ANNUAL ACTIVITY CYCLE OF THE JAVELIN SAND BOA ERYX JACULUS (LINNAEUS, 1758) IN SICILY

Abstract

The Javelin sand Boa Eryx jaculus is a snake little known from an eco-ethological point of view. Here, some aspects of its phenology are described for the first time. 229 observations were collected in Sicily, with the aim of describing the annual activity of this population. The activity of adult males and juveniles presents a similar trend, with a sharp peak between May and July. Juveniles sharply declined in the following months. Adult females have three peaks of activity of similar amplitude. The activity cycle of the Javelin sand Boa could be modulated by some aspects of his trophic behaviour. In fact, juveniles and adult males prefer prey types highly available only during their maximum activity period. Adult females exploit prey with more constant availability over time and this could cause smaller fluctuations in the activity. Juveniles’ observations had a peak in the first half of their annual activity cycle, contrary to what might be expected in a species that gives birth mainly in late summer. This could indicate that the newborns have extremely elusive habits in the first months of life or, alternatively, the occurrence of births in spring has been rarely observed in other studies.