Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2012
Authors
Panu Oulasvirta Paul Eric Aspholm Marko Kangas Bjørn Mejdell Larsen Pirko-Lisa Luhta Patric Olofsson Jouni TaskinenAbstract
No abstract has been registered
Abstract
No abstract has been registered
2011
Authors
Alexander Kopatz Hans Geir Eiken Paul Eric Aspholm Camilla Tobiassen Beate Banken Bakke Julia Schregel Tuomo Ollila Olga Makarova Natalia Polikarpova Vladimir Chizhov Snorre HagenAbstract
The trans-border brown bear population of Pasvik-Inari-Pechenga (Norway-Finland-Russia) has been monitored using genetic analyses of feces collection since 2005. In addition in 2007, hair traps were systematically placed out in the area to collect hairs for genetic analysis, to more precisely determine the minimum numbers of bears. In 2011, we repeated this hair trap study, using the exact same methodology as in 2007, to make a direct comparison of the results from the two years. Brown bear DNA was detected in 68 of 88 hair samples (77%) obtained from hair traps in 2011 and for 56 of these samples, a complete DNA profile could be determined. We identified 20 different bears in 2011, 12 females and 8 males. Only one bear was found in more than one country (Norway and Russia). We detected 11 bears in Norway, 7 bears in Finland and 3 bears in Russia in 2011. Four of these 20 bears were previously unknown, all four from Finland. A comparison of the results from 2007 and 2011 showed that we detected fewer bears in hair traps in 2011 (20 bears) than in 2007 (24 bears), but this modest difference may be coincidental. However, we observed a large drop in the yield of hair samples in the traps in 2011 compared to 2007 (88 versus 196 samples). This observation may be suggestive of some reduced activity of bears within the study area in 2011. In addition, only five (21%) of the bears caught in hair traps in 2007 were recaptured in 2011, which indicates a substantial turnover of individuals and may indicate that more frequent hair trapping monitoring would be beneficial to reliably track changes in the population. Additional samples (mainly scats) collected opportunistically in the field within the Russian and Finnish parts of the study area in 2011 detected four male bears in the Finnish part that had not been detected by hair traps. No additional samples from Norway were included to this study and any comparisons between the hair-trapping and opportunistic sampling at this point remains difficult. However, the results indicate that both methods combined are currently the most feasible methods to monitor brown bear numbers in an area.
Abstract
No abstract has been registered
Abstract
The protected brown bears (Ursus arctos) of Northern Europe are often involved in conflicts with humans, livestock depredation as well as subjected to illegal hunting. STR markers are the preferred forensic tools applied in wildlife crime cases and may be used for traceability and as tools for population management. Thus, a validated STR profiling system according to forensic standards is suggested. We have estimated allele frequencies and analysed repeat structure of 13 STR loci (G1D, G10B, Mu05, Mu09, Mu15, Mu26, G1A, G10L, Mu10, Mu23, Mu50, Mu51, Mu59) in 479 individuals of eight Northern European brown bear populations. STR analysis of hair- and faecal-samples (> 5000) collected in the field as well as tissue samples from shot bears (93) were used to genotype the individuals. The success rate for samples collected in the field was approximately 70%. Species specificity testing showed no false positive bear genotypes. These results show that hairs and faecal samples represent an excellent source for bear DNA that may be utilized to sample allele frequency estimates from living populations. For the eight different populations (four from Norway, one from Sweden and one from Finland and two from Northwest Russia) we have determined the observed and expected heterozygosities, departures from Hardy-Weinberg equilibrium, population substructures and probabilities of identity. Our results suggest that samples can be assigned to a particular individual if using a combination of ten or more of the validated markers in this brown bear DNA profiling system.
Authors
Ole Petter Laksforsmo Vindstad Snorre Hagen Jane Uhd Jepsen Lauri Teemu Kapari Tino Schott Rolf Anker ImsAbstract
Population cycles of the winter moth (Operophtera brumata) in sub-arctic coastal birch forests show high spatiotemporal variation in amplitude. Peak larval densities range from levels causing little foliage damage to outbreaks causing spatially extensive defoliation. Moreover, outbreaks typically occur at or near the altitudinal treeline. It has been hypothesized that spatiotemporal variation in O. brumata cycle amplitude results from climate-induced variation in the degree of phenological matching between trophic levels, possibly between moth larvae and parasitoids. The likelihood of mismatching phenologies between larvae and parasitoids is expected to depend on how specialized parasitoids are, both as individual species and as a guild, to attacking specific larval developmental stages (i.e. instars). To investigate the larval instar-specificity of parasitoids, we studied the timing of parasitoid attacks relative to larval phenology. We employed an observational study design, with sequential sampling over the larval period, along an altitudinal gradient harbouring a pronounced treeline outbreak of O. brumata. Within the larval parasitoid guild, containing seven species groups, the timing of attack by different groups followed a successional sequence throughout the moth’s larval period and each group attacked 1–2 instars. Such phenological diversity within parasitoid guilds may lower the likelihood of climate-induced trophic mismatches between victim populations and many/all of their enemies. Parasitism rates declined with increasing altitude for most parasitoid groups and for the parasitoid guild as a whole. However, the observed spatiotemporal parasitism patterns provided no clear evidence for or against altitudinal mismatch between larval and parasitoid phenology.
Authors
Jane Uhd Jepsen Lauri Teemu Kapari Snorre Hagen Tino Schott Ole Petter Laksforsmo Vindstad Arne Claus Nilssen Rolf Anker ImsAbstract
No abstract has been registered
2010
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered