Site Tenacity in the Terrestrial Salamandrid Salamandra salamandra

-A six-year capture-recapture study allowed us to assess site-tenacity and spatial distribution of site-tenacious individuals in a population of the terrestrial, ovoviviparous Salamandra salamandra from Sintra-Cascais Natural Park, Portugal. The study area, an abandoned orchard, maintained large numbers of S, salamandra (about 400/ha), Most site-tenacious individuals were associated with tunnels in old stone walls that supported former agricultural terraces, Age was the only trait that explained site-tenacity in both sexes. The number of residents in each wall was positively related with wall length, and the sex-ratio of the residents was approximately 1:1 in every wall. Several animals spent all of the study period in the same area. Site tenacity is common among urodeles and particularly frequent among completely terrestrial species (Mathis et aI., 1995). In terrestrial habitats, animals may spend a significant part of their lives close to refuges that protect them from desiccation, such as burrows or objects at the surface. These may be occupied singly or in groups; in Plethodon einereus refuges form the core area of individual territories aggressively defended from intruders (Lang and Jaeger, 2000). Independence from the aquatic medium may have been influential for the evolution of site tenacity among urodeles-most species with lifelong site tenacity belong to the family Plethodontidae, where direct development allows independence from water bodies (Mathis et aI., 1995). There are far fewer examples of site tenacity in the family Salamandridae, a group which is thought to represent a basal modele lineage (Duellman and Trueb, 1986). Salamandrids depend on free water for development of their aquatic 1 Corresponding Author. E-mail: [email protected] . larvae, and usually engage in regular migrations to water bodies, where fertilization takes place. The exceptions to this pattern occur in only two genera, Salamandra and Mertensiella, where eggs develop inside uteri, and young are born either as advanced larvae (ovoviviparous populations of the genus Salamandra) or as fully metamorphosed juveniles (viviparous populations of the genus Salamandra and Mertensiella lusGhani;Zug, 1993). In the Fire Salamander, Salamandra salamandra (L), as in terrestrial plethodontids, courtship, spermatophore deposition and insemination occur on land (Arnold, 1987). Water bodies are only visited to give birth, which may take place in one to 10 episodes, in which case the whole parturition period may last more than one month (Rebelo,2002). We report results of a six-year capture-recapture study of individually marked Fire Salamanders living in an area with the highest recorded salamander densities in Portugal. The studied population belongs to the subspecies Salamandrasalamandragallaica;individuals may live up to 25 years, and reproduction typically starts at four years (Rebelo and Caetano, 1995). SHORTERCOMMUNICATIONS