approaches to determine the origins of the UK’s Alpine newt populations. Their report is highly technical, but the Discussion section provides a very accessible  account of their findings. The UK population is mostly urban, related to its origins as escapes or deliberate releases from captive collections. Dispersal has been generally low, possibly related to origins in urban habitats with few possible routes for dispersal (an exception being the Edinburgh population noted earlier). They noted that Harper et al’s (2018) eDNA survey of 532 suspected Great Crested newt ponds in three English counties (Cheshire, Kent and Lincolnshire)  had not detected any ponds containing Alpine Newts, despite some of these counties containing  recorded populations. Suggested dangers  from Alpine Newts discussed are: a) hybridisation with native newts: but this is unlikely given that in continental Europe Alpine Newts co-occur with all three native UK newt species with no evidence of hybridisation; b) spread of diseases such as Ranavirus and chytrid: Alpine Newts can carry these diseases, but this threat is most likely only important from specimens imported from the continent, rather than those bred in the UK; c) predation by Alpine Newts on native amphibians, especially eggs and juveniles.

Most recently, North et al (2025) carried out a modelling study on the Alpine Newt’s potential to be an invasive species in Britain. They noted that the first records are from the 1920s, and that there are now over 100 geographically independent sightings. Their assessment is that UK habitats are highly favourable for Alpine Newts, especially the central European clade, and especially central and eastern England, and central and northern Scotland.

Conclusion

It is clear that the Alpine Newt is well suited to inhabiting the UK and already occurs in a large number of small isolated populations across the British Isles. Because most of these are in urban  settings with limited potential for dispersal, rather few of them appear to be  spreading in their range. Many of them derive from the release or escape of captive-bred individuals, so are unlikely to be carrying diseases. However, it remains an offence to release further individuals into the wild. There is currently no plan  to carry out a (no doubt costly) attempt to eradicate these non-native amphibians. If eradication is considered, the example of New Zealand is worth checking out. Alpine newts were first recorded there in 2013, but had likely been released (illegally) a decade before. An eradication programme is in progress, having with some difficulty detected and removed over 2000 newts in the first year (Bell, 2016). The best contribution that interested naturalists can make is to help extend our knowledge of Alpine Newt distribution in the UK, since it is very likely that unrecorded populations remain to be discovered. Please send any records to Froglife who will forward them to the NBN database.

Click here for references