High Quality Content by WIKIPEDIA articles! High Quality Content by WIKIPEDIA articles! The Brown Spider Monkey or Variegated Spider Monkey (Ateles hybridus) is a critically endangered species of spider monkey, a type of New World monkey, from northern Colombia and north-western Venezuela. Its taxonomic history has been confusing, and in the past it has been treated as a subspecies of either the Geoffroy's Spider Monkey or the White-fronted Spider Monkey. Like all spider monkeys, it has very long, spindly limbs and a lengthy prehensile tail which can almost be called a fifth limb. The tail is made up of highly flexible, hairless tips with skin grooves which improves grip on tree branches and is adapted to its strictly arboreal lifestyle. The Brown Spider Monkey has a whitish belly and patch on the forehead, and - highly unusual among spider monkeys - the eyes are sometimes blue.