Sédentarité, déplacements et répartition des individus dans une population de Lacerta viridis (Laurenti, 1768) (Lacertilia, Lacertidae)

A mark-and-recapture study was undertaken in August 1983, May and September 1987, and May 1988 of a small discrete population of Lacerta viridis occupying an area of 260 x 11—25 m, along the length of a canal in western France. A total of 21 recaptures, over periods of time varying from four months to five years, show that the lizards are highly sedentary with a home range of approximately 200—600 m². Distances between capture and recapture varied from 0—36 m and did not change with time. However, four of the 14 individuals recaptured after more than eight months had clearly changed their home range and reestablished themselves at a distance from the original of 42—143 m. Direct observations and short-term recaptures suggest that different parts of the home range are exploited successively at different times. During several days, or even weeks, a marked individual will be found in a small area of 10—15 m long which it will then leave, only to return at a later date. In May, the density of adults and 21-month old sub-adults was approximately 194/ha, with equal densities of males and females. Home ranges, and even temporary activity ranges of individuals, appear to overlap extensively, especially in the most favorable sites. Thus, despite the existence of intense intra-specific aggression between males and noticeable behavioral intolerance between other classes of individuals, high density populations of Lacerta viridis are possible in areas of rather dense vegetation.