Annotations on the feeding ecology of black howler monkeys in an overcrowded fragment in Balancán, Tabasco, México. Wedescribed the feeding behavior of Central-American black howler monkey (Alouatta pigra) in a fragment of less than one hectare ofhumid evergreen forest surrounded by grassland for livestock use, isolated trees and mango orchards, in the region of Balancán (Tabasco,México). Objective: To record the diet and activity of black howler monkeys in crowded conditions during the wettest month in Balancán(Tabasco, México). Methods and methods: The behavioral observations (81 h) were made using the focal animal methodology withan A. pigra troop made up of three individuals (1 adult male, 1 adult female and 1 infant). Results: Feeding time represented 15.97%,rest 78% and locomotion 4.57% of total time. In the study area we recorded 14 plant species, with 10 being consumed by howlermonkeys. 55% of feeding time was devoted to the consumption of fruits, 27% to leaves, 17% to stems, and 1% to sprouts. Spondiasmombin was the tree species most consumed, with 61% of the time invested on it. Conclusion: Like other studies, we confirmed thefrugivore-folivore feeding tendency of the genus Alouatta. We provide information on the black howler monkey flexibility to live andmaintain themselves in extreme perturbation conditions, where their habitat is 0.1 ha with few tree species to use, forcing individualsto move around the ground.