Factors affecting deer ked (Lipoptena cervi) prevalence and infestation intensity in moose (Alces alces) in Norway

Kent Rudi Bråten,Knut Madslien,Atle Mysterud,Bjørnar Ytrehus,Erling J Solberg,Hildegunn Viljugrein

doi:10.1186/1756-3305-5-251

Kent Rudi Bråten, Knut Madslien + Show 4 more

Open Access

https://doi.org/10.1186/1756-3305-5-251

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Abstract

BackgroundThe deer ked (Lipoptena cervi), a hematophagous ectoparasite of Cervids, is currently spreading in Scandinavia. In Norway, keds are now invading the south-eastern part of the country and the abundant and widely distributed moose (Alces alces) is the definitive host. However, key factors for ked abundance are poorly elucidated. The objectives of our study were to (i) determine deer ked infestation prevalence and intensity on moose and (ii) evaluate if habitat characteristics and moose population density are determinants of deer ked abundance on moose.MethodsIn order to identify key factors for deer ked abundance, a total of 350 skin samples from the neck of hunted moose were examined and deer keds counted. Infestation intensity was analyzed in relation to moose age and sex, moose population density and landscape characteristics surrounding the killing site.ResultsDeer ked infestation prevalence was 100%, but infestation intensity varied from 0.001 to 1.405 keds/cm2. Ked intensity was highest in male yearlings (~1.5 years) and positively associated with longitude and Scots pine (Pinus sylvestris) dominated habitat and negatively associated with bogs and latitude. Moose population density during autumn showed a tendency to be positively associated, while altitude tended to be negatively associated with ked intensity.ConclusionsDeer keds exploit the whole moose population within our study area, but are most prevalent in areas dominated by Scots pine. This is probably a reflection of Scots pine being the preferred winter browse for moose in areas with highest moose densities in winter. Ked intensity decreases towards the northwest and partly with increasing altitude, probably explained by the direction of dispersal and reduced temperature, respectively. Abundant deer ked harm humans and domestic animals. Moose management authorities should therefore be aware of the close relationship between moose, deer ked and habitat, using the knowledge as a management tool for locally regulating the ked burden.

Highlights

The deer ked (Lipoptena cervi), a hematophagous ectoparasite of Cervids, is currently spreading in Scandinavia
Ectoparasite infestation prevalence and level of infestation intensity Deer ked infestation prevalence was 100%
Despite different histories of colonization [6] and a higher density of definitive hosts in Norway compared to Finland [8], the deer ked is apparently an ectoparasite well-adapted to Fennoscandian moose and seems able to exploit the entire moose population within its distribution range

Summary

Introduction

The deer ked (Lipoptena cervi), a hematophagous ectoparasite of Cervids, is currently spreading in Scandinavia. In Norway, keds are invading the south-eastern part of the country and the abundant and widely distributed moose (Alces alces) is the definitive host. The deer ked (Lipoptena cervi) is a hematophagous ectoparasite of cervids in Europe, Asia, Africa and North-America [4]. In continental Europe, roe deer (Capreolus capreolus) is the most important, definitive host for deer keds [4], whereas in Norway, the abundant and widely distributed moose (Alces alces) [7] fill this role [8]. Hunters report that deer keds have become highly abundant on harvested moose in south-eastern Norway [6] These observations are further supported by people using forest areas for recreation, complaining about the increasing number of attacking keds during autumn. A severe outbreak of alopecia in moose was attributed to severe deer ked infestation in Norway and Sweden in 2006–2007 [9]

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