Behavioral and Physiological Responses of Cheetah (<i>Acinonyx jubatus</i>) and Giraffe (<i>Giraffa camelopardalis</i> sp.) During After‐Hour Events at the Oregon Zoo

After-hours events are a popular way for modern zoos and aquariums to engage the local community, increase attendance, and generate additional income. Using fecal glucocorticoid metabolite (fGM), behavioral, and sound level monitoring, we analyzed whether cheetahs (Acinonyx jubatus) and giraffes (Giraffa camelopardalis sp.) showed any significant changes in response to three types of event "treatments" at the Oregon Zoo: (1) "concerts" with significantly elevated sound levels; (2) "other" evening events which constituted popular events with minimal sound disruptions, and (3) "control" when no evening events took place. We found significantly higher sound pressure levels in both habitats during "concert" event types with no significant differences between the remaining event types. Both cheetahs and giraffes exhibited subtle behavior changes during each event type, such as increased instances of "not visible" for cheetahs and a slight increase in the rate of "social interaction" for giraffes. However, no significant changes in fGM concentrations were measured for any individual animal across all the different event types. Yet there were some significant differences in fGM concentrations between the 2 years of data collection as well as some differences in fGM variability driven primarily by individual differences within each species. Results from this study, therefore, emphasize the highly individualistic nature of behavior and physiological responses to events of any type and illustrate how important it is to measure responses of each individual, when feasible, rather than focusing on an overall species typical response.