The Cacajao Program resulted from interviews with local inhabitants of the Alto Mayo Valley, conducted while studying the distribution of the San Martin titi monkey. The presence of the red uakary (Cacajao calvus ssp.), locally known as the mono cotulo and easy recognizable by its bald head and short tail, was reported to exist in the northern mountains of the Alto Mayo. Until then, this species was only known from the eastern lowlands of Peru, at a distance of more than 350 kilometers.
Further evidence was a picture provided by an American anthropologist, of an animal that was killed during a hunting party. Additionally we noticed in documents of the FERIAAM (Regional Federation of the Indigenous Awajun people from the Alto Mayo) pictures of indigenous people in traditional outfit, wearing head dresses made out of the skins of red uakaris.
With this evidence the research team of Proyecto Mono Tocón organised several expeditions and observed in 2010 a group of approximately 30 individuals of red uakaris (Cacajao calvus ssp.) in the Cahuapanas mountain range, North of the Alto Mayo Valley.
The discovery of this new population of uakaris, isolated from the eastern population and living in a completely different habitat, shows how little we know about primate distribution and taxonomy. The species is known to have a preference for palm fruits of the aguajales (Mauritia flexuosa). However, these palms grow especially in the lowlands, while we have observed the animals at 1500m altitude. It is possible that their distribution range extended in the past, before the arrival of humans, towards the swamp forests in the lowlands.
In 2013 we will conduct additional surveys to understand better the distribution of this population of mountain uakaris, and how it can be protected.