Scientists don’t know very much about the Miller’s saki monkey (Pithecia milleri), so its precise range in South America, as well as its population size, is unknown. Fieldwork from scientists does tell us, however, that the Miller’s saki can be found in the tropical forests near the intersection of Colombia, Peru, and Ecuador.

The Miller’s saki is part of the Pithecia genus of monkeys. Species in this grouping are characterized as medium-sized monkeys that have long, coarse hair that puffs up (called piloerection) when they are approached in the wild, making them look bigger than they actually are. Hairs on their head are directed forward, like a hood. Both males and females have distinct throat glands for scent marking. They vocalize in grunts, chirps, whistles, and low calls. Their diet consists of mainly fruit and seeds, but they also eat insects, including army ants, spiders, and other arthropods.

The Miller’s sakis, like all South American primates, suffer from the effects of region-wide habitat disturbances, including fragmentation of their habitats and hunting. Sakis are hunted throughout their range for subsistence, pets, and for their body parts (some examples include skin for hats, tails for dusters, and as one researcher observed, “shrunken heads” as a tourist trade commodity in Ecuador).

More work is needed to better understand the Miller’s saki and the health of its population in the wild today so that it can be better protected.

  1. What is the purpose of piloerection in animals?

    • Answer

      Piloerection is an involuntary behavior where the hair of an animal straightens or bristles together to make the animal appear larger than it is. Scientists understand it to be a response to a threat.

  2. Why are saki monkeys in the genus Pithecia known as “flying monkeys”?

    • Answer

      This grouping of monkeys, which includes the Miller’s saki, is mainly arboreal, living in the forest trees. They do not have a prehensile tail that they would use to swing from tree branches, but they have been observed to take great leaps using their hind legs from one tree branch to another, giving them the appearance of flying.

  3. What is the name for animals that feed mainly on fruit or on seeds?

    • Answer

      Animals that feed mainly on fruits are called frugivores. Those that feed mainly on seeds are called granivores, or seed predators. Saki monkeys in the genus Pithecia are known to be mainly frugivores but also feed on seeds and insects.


invertebrate animal with a segmented body, exoskeleton, and jointed appendages.


breaking up of large habitats into smaller, isolated chunks. Fragmentation is one of the main forms of habitat destruction.


group of cells that secretes a chemical useful for the body to function.


environment where an organism lives throughout the year or for shorter periods of time.


involuntary bristling of hairs triggered by fright, cold, or shock.


total number of people or organisms in a particular area.

subsistence hunting

pursuit and kill of an animal for personal consumption, not sale.


existing in the tropics, the latitudes between the Tropic of Cancer in the north and the Tropic of Capricorn in the south.