The mammalian fauna of Madagascar is highly distinctive and largely endemic. The extant nonmarine, nonchiropteran taxa constitute (as of June 2014) 168 species, 40 genera and 9 families; of these, besides , endemic taxa make up all the species, all the genera, and all but one of the families. This endemic terrestrial fauna, consisting of , , and , is thought to have colonized the island from Africa via four (or five, if aye-ayes arrived separately) rafting events. The other historic terrestrial or semiterrestrial mammal group, the , is thought to have colonized the island possibly several times, perhaps via swimming.