Annual activity cycle of the Javeline sand Boa Eryx jaculus (Linnaeus, 1758) in Sicily.

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.