A small monkey of forests in Bolivia, Peru and Brazil. It searches branches for insects and fruit.
It has short dense fur and a long tail. Pale areas surround the eyes and cheeks, contrasting with a dark muzzle.
In a captive colony of Bolivian squirrel monkeys, researchers tracked male behavior for a six-month period that spanned the time before, during and after the breeding season. The study included 10 adult males. Each lived as the only adult male in a breeding unit with 6–10 adult females and one juvenile male.
The researchers grouped 27 recorded responses into 11 behavioral clusters. Sexual activity peaked near the time when conceptions were most frequent; excitatory activity was initially high and declined through the breeding season, while maintenance activity did not change. Changes in the males’ social behavior were correlated with changing androgen levels. This was a captive study of adult males of the Bolivian subspecies.
IUCN Red List of Threatened Species · Least Concern (LC) · Global
The global IUCN assessment lists the species as Least Concern (LC), although it records a decreasing population trend and is marked as needing an update. The page displays 26 January 2015 as the latest assessment date. Brazil’s ICMBio also classified it as LC in an assessment published in 2025 (category date: 27 September 2019). It attributes the decline mainly to agriculture, cattle ranching, deforestation and expansion of roads and energy infrastructure, while judging that the identified threats do not put the population as a whole at risk of extinction in the near future.