Occupancy, relative abundance, and activity patterns of great cu-rassow (crax rubra) in southeastern Mexico

The Great Curassow (Crax rubra) plays a key role in the regeneration of Neotropical forests through seed dispersal and predation of several plant species. Due to poaching, habitat loss, and fragmentation, C. rubra is globally at risk, and has become rare or locally extinct throughout of its range. Viable populations May occur in southeastern Mexico, particularly in Los Chimalapas region, in the state of Oaxaca, but this has not yet been verified. Recently, camera traps have been used for ecological studies of cracids, and other birds in the understory of rain forests. Our aim was to document the occupancy, relative abundance, and activity patterns of C. rubra in the understory of a tropical rain forest in Los Chimalapas region, through data gathered from camera traps. We gathered data from 27 camera traps and used occupancy models to analyze the effect of microhabitat on the detection (the probability that at least one individual of a species will be detected, given that the species inhabits the area of interest) and occupancy (the probability that a randomly selected site or sampling unit contains at least one individual of the species) probabilities. The best model indicated that C. rubra detection probability was higher in sites with higher records of a potential predator, the margay (Leopardus wiedii). The occupancy probability of C. rubra was 0.94 (SE = 0.06), and its detection probability ranged from 0.08 (station with zero records of L. wiedii) to 0.79 (stations with 27 records of L. wiedii). This association May be due to L. wiedii tracking the abundance of a potential prey (i.e., C. rubra) or because both species select sites with similar structural components of vegetation. Other models showed lower support, such as those models linking the presence of C. rubra to other predators and human presence. The species was mainly recorded as solitary individuals and showed more frequent activity in the morning and afternoon. The presence of chicks and juveniles suggest that there are suitable conditions for the establishment of a reproductive population of C. rubra in the region. Los Chimalapas still has connections with both, conserved (i.e., Selva El Ocote Biosphere Reserve) and highly deforested areas (i.e., the Uxpanapa region), and should be a priority region for C. rubra conservation.