Sound the stressor: how Hoatzins (Opisthocomus hoazin) react to ecotourist conversation

Exposure to ecotourists often disrupts animal behavior, which is known to contribute to heightened mortality rates. In the Amazon, the emblematic, communal nesting Hoatzin (Opisthocomus hoazin) is frequently pursued by tourists eager for close views. Such encounters may cause heightened stress levels, and egg or nestling predation due to decreased parental attendance to nests and nestlings. The effect of reducing conversational tourist noise near wildlife is poorly understood, but represents one potential mechanism of mitigating the impacts of ecotourists on wildlife. In this study, we approached Hoatzins by canoe, playing recorded tourist conversations at different volumes. Both the distances from which we observed Hoatzins becoming agitated (e.g., clucking, defecation, etc.) and flush (e.g., flight or climbing away) were positively correlated with volume. Within 10 weeks Hoatzins began to habituate to silent approaches. Tourist conversations, however, continued to elicit the same heightened disturbance responses throughout data collection. Therefore, to have the best chance of seeing Hoatzins at a short distance and minimizing potentially negative disturbances, ecotourists should cease all conversation. Although not tested, silence is probably the best strategy when looking for many wildlife species.