The white-lipped peccary (Tayassu pecari) is a neotropical ungulate that forms some of the largest groups living in dense tropical forest. Populations of this species have declined throughout Mesoamerica during the last 50 years at alarming rates. Home-range and habitat preferences of this species have been documented in Brazil and Costa Rica for humid tropical forest. Here we studied home-range features and habitat preferences of white-lipped peccaries for a seasonally dry tropical forest of the Yucatan Peninsula—the Calakmul Biosphere Reserve—where water and food can be temporarily scarce or even absent. By using radiotelemetry and direct observations for 18 months of individuals in 4 groups, we documented some of the largest home ranges reported for some of the smallest group sizes documented for this species. Dry-season home ranges were constrained to the close vicinity of a few available water sources, whereas during the rainy season peccary groups were more mobile and traversed long distances. Compositional analyses of habitat preferences indicated that groups preferred ponds and Medium Sub-Perennial Forest in combination with Low Flooded Forest, whereas the least preferred was the Dry Forest. Apparently, the combination of ranging over large areas to access widely dispersed resources while living in smaller groups and sharing space allows white-lipped peccaries to survive in Calakmul.