RELATIONSHIP BETWEEN GONADAL-STEROIDS AND CORTICOSTERONE DURING BLOOD-SAMPLING IN SAKER FALCONS

Blood sampling in manually restrained or ketamine (15 mg/kg given intr amuscularly) treated saker falcons (Falco cherrug) induced an increase d concentration in plasma corticosterone. Elevated plasma progesterone , oestradiol 17 beta, and testosterone concentrations also were observ ed in some of these birds. An inverse relationship was demonstrated be tween levels of corticosterone and progesterone, but not with the leve ls of other hormones. It is suggested that progesterone measurement sh ould be taken into consideration when studying the influence of stress ors in falcons.