Vergilov V, Tzankov N, Kornilev YV & Popgeorgiev G. 2022. 
North-western Journal Of Zoology 18 (1): 40-46. Link. Published online 15 June 2022.

Abstract

The Snake-eyed Skink Ablepharus kitaibelii (Bibron & Bory de Saint-Vincent, 1833) is one of the smallest lizards in Europe, and this, combined with its secretive lifestyle, makes population studies on the species very difficult. Only a few studies concerning sparse data, mainly on the species’ activity, have been published, but its population ecology has received less attention. We aimed to collect information about population parameters such as population size, survival rate, Body Condition Index (BCI), and individual movements. Here we present data from a four-year Capture–Mark–Recapture study on a population of A. kitaibelii from Northwestern Bulgaria. We marked 415 individuals (136 females, 108 males, and 171 juveniles). Rapid sexual maturation and extended egg-laying period led to an overlapping of the generations in time – in many individuals, the onset of sexual maturity overlaps with the period of the next hatchlings – probably crucial for the survival of the species. The Cormack–Jolly–Seber model estimated that the average adult population size for the study period was N = 220 (95%CI: 102–490). Long-term recaptures suggest that it is generally sedentary, likely without performing many long-distance movements more than 60 m and usually maintaining a small individual range. A low and uneven recapture rate by season was due to the secretive lifestyle of the species and seasonal changes in habitat characteristics such as overgrowing with grasses and/or bushes.