Species distribution modelling leads to the discovery of new populations of one of the least known European snakes, Vipera ursinii graeca, in Albania

Abstract

Vipera ursinii graeca is a restricted-range, endemic snake of the Pindos mountain range in the southwestern Balkans. The subspecies was previously reported from eight localities in Greece and one locality in southern Albania. We used species distribution modelling based on climate data from known localities in Greece to estimate the potential distribution of the subspecies. The model predicted suitable areas for eleven mountains in southern Albania, which we visited in ten field expeditions in four years. Based on 78 live individuals and 33 shed skins, we validated the presence of the snake on eight of the eleven mountains. Six populations (Dhëmbel, Llofiz, Griba, Shendelli, Tomorr and Trebeshinë Mountains) are reported here for the first time. Morphological characters undoubtedly supported that all individuals found at these new localities belong to V. u. graeca. Genetic analysis of mitochondrial DNA sequences also confirmed the identity of the snakes as V. u. graeca and a low number of identified haplotypes suggested low genetic variability among populations despite significant spatial isolation. All localities were subalpine-alpine calcareous meadows above 1600 m. These high montane habitats are separated by deep valleys and are threatened by overgrazing, soil erosion, and a potential increase in the elevation of the tree line due to climate change. Our surveys increased the number of known populations by 60% and the known geographical range of the subspecies by approximately 30%. Our study serves as a baseline for further ecological research and for conservation measures for one of the least known European viperid snakes.

Nuclear markers support the mitochondrial phylogeny of Vipera ursinii–renardi complex (Squamata: Viperidae) and species status for the Greek meadow viper

“…Geographic and taxon sampling. Two samples of V. u. graeca from Albania were included in this study (Mizsei et al 2016), both representing the same mtDNA haplotype as the published sequences from Greece in previous studies (CYT B, ND4;Ferchaud et al 2012). Other specimens investigated were samples representing montane populations of Vipera ursinii macrops (Albania, Montenegro), V. u. ursinii (Italy), V. ursinii ssp.…”

“…Morphological Diagnosis. This taxon differs from all other members of V. ursinii-renardi complex by having the following combination of morphological characters (Nilson & Andrén 1988;Nilson & Andrén 2001;Mizsei et al 2016): small body size (for males a snout to vent length (SVL) max. 40.6 cm, and tail length is 5.4 cm, and for females a SVL max.…”

“…A member of the genus with a surprising phylogenetic placement is the Greek meadow viper, Vipera ursinii graeca Nilson & Andrén, 1988, which is a rare taxon described three decades ago. The species lives in high elevation meadows (1600-2300 m) of the central and southwestern Hellenides mountain range (Dimitropoulos 1985;Nilson & Andrén 1988;Korsós et al 2008;Mizsei et al 2016). According to the phylogenetic study of Ferchaud et al (2012), V. u. graeca is sister to all other clades of ursinii and renardi in the V. ursinii-renardi complex and forms a distinct, divergent clade sister to the others, isolated in fragmented habitats in the Pindos mountains.…”

A trait‐based framework for understanding predator–prey relationships: Trait matching between a specialist snake and its insect prey

“…The Greek Meadow Viper, Vipera graeca (Nilson & Andrén, ), is a poorly known cold‐adapted snake living in alpine meadows between 1,600 and 2,200 m above sea level in the Pindos mountain range in Albania and Greece (Mizsei et al, ). Originally described as a subspecies, molecular studies confirmed the lineage as basal to the entire complex (Ferchaud et al, ; Nilson & Andrén, ) and was subsequently elevated to species level (Mizsei, Jablonski, Roussos, et al, ).…”

“…Although new techniques for diet tracing (stable isotopes, fatty acid analysis and DNS‐based methods) have advanced considerably recently, visual analysis has several advantages such as the simplicity of sample collection, storage and processing, and the possibility of obtaining information on the species identity, life stage, age or sex of prey and the number and relative abundance of prey consumed, thus still widely used in trophic studies and monitoring programs (Nielsen et al, ). In each population, we intensively searched for snakes (total sampling effort c. 5,700 person‐days) during the vipers’ active season ranging from April to September (Mizsei et al, ). The captured individuals were kept in separate textile bags for 2–4 days (min.…”