In these datasets we provided information on the drinking behavior in 14 wild groups of brown howler monkeys (Alouatta guariba clamitans) inhabiting small, medium, and large Atlantic Forest fragments in southern Brazil. We provided two datasets: (1) full data on the drinking behavior of the 14 study groups, and (2) the dataset used to run the GLMMs described in the main manuscript. Overall, we found a wide variation in the mean rate of drinking among groups (range=0-16 records/day). Streams (44% of 1,258 records) and treeholes (26%) were the major types of water sources, followed by bromeliads in the canopy (16%), pools (11%), and rivers (3%). Further details in Chaves et al. (2021).

Data on drinking behavior of the fourteen howler groups was collected during periods ranging from 12 to 21 months, distributed in five year intervals: (i) January to December 1996 (group L5), (ii) June 2002 to August 2003 (group M1), (iii) January to December 2005 (groups S7, M2, and L4), (iv) June 2011 to June 2014 (groups S1, S2, S3, L1, L2, and L3), and (v) June 2018 to July 2019 (S4, S5, and S6). We collected data for all groups from dawn to dusk using high-resolution 10 x 42 binoculars.

We monitored the groups on a monthly basis during three to eight consecutive days in periods (i), (ii), and (iii), during four to five consecutive days on a bimonthly basis in period (iv), and during four to nine consecutive days on a monthly basis in period (v).