This taxon has traditionally been considered a subspecies of the widespread European slow-worm Anguis fragilis, which recent genetic research has confirmed is a species complex (Gvoždík et al. 2010). Gvoždík et al. (2010) identified A. colchica as a distinct clade within the complex, and elevated it to species status. These authors also addressed the status of the older name Anguis incerta, and recommend that it be considered a nomen oblitum in order to protect the prevailing name A. colchica to preserve nomenclatural stability.

Anguis colchica orientalis Anderson, 1872 described from the Iranian province of Gilan was revalidated based on molecular genetic analysis by Gvoždík et al. (2010).

European regional assessment: Least Concern (LC)
EU 27 regional assessment: Least Concern (LC)

This Eastern Slow Worm is widespread across parts of central and eastern Europe, and is assessed as Least Concern for Europe and for the EU27 Member States on the basis that this species is widespread, likely to be common, and any declines are likely to be localised.

As presently understood, this species' range in Europe includes Finland, Lithuania, Slovakia, the eastern Czech Republic, northeastern Poland, eastern Hungary (Szabó & Vörös 2014), Romania, Russia (Speybroeck et al. 2016), Latvia (Gvoždík et al. 2021), northeastern and northern Serbia (Urošević et al. 2020), Bulgaria and Ukraine (Kamali 2020). Its range limits relative to the western species Anguis fragilis, with which it was historically confused, were subsequently clarified by Jablonski et al. (2021), who analysed the distribution of the species and compiled the most complete inventory of available distribution records (n=4,166), although ambiguity remains regarding the exact range limits along the long contact zone with Anguis fragilis. Genetic evidence indicating that A. fragilis ranges along the Baltic coast implies that the contact zone extends from the Balkans to northern Poland (Gvoždík et al. 2021). It occurs from sea level to 2,700 m asl. (Jablonski et al. 2021).

Outside the European region, it occurs in northern Türkiye, the Caucasus with records from Caucasian Russia, Armenia, Azerbaijan and Georgia and northern Iran (Bannikov et al. 1977, Jablonski et al. 2021).

The species with which it was formerly confused is reasonably common, although localized declines may be underway in both species as a result of intensive agricultural development. Population trends are however difficult to monitor as the species spends much of its time underground (B. Schmidt pers. comm.).

In the forest zones of both the European and Caucasian parts of Russia, this species is common and numerous, although it is naturally less common in areas of the forest-steppe and steppe zone where limited areas of suitable habitat are available (I. Doronin pers. comm. 2022). In the Moscow region, the densest settlements (20–25 ind./ ha) and occupied areas were found in the northwestern region (Upper Volga Lowland) (Starkov 2000). A population decline has been observed within large urban agglomerations (for example, Moscow and St. Petersburg).

Slow worms occur in a range of habitats, generally in well-vegetated, relatively humid situations (Speybroeck et al. 2016). The species inhabits broad-leaved and mixed forests. In Romania, it has been recorded from beech-spruce and spruce forest (Iftime and Iftime 2013). It can sometimes be found on the outskirts of fields and meadows, and in gardens (I. Doronin pers. comm. 2022). In the central suburbs of Moscow it occurs on karst outcrops, where densities can reach 10 individuals /ha (Starkov 2000). Animals are most often surface active in wet weather, but the majority of their time is spent beneath trunks of fallen trees, in rotten stumps, on the forest floor, or in animal burrows (I. Doronin pers. comm. 2022).

Animals are diurnal and semi-fossorial, typically basking in sheltered situations within vegetation, and sheltering beneath debris (including man-made objects) or in rodent burrows (Speybroeck et al. 2016, Kamali 2020). At least in Russia, animals enter winter dormancy no earlier than the second half of September and emerge between mid-March and late May (I. Doronin pers. comm. 2022). Slow worms are viviparous, with litters of 3-26 young produced following a three month pregnancy (Speybroeck et al. 2016). Sexual maturity is reached in the 3rd year of life and animals are very long-lived, with longevity in captivity of 30-35 years (Bannikov et al. 1977; Ananjeva et al. 1998).

This species is unlikely to persist in cultivated areas that lack dense vegetation, and the species' absence from the cultivated steppe of northernmost Serbia is likely to be genuine rather than a sampling artefact (Urošević et al. 2020). Expansion of run-of-river small hydropower plants in the hilly parts of the Balkan peninsula could indirectly, through overall decrease of humidity, negatively impact local subpopulations (Crnobrnja-Isailović et al. 2021). In areas of forest-steppe and steppe where suitable (forest) habitat is limited the species is vulnerable to deforestation (I. Doronin pers. comm. 2022). It is widely persecuted, as people mistake it for a snake (I. Doronin pers. comm. 2022).

There is no known use of or trade in this species.

Regional assessment in Hungary evaluated the species as Near Threatened (NT) due to size of known populations, and climatic scenarios potentially affecting the species negatively (Halpern et al. 2019).

This species has been recorded from multiple protected areas.