Environmental enrichment affects adrenocortical stress responses in the endangered black-footed ferret

► Environmental enrichment lowers fecal glucocorticoid metabolites in captive juvenile male black-footed ferrets. ► Environmental enrichment increases fecal glucocorticoid metabolites in captive adult female black-footed ferrets. ► Fecal glucocorticoid metabolites have no impact on the incidence of disease or on the ability of black-footed ferrets to become reproductive. ► An environmental enrichment program may benefit captive juvenile male black-footed ferrets by reducing adrenocortical activity.