Speybroeck et al. (2020) summarised the results of phylogenetic and taxonomic work investigating the Vipera ursinii over the preceding decade. They concluded that Vipera renardi and V. graeca warrant continued recognition as valid species following Ferchaud et al. (2012) and Mizsei et al. (2017) respectively. Conversely, they concluded that Vipera lotievi and - through inference based on its similarity to V. lotievi, as genetic data were unavailable - V. shemakhensis should be regarded as junior synonyms of V. ursinii. Subsequently Freitas et al. (2020) found that V. shemakhensis exhibited little genetic divergence from V. eriwanensis.

The species has four presently recognised subspecies one of which - V. u. moldavica - includes Danube Delta populations assigned by some authors to a dubious subspecies of Vipera renardi (Speybroeck et al. 2016).

Global and European regional assessment: Vulnerable (VU)
EU 27 regional assessment: Vulnerable (VU)

This European endemic species is listed as Vulnerable (VU B2ab(ii,iii,iv,v)) because its area of occupancy is estimated at 520 km² in Europe and 508 km² in the European Union, its population is severely fragmented, and there is continuing decline in the extent and quality of its habitat driven by multiple pressures, and an inferred decline in the number of mature individuals based on the species' apparently substantially lower densities than historical reports suggest and the ongoing impacts of predation. Multiple subpopulations - including those at range margins in Austria and apparently Moldova and Ukraine - have been lost over the past several decades and others remain at risk, and consequently, a continuing decline is inferred in both the area of occupancy and the number of subpopulations. The northern and eastern lowland subspecies (Vipera ursinii moldavica and V. u. rakosiensis) are especially threatened and are considered to be nearly extinct.

This European endemic species has a very fragmentary range that is restricted to postglacial relictual habitats in southeastern France, the central Apennines of Italy, western and central Hungary, southern Croatia along the Adriatic coast, central and southern Bosnia-Herzegovina, Montenegro, southwestern-most Serbia (including Kosovo), northern Albania, northwestern North Macedonia, Moldova, and central and eastern Romania. There is a single record from extreme southeastern Ukraine (Geniez 2018), where the species is probably extinct (Mizsei et al. 2018), however this may not be a reliable record, and is not supported by a specimen (B. Halpern pers. comm. 2022). It is considered extinct in Austria and the existence of an extant subpopulation in Bulgaria, where it historically occurred in the northeast and is generally presumed to be extinct (Geniez 2018), is "debatable" (Speybroeck et al. 2016, Móré et al. 2022). It is probably extinct in part of western Romania (although at least five extant subpopulations are known in Transylvania - B. Halpern pers. comm. 2022). It is close to extinction in Hungary and may be extinct in Moldova (although its persistence in relict habitat in the Dniester-Prut area is possible, and available data are insufficient to confirm its extinction in Moldova; Ţurcan 2021). The species exhibits distinct lowland and montane morphs, the former of which is usually found below 400 m and the latter from 1,000 up to about 2,500 m asl (Nilson and Andrén 2001).

The species is generally uncommon or rare, and patchily distributed. Many subpopulations have experienced "severe declines" over the past several decades (Console et al. 2020). While historical data on abundance are lacking there are several historical reports of high densities in the Hungarian subspecies Vipera ursinii rakosiensis, it is the most common subspecies in natural history collections, and reptile collectors report being able to collect 30-40 in an "average day" as recently as the 1970s (Móré et al. 2022). Today, this subspecies is nearly extinct, occurring at low densities in the few surviving subpopulations in Hungary and Romania, and on average less than one individual is recorded during a full-day search (Móré et al. 2022). The degree of fragmentation across the species' distribution area as a whole has increased significantly since the last Red List assessment of this species, and in central Italy is now "very fragmented" (C. Corti and E. Razzetti pers. comm. 2022)

The species is considered to occur as a severely fragmented population as the known subpopulations are small and mostly very highly disjunct, being separated by both natural and anthropogenic barriers to dispersal. Nearly all are subject to anthropogenic pressures such that they are at risk of becoming unviable and that unassisted rescue effects are unlikely. There remain some montane subpopulations that are not subject to direct human impacts (though are likely vulnerable to climate change), and the discovery of several lowland subpopulations in areas of Transylvania not managed for conservation suggests that limited population recovery or recolonisation may be possible without human assistance (B. Halpern pers. comm. 2022).

The Meadow Viper is primarily associated with open meadows and hillsides. Upland subpopulations are generally found on well-drained rocky hillsides, steppe and meadows, typically on karst, while the lowland forms are found in steppe on sandy soils, either dry or damp meadows and dune areas (Speybroeck et al. 2016). A study investigating the effectiveness of habitat restoration in Hungary indicates that the snake requires structural diversity in vegetation (Mizsei et al. 2018). The lowland forms are sometimes found in marshy areas. The montane subpopulations are found in open grassy habitats with or without bushy vegetation.

Female Meadow Vipers give birth to between four to eight live young (more rarely up to 15 according to Geniez 2018, 18 according to Speybroeck et al. 2016). Upland subpopulations (Vipera u. ursinii, V. u. macrops) exhibit biannual (occasionally triannual) reproduction and mean litter sizes of six to eight. Reproduction is annual in lowland subspecies (V. u. rakosiensis, V. a. moldavica) and litters are larger (mean 10-15 young, and an observed maximum of 27 in Hungary, in lowland areas; data summarised by B. Halpern pers. comm. 2022). Across 5 years of monitoring in a Montenegrin montane subpopulation, reproduction was biannual and annual mean litter size ranged from 4.3-6.2 (J. Crnobrnja-Isailović pers. comm. 2022). In captivity, animals mature at three (male) to four (female) years and live for at least 15 years (B. Halpern pers. comm. 2022).

The Meadow Viper is considered one of the most threatened reptiles in Europe (Console et al. 2020). Although the high level of fragmentation in this species' population is largely natural in origin, anthropogenic clearance and degradation of steppe habitats is widespread throughout the species' range and the major driver of declines (Edgar and Bird 2006). Most formerly known meadow viper habitat has been completely destroyed (Móré et al. 2022). Most remaining localities (61%) have been identified as habitats with a high risk of negative change, principally mesic grassland and traditional arable land (Janssen et al. 2016, Console et al. 2020). In central Italy, there is one studied example of negative impacts resulting from excessive growth of dwarf mountain pine cultivation (E. Razzetti pers. comm. 2022). The subspecies Vipera ursinii rakosiensis - which historically ranged from the Vienna Basin across the Great Hungarian Plain to Transylvania, and was considered "common and abundant" in this area as little as a century ago (Móré et al. 2022) - was lost from most of its Romanian range in the 1950s and from Austria by the 1980s (Gvoždík et al. 2012). In the Hungarian localities, where little suitable habitat remains, evidence of inbreeding has been reported (Újvári et al. 2000), but work in preparation may contradict this (B. Halpern pers. comm. 2022). The subspecies V. u. moldavica was considered widespread in Moldova until the 1960s, but no extant subpopulation has been recorded in this country since the 1970s despite field surveys throughout most of the 21st Century which included apparently suitable steppe habitat (Ţurcan 2021). This decline coincides with the loss of about 90% of Moldova's natural steppe habitat, largely due to agricultural conversion and the degradation of remnant habitat by overgrazing (Ţurcan 2021).

The conversion of traditionally farmed meadows to intensively cultivated and grazed land has caused significant declines in lowland grasslands (Péchy et al. 2015, Mizsei et al. 2018). In addition to the direct changes to vegetation structure caused by agricultural intensification - which include the loss of buffer zones between fields that provide critical habitat for the viper - pesticide use may result in both changes in habitat structure and the loss of prey resources (Zamfirescu et al. 2011). The species was assigned the highest pesticide risk factor among European reptiles in the index compiled by Wagner et al. (2015) because 45% of identified Special Areas of Conservation in which it occurs are subject to agricultural use. Afforestation of alpine grasslands (resulting from the abandonment of traditional agricultural practices) degrades montane meadow habitats by reducing the availability of basking sites (Filippi and Luiselli 2004).

Road construction through grassland habitats further fragments subpopulations, potentially reducing genetic variation to a degree that may lead to local extinctions (Újvári et al. 2002, Filippi and Luiselli 2004).

Additional threats (summarised by Console et al. 2020) have been identified from degradation due to increased populations of wild boar (which both prey on the species and damage its habitat), the development of infrastructure to support winter sports in montane localities, urbanisation, direct persecution, and upslope shifts in the treeline resulting from climate change. Grazing pressure - especially from sheep - has been implicated in local viper extinctions through the destruction of tussock habitats and mammal burrows used as shelter and basking sites (Zamfirescu et al. 2011). Pigs and geese directly prey on vipers (Zamfirescu et al. 2011). Fire may render habitats unsuitable for the snake, and is the possible cause of a local extinction reported in a montane area of France (Lyet et al. 2009). Additional predation pressure is likely to be exerted by native mammalian predators, which are increasing in density across the entire north temperate zone, and these authors found that it was a regular prey item for European badgers and red foxes at one study site in Hungary (Móré et al. 2022). These authors estimated that the number of vipers preyed on by these two species alone over a nine month period may be as high as ~33% of the local subpopulation.

Illegal collection has the potential to impact subpopulations due to the small size of many (Kovács et al. 2002). Collection for the pet trade is believed to have contributed to the extinction of subpopulations of V. u. rakosiensis in Hungary and Austria, and to have "seriously disturbed" meadow viper subpopulations in France and Italy (summarised by Zamfirescu et al. 2011).

There is illegal collection of this species for the pet trade in parts of its range. Although this is infrequently reported, a number of subpopulations are well-known and accessible (Zamfirescu et al. 2011).

This species is listed on Annex II of the Bern Convention, and on Annex II and IV of the European Union Habitat and Species Directive. Vipera ursinii is listed on Appendix I of CITES. It has been the subject of four LIFE projects targeted at both understanding its conservation needs and actively conserving remnant subpopulations (LIFE04 NAT/HU/000116 "Establishing the background of saving the Hungarian meadow viper (Vipera ursinii rakosiensis) from extinction", LIFE05 NAT/RO/000158 "Saving Vipera ursinii rakosiensis in Transylvania", LIFE07 NAT/H/000322 "Conservation of Hungarian meadow viper (Vipera ursinii rakosiensis) in the Carpathian-basin" and LIFE18 NAT/HU/000799 Viability improvement of Hungarian meadow viper populations and habitats in the Pannonian region").

It is considered Critically Endangered in the Red Data Book of Romania (Botnariuc and Tatole 2005), Endangered in France (UICN France, MNHN and SHF 2015), Italy (Rondinini et al. 2022), Endangered in the Western Balkans (in Croatia [Jelić et al. 2012], Bosnian Federation [Lelo et al. 2016], Serbia [Tomović et al. 2015] and North Macedonia [Sterijovski and Arsovski 2020]). A European Species Action Plan (Bern Convention) was developed for this snake (Edgar and Bird 2006), but implementation is uncertain, and a revision of this plan is in development (B. Halpern pers. comm. 2022). The majority of its known subpopulations fall within protected areas, but all except strict nature reserves are subject to some degree of human presence (Console et al. 2020). The extant subpopulations of V. u. rakosiensis are poorly-covered by protected areas, and the subspecies is absent from any protected areas in Romania (Console et al. 2020). In-country conservation measures, such as maintaining suitable areas of meadow habitat, are underway to conserve some subpopulations (e.g. Hungary and Romania) (CoE 2003), and the species is subject to conservation attention in the management plans of many national and European protected areas (Console et al. 2020). The species is likely to be reassessed as Endangered in Italy (C. Cort and E. Razzetti pers. comm. 2022) on the basis of fragmentation. The species is also assessed as Endangered in the 2015 French Red List.

Detailed recommendations for conservation action to protect this species can be found in Edgar and Bird (2006), but these are in need of review. Habitat reconstruction, grassland management that accounts for the needs of the species, ex situ breeding and experimental reintroductions to restored habitat have been undertaken since 2004 in efforts to rescue the Hungarian subspecies (Péchy et al. 2015), but densities of the snake remain too low for the success of these initiatives to be evaluated and may be hindered by the impacts of predators (Móré et al. 2022). Anti-predator fencing is recommended at sites targeted for the reintroduction and restoration of viper subpopulations (Móré et al. 2022). Despite general surveys in Moldova, targeted searches have not been extensive enough to reliably identify any extant subpopulation here and urgent research is recommended to identify any surviving Moldovan subpopulation in order to ensure its conservation (Ţurcan 2021). Active predator control is important to ensure the survival of subpopulations (B. Halpern pers. comm. 2022).