Behaviour
Verreaux's sifaka are diurnal and arboreal, and engage in sunbathing with outstretched arms and legs. Verreaux's sifaka move through the trees by clinging and leaping between vertical supports. They are capable of making remarkable leaps through the trees - distances of 9-10m are not uncommon. On the ground, they hop bipedally. They live in family groups, or troops, of 2-12, which may be just one male and female or multimale-multifemale. Group and population sex ratio can be more or less skewed toward males. Many groups seem to be effectively harem groups with a single dominant male unrelated with resident female(s). They have a home range of 2.8.5ha, and although they are territorial, it is the food source they will defend rather than the territory's boundaries, as often boundaries overlap. Females are dominant over males, forming a society using Matriarchy.
Females use anogenital secretion mainly for territory demarcation whereas males seem to use specialized secretions (via anogenital and throat glands) more for sexual "advertisement" than for territorial purposes. Males show bimorphism, by showing either clean or stained chest, deriving from throat gland secretion produced by throat glands and smeared on surfaces by rubbing the upper part of the chest. Stain-chested males are the most active marking, and chest staining seems to be related to testosteron levels.
Males and females were found to engage in a biological market, exchanging grooming for grooming during the non mating period, and grooming ("offered" by males) for reproductive opportunities (sexual access "offered" by females) during the mating period. A study found that females copulates more with stained-chested than with clean-chested males. On the other hand, clean-chested males, with a lower scent-releasing potential, usually offer more grooming to females. This “grooming for sex” tactic allows males with a clean chest to get to copulate with females, even if at low rate.
It has also been discovered that sifaka dyads often engage in post-conflict reunions after aggressive episodes: reconciliation occurs more frequently when food is not involved and for low intensity aggressions. In this species play behavior persists into adulthood where it is used, especially by stranger males during the mating period, as an ice-breaking mechanism to reduce xenophobia
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