Abstract

Moose Alces alces suffering from Moose Wasting Syndrome (MWS) have been observed in Sweden since 1985. In this study a population characterisation of MWS is done based on moose delivered to the National Veterinary Institute of Sweden during 1985-1989, public reports of non-traumatic moose deaths during 1991-1998, and radio-collared moose in one high- and one low-report frequency area. Moose suffering from MWS have been observed nationwide, but deaths from non-traumatic causes, including MWS, are most frequently reported from the county of Alvsborg. Nationwide reports of non-traumatic deaths peaked in 1992, but no peak was observed in Alvsborg. We suspect that the temporal as well as the spatial patterns observed were largely due to information about the MWS by the media, research activities and local concern. The age-specific mortality pattern of non-traumatic deaths did not differ, in either sex, between one high- and one low-report frequency area. The risk of dying from non-traumatic causes increased with moose age. Reports of female moose either suffering from MWS or having died from other non-traumatic causes largely outnumbered reports of males (1,349 and 387, respectively). Our results of age-specific risks suggest, however, that females are less vulnerable to non-traumatic mortality than males. The discrepancy between report frequencies and death risks is explained by the fact that the population sex ratio is female-biased (by sport harvest), and few males reach the age at which the risk of dying from non-traumatic causes increases. In the area from which most of the reports came the non-age-specific yearly risk of dying from non-traumatic causes, including MWS, was estimated to be 3.5% for females and 3.0% for males. Because there are other non-traumatic causes of death, the risk of dying from MWS exclusively is lower than our risk estimates indicate. There is no immediate risk of local extinction of moose due to MWS, as we estimate that the population would increase if culling was stopped.

Keywords

Alvsborg; death risk; disease; moose; Moose Wasting Syndrome (MWS); mortality; Sweden

Published in

Wildlife Biology
2002, Volume: 8, number: 3, pages: 219-228
Publisher: WILDLIFE BIOLOGY

SLU Authors

• Steen, Margareta

  • Department of Veterinary Microbiology, Swedish University of Agricultural Sciences
    

• Cederlund, Göran

  • Department of Conservation Biology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Pathobiology
Fish and Wildlife Management


Permanent link to this page (URI)

https://res.slu.se/id/publ/69805