Jon E. Swenson

Biomedical Protocols for Free-ranging Brown Bears, Gray Wolves, Wolverines and Lynx Editors

PREFACE Compilation of this document was initiated by the Norwegian Directorate for Nature Management in order to establish recommended protocols for capture, chemical immobilization, anesthesia and radiotagging of free-ranging brown bears (Ursus arctos), gray wolves (Canis lupus), wolverines (Gulo gulo) and Eurasian lynx (Lynx lynx). In addition, procedures to ensure proper sampling of biological materials for management, research and banking purposes have been included. The current protocols are based on nearly 3,000 captures of free-ranging brown bears, wolves, wolverines and lynx carried out from 1984 through 2012 in Scandinavia. Some of the results have been published as peer reviewed papers, conference presentations, theses, and reports. However, a large amount of data are still on file and will be published in the future. In addition, comprehensive reviews of the global literature on brown bears, wolves, wolverines and lynx have been carried out in order to include pertinent information from other sources. These protocols have been approved by all ongoing research projects on brown bears, wolves, wolverines and lynx in Scandinavia. We thank the contributors for their cooperative efforts. We also thank the Norwegian Directorate for Nature Management for their support.

FAMILY BREAKUP IN BROWN BEARS: ARE YOUNG FORCED TO LEAVE?

Abstract In brown bears (Ursus arctos), nursing of young >1 year of age has a positive effect on their growth rate but is energetically costly for mothers and reduces the number of litters a female can produce during her lifetime. We followed radiomarked families to study their behavior during the period of family breakup. Yearlings separated from their mothers during the mating season and most family breakups were associated with the presence of an adult male, suggesting that termination of maternal care was not initiated by offspring.

Seasonal changes in eicosanoid metabolism in the brown bear

Polyunsaturated fatty acids (PUFAs) exert several important functions across organ systems. During winter, hibernators divert PUFAs from oxidation, retaining them in their tissues and membranes, to ensure proper body functions at low body temperature. PUFAs are also precursors of eicosanoids with pro- and anti-inflammatory properties. This study investigated seasonal changes in eicosanoid metabolism of free-ranging brown bears (Ursus arctos). By using a lipidomic approach, we assessed (1) levels of specific omega-3 and omega-6 fatty acids involved in the eicosanoid cascade and (2) concentrations of eicosanoids in skeletal muscle and blood plasma of winter hibernating and summer active bears. We observed significant seasonal changes in the specific omega-3 and omega-6 precursors. We also found significant seasonal alterations of eicosanoid levels in both tissues. Concentrations of pro-inflammatory eicosanoids, such as thromboxane B2, 5-hydroxyeicosatetraenoic acid (HETE), and 15-HETE and 18-HETE, were significantly lower in muscle and/or plasma of hibernating bears compared to summer-active animals. Further, plasma and muscle levels of 5,6-epoxyeicosatrienoic acid (EET), as well as muscle concentration of 8,9-EET, tended to be lower in bears during winter hibernation vs. summer. We also found lower plasma levels of anti-inflammatory eicosanoids, such as 15dPGJ2 and PGE3, in bears during winter hibernation. Despite of the limited changes in omega-3 and omega-6 precursors, plasma and muscle concentrations of the products of all pathways decreased significantly, or remained unchanged, independent of their pro- or anti-inflammatory properties. These findings suggest that hibernation in bears is associated with a depressed state of the eicosanoid cascade.