The main risks for the conservation of wild non-human primates (NHP) in Costa Rica, Central America, are deforestation and the allocation of lands for agricultural activities. This is because these ecologically deleterious practices fragment continuous forests resulting in a mosaic of forest patches that differ in size and properties. Due to this, NHP, who are currently the vertebrates with the highest risk and rate of extinction, slowly adapt to this rapid environmental change, minimizing their metabolic costs to survive and reproduce. One way to balance these costs is to use forest patches depending on the benefits they provide, such as, food, shelter, or social contact. In order to understand the possible environmental factors that explain the usage of a series of 8 connected forest patches byAteles geoffroyi,Alouata paliatta, andSapajus imitatorwe collected demographic, climatological and other environmental data from 2018 until 2021. We used information-theory (i.e., AICc-based) model selection to identify the factors that best explained the presence/absence and behavior of the species of interest in the forest patches studied. Model-averaged estimates of the 2-best ranked models showed that monkey presence was highest in warmer, more humid days, especially when other groups were seen in the patch. Behavioral patterns were best explained by 4 best-ranked models and their averaged parameter estimates indicate that behavioral patterns were different in each path (0.12 ± 0.05; estimate ± SE). Furthermore, monkeys rested more often when other groups of the same species were present (0.94 ± 0.25), and foraged more during warmer (−0.06 ± 0.01), more humid days (−0.02 ± 0.001), and smaller groups (−0.14 ± 0.01). Our findings suggest that the usage of the 8 forest patches monitored by the 3 Atelid species studied depends on patch characteristics, not related to size nor the presence of a reserve, by the presence of other NHP in the patch and the meteorological conditions.