Struttura e dinamica di popolazioni di Bombina pachypus nell’Appennino romagnolo.

Abstract. A study on three populations of Bombina pachypus was carried out in order to improve our knowledge on the biology of this threatened species in northeastern Apennines (Romagna region). In particular the authors provide the habitat description of three reproductive sites and the population estimate of the species through Capture-Mark-Recapture method. Three sites were monitored: (a) Sommorio(RA), consisting of three ponds, fed by a spring in a broad-leaf forest; (b) Monte Castellaccio (RA), two artificial cemented basins within an open grassland;(c) Ca’ di Veroli(FC), two ponds along the basin of a hill-stream which runs on a rocky bed through a broad-leaf forest. Surveys were carried out once a month during the activity season (April-October) for three years (2004, 2005, 2006). For each individual, photographs were made to the ventral pattern and biometric parameters were taken. The three populations resulted stable through the years; sex ratio is in favour of males; the growth was faster in young males though the first years, but adult females reached a larger SVL at the end of their development. Annual changes in water level appeared to be an important factor influencing the reproductive outcome and population size.