Estimating costs and genetic benefits of various sizes of predator populations: The case of bear, wolf, wolverine and lynx in Sweden

Conservation of endangered species such as the “four big” predators in Sweden—bear (Ursus arctors), wolf (Canis lupus), wolverine (Gulo gulo) and lynx (Lynx lynx)—requires knowledge of the biological needs of the species. Information on the costs of meeting these needs is also of great importance. This paper describes an attempt to estimate such costs. The costs of various sizes of predator populations are seen in relation to their biological “value” in terms of genetic viability after a number of generations. Preliminary analysis indicated that the Swedish governmentʹs main expenditure on predators is in the form of compensation paid to owners of livestock killed by predators. Therefore, this study focuses on these costs alone. Historical data on compensation costs, predator populations, and, in some cases, reindeer populations, were used in regression analyses to estimate functions that could be used to predict the compensation costs of various sizes of predator populations. In order to check the plausibility of the regression functions, the maximum cost of the predatorsʹ manual meat consumption in terms of reindeer meat equivalents was estimated. The functions obtained from the regression analyses revealed that 500 effective individuals of each predator species would cost society 4 771 310 000 Swedish kronor (SEK) annually. A corresponding estimate based on the predatorsʹ maximum annual reindeer meat consumption gave an annual cost of SEK 594 730 000. Thus, the cost estimate based on the regression analyses may be discarded as implausible. The biological benefit of maintaining predator populations at these levels would be a maximum degree of inbreeding of 4–10% after 200 years. The conclusions drawn in this paper are not definitive, since there is some uncertainty in the underlying data. Improved knowledge of predator biology would be useful in future population management, both for ecologists and economists.