Figure 1:

Number of studies including immunity parameters (orange), glucocorticoids (blue) or markers of oxidative stress (green) in view of conservation issues. The research was done in January 2014 by using Web of Knowledge and entering the following keywords: (i) “animal conservation” AND “animal population*” AND “immunity* OR immune*”; (ii) “animal conservation” AND “animal population*” AND “glucocorticoid* OR cortisol* OR corticosterone”; and (iii) “animal conservation” AND “animal population*” AND “oxidative stress* OR antioxidants*”. The upper panel represents the number of publications in each year, while the lower panel represents the relative contribution of each type of study.