Zootoca vivipara

Viviparous Lizard Zootoca vivipara (Jacquin 1787)

Distribution (Figure 7). Included records from Artportalen (N=775): all reports have been included, as there are not any confusion species.

Widespread and common in the Southern, Middle, and Northern Boreal. Widespread but scarce in the Subalpine zone. Locally occurring above treeline in the Low-Alpine zone in favorable microclimates.

As expected, the highest known occurrences in the Scandic Mountain range are gradually lower towards the north: 1000–1050 m altitude in Härjedalen (Sånfjället and Flatruet), 740 m in Pite lappmark (west of Vuoggatjålme), and 690 m in Lule lappmark (Vastenjaure).

There is just one record from a truly far offshore island (Stora Fjäderägg, Västerbotten; Figure 7; Elmberg 1995). Although common in seashore habitats on the mainland along the entire Baltic coast of North Sweden, there are surprisingly few records even from nearshore islands. An exception may be the archipelago in southern Norrbotten, where the species occurs on some outer islands (e.g., Stor-Räbben and Vargön, green offshore area in Figure 7; Stefan Andersson, personal communication). For North Sweden as a whole, this indicates a limited dispersal capacity over brackish water.

There are no indications of changes in distribution over the last 50 years.

Habitat and movements. Found in almost any habitat offering a combination of basking sites and protective low vegetation. Favored natural habitats are forest edges and clearings, stony slopes, rock outcrops, sandy areas, and shores of lakes, rivers and the sea (Figures 12, 14). It often occurs among Juniperus communis, Calluna vulgaris, Empetrum nigrum and other plants typical of dry sun-exposed conditions. Closed forest, tall grass, and wet habitats are avoided. Anthropogenic habitats are widely used, for example clearings under powerlines, clear-cuts, edges of fields and meadows, stone walls, cairns, and roadsides (Figures 13, 19).

There have not been any dedicated studies of this species in North Sweden. As far as known, it spends the entire annual activity period in the habitats mentioned above. Daily and annual movements are not known but appear very limited. Subterranean hibernation sites are found in or close to the summer habitat, usually in south-facing situations.

Abundance estimates and trends. There are not any published abundance data, but estimates based on extensive field work in the Umeå area (Västerbotten) 1975–1994 run in the neighborhood of> 500 adults /km 2 in representative landscapes near the coast (Elmberg, unpublished).

There are no indications of changes in abundance over the last 50 years.