Immobilisation of free-ranging Galapagos sea lions (Zalophus californianus wollebaeki).

Nine free-ranging Galápagos sea lions were immobilised for marking, using a combination of ketamine (3 to 5 mg per kg) and xylazine (0.5 to 1.0 mg per kg). The degree of effect depended largely on the animals' behavioural and physiological state before immobilisation (after parturition, high arousal, subject to aggression, etc.) All nine animals survived. Overheating in the immobilised state may quickly result in heart and circulatory failures.