Abstract

While the question of whether the tiger (Panthera tigris) is a solitary or social organism in the wild remains unresolved, captive tigers are often co-housed with conspecifics. This study was undertaken to investigate whether age class or the number of conspecifics housed together in an enclosure had an effect on the stress of the tigers in the enclosure, as measured non-invasively by fecal glucocorticoid metabolite (“cortisol”) levels. Radioimmunoassay of immune-reactive fecal cortisol was performed on feces collected from fifteen tigers at two different facilities. Each tiger was classified by facility, age class (designated as greater or younger than 8 years of age), and social grouping (designated by number of co-housed conspecifics). There was no significant relationship between the number of tigers in an enclosure and the fecal glucocorticoid metabolite concentrations of the tigers within the enclosure. There was a significant difference in baseline fecal cortisol levels between the two facilities, as well as a significant difference between the two age classes, where higher levels occurred in the older tigers. The tigers at the facility that had higher fecal glucocorticoid metabolite levels are housed in close proximity to large interspecific carnivores, while the tigers at the facility with lower levels are only housed near other conspecifics, and have rotating access to a large enclosure. Under the specific husbandry conditions within this study, the number of tigers co-housed in an enclosure did not have a significant effect on the fecal glucocorticoid metabolite levels of the tigers within the enclosure.