Vipera walser

biology_ecology

Near-future threats and conservation Vipera walser appears to occur only in a very limited area in the Alps north of Biella (Fig. 8). It is very likely that all native populations of adder south of the Alps and west of the river Ticino belong to the species herein described. Based on the Italian Atlas of Amphibians and Reptiles (Sindaco et al. 2006), the current distribution area (‘ extent of occurrence’) is almost certainly <1000 km 2. Consequently,. walser should be classified as ‘ endangered’ according to (2014) Red List criteria B 1 a / B 2 a. If we consider that the population is strongly fragmented, or that the actual area of occupancy is probably <500 km 2 and fragmented (Red List Categories and Criteria: Version 3.1. Second edition), then. walser appears to be among the most threatened vipers in the world. The new taxon’s sister species. darevskii, with area of occupancy <10 km 2, is now listed as ‘ critically endangered’ (Tuniyev et al. 2009), whereas. kaznakovi (related to. darevskii and thus to. walser) is considered ‘ endangered’, meaning that the entire clade is highly threatened with extinction. Within its restricted range,. walser appears to be quite common in suitab

A new vertebrate for Europe: the discovery of a range-restricted relict viper in the western Italian Alps

description

Paratype variations Details and meristics for the analysed individuals, including the type series, are summarized in Table 3. Description of the holotype Adult female conserved in 70 % EtOH in rather good condition, with the body slightly swollen probably due to preservation. Snout-vent length (SVL) 515.2 mm, tail 55.0 mm, ratio of tail proportion (/ SVL) 0.107. Two apical scales in contact with the rostral. Head oval shaped, wider in the temporal region, neck not very distinct, snout rounded. Frontal single, and larger than any other scale on head, five parietals. Rostral slightly higher than broader; nasal roundish, nostril circular and approximately in the centre of the nasal; one internasal on left side of the head and two on right side; perioculars 11 – 10; two rows of suboculars on both sides of the head; circumoculars separated from nasals by six and five loreal scales, respectively, on right and left side; supralabials 9 – 9, the fourth and the fifth below the eye; 147 ventrals; 31 divided subcaudals (excluding spine); anal entire; 21 scale rows at midbody. Dorsum is brown in colour with a continuous and regular darker brown zigzag. Head is reddish-brown with scattered, fai

A new vertebrate for Europe: the discovery of a range-restricted relict viper in the western Italian Alps

diagnosis

Differential diagnosis Vipera walser sp. nov. is generally similar to the species of the subgenus Pelias and can be confused with V. berus, which co-occurs on the Alps in allopatry (Fig. 6, Table 2). The species differs in a generalized higher count of cephalic scales, in particular the ones listed below (V. berus in parentheses): higher number of crown scales: 7 – 30, mean 17.4 (versus 4 – 22, mean 13.0); loreals: 4 – 15, mean 9.36 (versus 2 – 12, mean 6.72); and, to a lesser extent, perioculars: 16 – 23, mean 19.8 (versus 13 – 23, mean 18.4) (see Table 2). V. walser, in contrast to V. berus, also shows a marked tendency towards fragmentation of the cephalic large shields: the parietal scales are often completely broken down into several smaller scales: 2 – 14, mean 6.3 (versus 2 – 10, mean 2.4; see also Fig. 7). Less commonly, also the frontal scale is fragmented into smaller scales. Some individuals exhibit a dorsum of the head covered in small, irregular scales, like in V. aspis. V. walser has between 1.5 and 2 rows of subocular scales on both sides of the head in 85 % of the analysed specimens (V. berus has typically one row of suboculars, with the exception of some population

A new vertebrate for Europe: the discovery of a range-restricted relict viper in the western Italian Alps

discussion

Conclusion The present study described and named a new viper species,. walser, which shows strong genetic divergence and clear morphological differentiation from all other known European viper species. The new taxon occurs in a restricted area of the southwestern Italian Alps and shows close affinities with the Caucasian species. dinniki,. darevskii and. kaznakovi, opening unexpected and interesting biogeographic scenarios. The very small extent of occurrence of the new species implies a particularly high threat level, and thus conservation managements should be developed. The protection of its habitat, the limitation of the forest regrowth, but also the evaluation of its likely future distribution given climatic changes (for the long term) or struggle against culling (short term) are key elements to investigate. Involvement of local authorities, foundations and other stakeholders will be crucial in realizing effective protection of this species.

A new vertebrate for Europe: the discovery of a range-restricted relict viper in the western Italian Alps