Verreaux's sifaka is a diurnal, social species existing in groups that are typically 5 members strong (4). These groups are mixed, and females appear to be dominant over males, who are the dispersive sex. The mating system is poorly understood, but in small groups only one female breeds each year. The season occurs in late January and early February and births are 6 months later; during the mating season males may fight between themselves for access to females (6). The single young develops rapidly, initially riding on its mothers belly and moving to her back after a month; young are fully independent at around 6 months of age (6). Groups inhabit home ranges that vary in size depending on the resources available; a core territory within this range is usually defended against neighbouring groups (6). Sifakas spend the majority of their time in the treetops, travelling via vertical clinging and leaping from one tree to the next (2). This method of locomotion can take them as far as 10 m in one leap (2). To cross open spaces they descend to the ground and adopt what looks like a skipping 'dance' on their hind legs with forearms outstretched for balance (2). The diet varies with season but encompasses a wide range of leaves, fruit, flowers and bark (3). Group members are vigilant for predator attacks, and aerial predators such as the Madagascar harrier-hawk (Polyboroides radiatus
) excite different calls than those for predators on the ground (6).