No abstract

Red harvester ant (Pogonomyrmex barbatus) inhabits deserts of USA and Mexico. Its activity patterns are well known in temperate deserts, but they have not been studied in tropical ones. We studied these patterns in the Tehucan Valley, a tropical desert in central Mexico. It had bimodal activity patterns in spring, summer, and fall while unimodal patterns in winter. These patterns differ from those reported for this species in temperate deserts where activity stopped in winter. Our results suggest that P. barbatus extends its activity periods and remains active all year round in the Tehuacan Valley.

In mammals, ecological interactions are difficult to observe directly, so they are usually inferred from co‐occurrence data. Direct interpretation of co‐occurrence patterns can be complicated since they may be the result of different processes such as habitat selection. We propose a logical framework along with multispecies occupancy models, to distinguish which process or interaction of processes gives rise to co‐occurrence patterns. We also used temporal kernel density estimates to explore the overlap in diel activity patterns, and ecological knowledge of the species as a complement to explain the drivers that generate co‐occurrence. To test our framework, we analyzed three mammal species: the bobcat (Lynx rufus), the gray fox (Urocyon cinereoargenteus), and their potential prey, the eastern cottontail rabbit (Sylvilagus floridanus), in a tropical dry habitat at Tehuacán‐Cuicatlán Biosphere Reserve, Mexico. Data were collected across 67 camera trap stations that operated from February to August 2018. The best‐fitted model described the spatial interaction between U. cinereoargenteus and L. rufus with S. floridanus; in both cases, the occupancy probability of the predatory species was higher in the presence of their prey than in their absence. Additionally, the three species presented a high overlap in their temporal activity patterns. Based on the knowledge of the species' ecology and our results, we identified that trophic interactions could be an important process shaping the co‐occurrence patterns of these species. In short, our framework highlights that it is possible to discern among the processes that influence the co‐occurrence patterns for species with well‐defined ecological roles, such as in our study system.

Densidad de puma (Puma concolor) y gato montés (Lynx rufus) en la Reserva de la Biosfera Tehuacán-Cuicatlán, México Puma (Puma concolor) and bobcat (Lynx rufus) density in Tehuacán-Cuicatlán Biosphere Reserve, Mexico