Brown-headed Spider Monkey
Ateles geoffroyi fusciceps Gray, 1866
CR B1+2abcde, C2a

The brown-headed spider monkey was once distributed throughout the tropical forests on the Pacific side of the cordillera in western Ecuador, but today is known from only four localities in the northern part of its range in the province of Esmeraldas. One of its final strongholds is the Cotacachi-Cayapas Ecological Reserve, the largest area of remaining natural vegetation in the region, as well as the only protected area in which this spider monkey is known to occur.