Ecological correlates of a tick-borne disease, Anaplasma phagocytophilum, in moose in southern Norway

This is the postprint version of the article published in European Journal of Wildlife Research. The published version can be located at www.springerlink.comAs the distribution and abundance of ticks increase, so do the risks of tick-borne diseases. Anaplasma phagocytophilum, transmitted by Ixodes spp. ticks, is a widespread tick-borne infection causing tick-borne fever (TBF) in domestic ruminants and human granulocytic anaplasmosis. However, the role of wildlife in its epidemiology is poorly understood. Evidence of infection has been detected in wild cervids, but the pathogenicity and ecological consequences are unknown. We conducted a serological study of moose (Alces alces) in two populations in southern Norway, one where TBF was endemic (Telemark) and the other where sheep ticks (Ixodes ricinus) were essentially absent (Hedmark). Seroprevalence to A. phagocytophilum antibodies was 79 and 0 %, respectively. In Telemark, seroprevalence was significantly higher among females that calved successfully (85 %) than among others (50 %). Body mass and winter mass change were unrelated to serostatus. Relative abundance of questing ticks in Telemark was highest in deciduous forest and lowest in mature coniferous forest and higher at easterly aspects and altitudes below 350 m. Habitat factors associated with high tick abundance were risk factors for seropositivity among moose. Our findings were consistent with anaplasmosis causing a persistent subclinical infection in moose without population-level effects. Further work is needed to establish the importance of moose as a reservoir for the disease in sympatric domestic livestock

Retrospective growth analysis of the dwarf shrub Cassiope tetragona allows local estimation of vascular plant productivity in high arctic Svalbard

The work was supported financially by Research Council of Norway (POLARPROG grant 216051, “Reinclim”). AS was supported by the Norwegian Institute of Nature research.Peer reviewedPostprin

Culling calves

The article was published in the winter issue of Deer, the journal of the British Deer Society, 2010The shooting of calves or fawns can be a controversial matter. While in some countries the consensus among deer managers for the culling of calves is clear, it is often less clear exactly why. Jos Milner & Atle Mysterud examine the pros and cons

Is heavy browsing a threat to biodiversity in a boreal ecosystem?

Posteren ble presentert på Sustainable Conservation: Bridging the gap between disciplines i Trondheim 15.-18. mars 2010Herbivore numbers have been increasing across Europe and North America in recent decades, with implications for whole ecosystems including impacts on biodiversity. Moose populations in Scandinavia are no exception, leading to intense browsing of commercially important boreal forests. We examined the impact of moose browsing on species richness and abundance of 4 functional groups of plants (grasses, forbs, dwarf shrubs and canopy trees) and 2 functional groups of passerine birds (seed-eaters and insect-eaters) along a browsing gradient from sites of heavy browsing around supplementary feeding stations to light browsing at control sites. Both positive and negative effects were recorded

Experimental icing affects growth, mortality, and flowering in a high Arctic dwarf shrub

Acknowledgments This study was funded by the Research Council of Norway (POLARPROG grant 216051; SFF-III grant 223257/F50) and Svalbard Environmental Protection Fund (SMF grant 13/74). We thank Mathilde Le Moullec for helping with the fieldwork and the Norwegian Meteorological Institute for access to weather data.Peer reviewedPublisher PD

Effects of habitat selection & supplementary feeding on moose body weight & reproduction

Posteren ble presentert på 6th International Moose Symposium i Yakutsk, Russland 13-21 august 2008The effects of forage availability, winter supplementary feeding and habitat selection on moose body condition, reproductive rates and autumn slaughter weights are being studied in two locations in south-east Norway. GPS collared moose cows and their calves have been weighed and monitored in 2 years in the first study area and are currently being followed in the second study area. Preliminary results suggest that moose cows lose proportionally more weight over winter than calves and winter weight loss is lower in individuals using feeding stations, but only significantly so in the study area with a longer history of feeding and more severe winters. In the less snowy study area, cows using feeding stations only spent 30% of the winter within 500m of feeding stations and showed little difference in winter weight change or reproductive rate from individuals not using feeding stations. In the same study area, winter habitat selection differed slightly between users and non-users of feeding sites with users selecting less for spruce and deciduous stands. However, commercially important young pine stands were favoured by both groups of moose suggesting that supplementary feeding does not reduce forest damage. Moose using feeding sites concentrated space use around feeding stations, becoming central-place foragers. Data collection is on-going but we expect that the effects of supplementary feeding on habitat selection and ecological fitness will increase with the proportion of time spent at feeding stations, and hence be greater in severe winters and as the duration of the feeding programme increases

Demographic side effects of selective hunting in ungulates and carnivores

Selective harvesting regimes are often implemented because age and sex classes contribute differently to population dynamics and hunters show preferences associated with body size and trophy value. We reviewed the literature on how such cropping regimes affect the demography of the remaining population (here termed demographic side effects ). First, we examined the implications of removing a large proportion of a specific age or sex class. Such harvesting strategies often bias the population sex ratio toward females and reduce the mean age of males, which may consequently delay birth dates, reduce birth synchrony, delay body mass development, and alter offspring sex ratios. Second, we reviewed the side effects associated with the selective removal of relatively few specific individuals, often large trophy males. Such selective harvesting can destabilize social structures and the dominance hierarchy and may cause loss of social knowledge, sexually selected infanticide, habitat changes among reproductive females, and changes in offspring sex ratio. A common feature of many of the reported mechanisms is that they ultimately depress recruitment and in some extreme cases even cause total reproductive collapse. These effects could act additively and destabilize the dynamics of populations, thus having a stronger effect on population growth rate than first anticipated. Although more experimental than observational studies reported demographic side effects, we argue that this may reflect the quite subtle mechanisms involved, which are unlikely to be detected in observational studies without rigorous monitoring regimes. We call for more detailed studies of hunted populations with marked individuals that address how the expression of these effects varies across mating systems, habitats, and with population density. Theoretical models investigating how strongly these effects influence population growth rates are also required

Gastrointestinal nematodes of moose (Alces Alces) in relation to supplementary feeding

Winter supplementary feeding of wildlife is controversial because it may promote parasite and disease transmission by host aggregation. We investigated the effect of winter supplemental feeding of Scandinavian moose (Alces alces) on gastrointestinal (GI) parasite infection in two counties of southern Norway by comparing fecal egg counts of moose using, and not using, feeding stations between January 2007 and March 2010. We identified three different GI nematodes based on egg morphology. All three were found in Hedmark county while in Telemark county we found only Trichuris sp. (prevalence 33%). Prevalence of Trichostrongylidae (65%) and Nematodirus sp. (26%) in Hedmark was not affected by feeding station use. However, the probability of infection varied significantly between years sampled (Trichostrongylidae) and age class (Nematodirus sp.). Fecal egg counts (FEC), a proxy for intensity of infection, of Trichostrongylidae were higher in the year when winter weather conditions were more challenging and prevalence was higher, and decreased with increasing body mass. Adult moose had higher FECs than did juvenile moose, and female juveniles had lower abundances than did male juveniles. Use of feeding stations did not affect probability of infection with any of the nematodes or intensity of infection with Trichostrongylidae. We discuss our findings in terms of parasite life histories and recommend that parasitologic surveillance be included in the monitoring of feeding programs

Hunting moose or keeping sheep? - Producing meat in areas with carnivores

Artikkelen ble publisert i Alces i 2005 og du kan også finne artikkelen her: http://bolt.lakeheadu.ca/~alceswww/Vol41/Alces41_49.pdfMoose hunting is of considerable economic and social importance in much of Scandinavia. In some parts, such as south-east Norway, it is economically more important than sheep farming. We examine trends in moose harvesting and sheep production over a 12-year period in an area of increasing predator numbers and compare the meat yield before and after the re-establishment of wolves. The production of lamb meat at the county level declined, particularly from within the forest habitat, while the moose harvest showed only localized reductions. We also consider the scale of the economic loss caused by large carnivores and discuss management options for a future with carnivores

Long-term effects of supplementary feeding of moose on browsing impact at a landscape scale

This is the author's version before it was send to the publisher. Therefore it can differ slightly from the published version. For the published version, please go to: http://www.sciencedirect.com/science/article/pii/S0378112713007925Supplementary feeding of wildlife is a common management practice, increasingly used to reduce or divert herbivore impact from sensitive habitats, forestry or agriculture. The landscape-scale spatial distribution of herbivory in relation to supplementary or diversionary feeding stations is of particular relevance to wildlife and land management, yet has never been quantified. We considered multiple hypotheses, based on central-place foraging theory, to investigate how landscape-scale browsing impact changed as a function of distance from feeding stations and thereby test the effectiveness of diversionary feeding. We assessed the landscape-scale browsing impact of moose by quantifying browsing patterns and moose density in commercially-valuable young Scots pine stands in an area of south-east Norway with a long history of winter feeding. We also used positions from GPS-collared female moose to investigate the spatial distribution of individuals across the landscape. Moose density and browsing impact at a fine spatial scale (<1km) followed an exponential decrease with distance from diversionary feeding stations. However, at a landscape scale (1-10 km), browsing impact did not show any relationship with distance to feeding stations. Leader stem browsing on Scots pine trees was high at both the local (< 1 km; 68 ± 12 %) and landscape (1- 10 km; 56 ± 7 %) scales. In addition, browsing on commercially valuable Norway spruce, which is normally avoided by moose, was locally high around feeding stations. As currently practiced, long-term diversionary feeding of moose was ineffective in diverting browsing impact from young pine stands at the landscape scale. Browsing on commercially-important tree species was sufficiently high that economic consequences could be expected. To avoid further conflict, we suggest a combination of reducing the moose density and increasing the availability of natural or more attractive supplementary forage