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In La Malinche Tlaxcala, Mexico, Penstemon roseus flowers when other floral re are scarce and when all eight hummingbird species recorded on the region are present, suggesting a high possibility of direct interspecific competition for the nectar resources. We-investigated temporal and spatial partitioning of hummingbirds foraging on this plant species over the flowering period. By measuring the availability and quality of nectar in several patches of Penstemon at different times, and counting the number of plants and flowers of each patch, we recorded the time until 1 hummingbird visited a plant within each patch. Likewise, we recorded the position of the visited flower on the plant as well as the position of the visited plant within the patch. We found temporal segregation among hummingbirds according to body size and territorial behavior during the most nectar-limited time. Hummingbird species differed in the times of day they visited flowers on this plant species, and both species and sexes differed in the location of flowers visited on plants. Subdominant species and females visited more flowers on the bottom of plants while dominant species and males preferred flowers on the tops of plants. Temporal and spatial segregation among hummingbirds is interpreted as adaptations to reduce risk of aggressive encounters. These behaviors may facilitate coexistence and allow hummingbirds to meet their short-term, energy demands. Accepted 18 December 2008.