Risk of capture-related mortality in large free-ranging mammals: experiences from Scandinavia
Jon M. Arnemo, Per Ahlqvist, Roy Andersen, Finn Berntsen, Göran Ericsson, John Odden, Sven Brunberg, Peter Segerström & Jon E. Swenson
Arnemo, J.M., Ahlqvist, P., Andersen, R., Berntsen, F., Ericsson, G., Odden, J., Brunberg, S., Segerström, P. & Swenson, J.E. 2006: Risk of capture-related mortality in large free-ranging mammals: experiences from Scandinavia. - Wildl. Biol. 12: 109-113.
Chemical capture and anaesthesia of free-ranging mammals will always involve some risk of mortality even in healthy animals. Deaths may be directly or indirectly attributable to the anaesthetic event itself (e.g. drug overdose, drowning during induction and dart trauma) or may be caused by secondary effects from the capture (e.g. stress, myopathy, trauma or instrumentation with radio-transmitters). In long-term research projects on five major wildlife species in Scandinavia, the capture-related mortality rates (number of captures) were: moose Alces alces 0.7% (N = 2,816), brown bears Ursus arctos 0.9% (N = 1,079), wolverines Gulo gulo 2.8% (N = 461), Eurasian lynx Lynx lynx 3.9% (N = 380), and gray wolves Canis lupus 3.4% (N = 89). We suggest that wildlife professionals should strive for a zero mortality rate but adopt the standard that a mortality rate of > 2% probably should not be accepted in any large mammalian species. This can be achieved by: 1) using an experienced professional capture team, 2) developing and following a capture protocol specific to each species, and 3) requiring that a mortality assessment be undertaken after any capture-related death. This assessment should re-evaluate the capture protocol, including how changes in anaesthetics and methodological approaches could have prevented the mortality.
Key words: anaesthesia, capture protocols, free-ranging, immobilisation, mammal, mortality rates, standards
Jon M. Arnemo, Section of Arctic Veterinary Medicine, Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, NO-9292 Tromsø, Norway & Faculty of Forestry and Wilderness Management, Hedmark University College, Evenstad, NO-2480 Koppang, Norway - e-mail: jmarnemo@online.no
Per Ahlqvist, Grimsö Wildlife Research Station, Department of Conservation Biology, Swedish University of Agricultural Sciences, SE-73091 Riddarhyttan, Sweden - e-mail: per.ahlqvist@nvb.slu.se
Roy Andersen, Finn Berntsen & John Odden, Norwegian Institute for Nature Research, Tungasletta 2, NO-7485 Trondheim, Norway - e-mail addresses: roy.andersen@nina.no (Roy Andersen); finn.berntsen@nina.no (Finn Berntsen); john.odden@nina.no (John Odden)
Göran Ericsson & Peter Segerström, Department of Animal Ecology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden - e-mail addresses: goran.ericsson@szooek.slu.se (Göran Ericsson); peter@solbritt.se (Peter Segerström)
Sven Brunberg, Scandinavian Brown Bear Project, Noppikoski 156, SE-79498 Orsa, Sweden - e-mail: noppi@algonet.se
Jon E. Swenson, Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, PO Box 5003, NO-1432 Ås, Norway & Norwegian Institute for Nature Research, Tungasletta 2, NO-7485 Trondheim,Norway - e-mail: jon.swenson@umb.no
Corresponding author: Jon M. Arnemo
Received 25 September 2002, accepted 4 March 2005
Associate Editor: Harry V. Reynolds