Genetic Scorecard Indicator - Smooth Newt

The smooth newt is widely distributed throughout lowland Britain and Northern Ireland, and its population is estimated to be large with high standing diversity. While all lowland UK amphibians suffered declines in the 20^th century, potentially leading to some loss of diversity (Turner et al., 2022), the large population sizes at breeding sites and the relatively continuous distribution mean that sizeable diversity loss seems unlikely. 

Population definitions:

Populations are defined based on biogeographic evidence. To allow for local adaptation, populations have been assessed based on the five zones that form the basis of UK provenance zones. The disjunct population in the Scottish Highlands has been considered as a separate population. Whilst there is no direct evidence to support this, the similarity of its range and habitat preferences with the great crested newt (Triturus cristatus), which does have a distinct Highland lineage (O’Brien et al., 2015) makes it prudent to consider this a separate population until evidence is found to the contrary.

Ne500: The proportion of populations that have an effective population size of more than 500. 

• Proportion of populations with Ne > 500 in Scotland = 2/3
• Proportion of populations with Ne > 500 in UK = 5/6

PM: Proportion of populations that existed in 2000 that still exist in 2025.

• Proportion of populations maintained in Scotland = 3/3
• Proportion of populations maintained in UK = 6/6

Functional variation

Currently, there is no evidence of threats to the functional diversity of the smooth newt populations within the UK. 

Divergent lineages

There is no evidence of divergent linages in the UK. However, given its separation from the mainland European population and its range edge nature, some adaptive variation may be present. 

Hybridisation/Introgression

While there are rare cases of hybridizations of smooth newts and palmate newt species within the UK and elsewhere in Europe (Beebee & Griffiths, 2000; Babik et al., 2005), there is no consistent evidence of introgression within the smooth newt (Miralles et al., 2023). 

Low turnover - constraints on adaptive opportunities

Smooth newts can produce 200-300 eggs in a season and are quick to colonise newly created ponds (Beebee &Griffiths, 2000) leading to little risk of low turnover. 

Summary of genetic conservation status, encompassing risk and efficacy of current mitigating actions e.g.  

Scotland

• Risk: Negligible
• Mitigation: Not required

Great Britain/UK

• Risk: Negligible
• Mitigation: Not required

Overall Genetic Health status explanation

Overall, the smooth newt has a negligible risk of loss of genetic diversity within all portions of its range in the UK. 

In situ genetic threat level

• In situ Risk for Scotland: Negligible
• In situ Risk for UK: Negligible

With the current, limited, knowledge there appears to be a low risk of loss of genetic diversity within the listed areas.

Confidence in in situ threat level

• Confidence score for Scotland: Medium
• Confidence score for UK: Medium

 This confidence level is based on the lack of current genetic data on the species as well as its overall Least Concern and stable Red List assessment.

Whilst there are no current collections in the UK outside of private collections, the species is commonly kept by hobbyists. 

The smooth newt has limited protection under the Wildlife and Countryside Act, 1981 which prohibits its sale within the UK. However, within Northern Ireland, it is illegal to disturb, kill, injure, capture, or damage/destroy habitat for the smooth newt under The Wildlife (Northern Ireland) Order 1985. The species benefits from pond creation schemes and related habitat management. 

Population

Demographic

N pops assessed/monitored in Scotland = 3/3
N pops assessed/monitored in UK = 6/6

National Amphibian and Reptile Monitoring Programme (UK)  

Genetic

N pops assessed/monitored in Scotland = 0/3
N pops assessed/monitored in UK = 0/6