Snorre Hagen

Avdelingsleder/forskningssjef

(+47) 932 40 197
snorre.hagen@nibio.no

Sted
Svanhovd

Besøksadresse
Svanhovd, NO-9925 Svanvik

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Background The populations of brown bear (Ursus arctos) in northern Europe have been recovering or are in the process of recovery from a severe demographic bottleneck. Especially in the main popula- tions of Scandinavia and Finland, the number of individuals has been increasing substantially, compared to the population sizes estimated 20 years ago. Also, the populations have spatially expanded, putatively restoring connectivity and gene flow between these two, formerly separated populations. The Swedish Environmental Protection Agency (Naturvårdsverket) assigned a pro- ject to assess the connectivity and gene flow between the eastern and western parts of Fen- noscandia, Finland and Scandinavia. Objective Our objective was to detect possible immigration of brown bears from eastern Fennoscandia, specifically Finland, into Scandinavia. Material and Methods For the first time with continuous sampling of brown bears, we assessed the population genetic structure and gene flow between the brown bear populations of Scandinavia and Finland. We based our analyses on the dispersing sex, male brown bears, as females tend to be philopatric. Our target area was the county of Norrbotten in northern Sweden, at the border to Finland and Norway, representing the most likely area for potential eastern immigrants into Sweden. Previous research did not reveal any influx from Finland into Sweden. However, brown bear samples from Norrbotten have to a very limited degree been included in earlier studies on genetic connectivity in the area. In addition to a large number of samples from Norrbotten and northern Finland, we included genotypes sampled in regions surrounding the target area: Västerbotten in Sweden, Troms and Finnmark in Norway and southern Finland. We utilized all samples and genotypes from male bears available, and, also, genotyped recently collected samples of male brown bears from the study area. Analyses on population genetic structure and gene flow among regions were based on 924 individual male brown bear STR-genotypes (12 short tandem repeats or microsatellite markers). In order to reveal patterns of male dispersal and the distribution of male linages we used brown bear samples genotyped with nine Y-chromosomal STRs from 826 males. KEY WORDS : connectivity, european brown bear, Fennoscandia, Finland, male gene flow, migration, population genetic structure, Scandinavia, Ursus arctos NØKKELORD : europeisk brunbjørn, Fennoskandia, Finland, genflyt, konnektivitet, migrasjon, populasjons genetisk struktur, Skandinavia, Ursus arctos

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Habitat discontinuity, anthropogenic disturbance, and overharvesting have led to population fragmentation and decline worldwide. Preservation of remaining natural genetic diversity is crucial to avoid continued genetic erosion. Brown trout (Salmo trutta L.) is an ideal model species for studying anthropogenic influences on genetic integrity, as it has experienced significant genetic alterations throughout its natural distribution range due to habitat fragmentation, overexploitation, translocations, and stocking. The Pasvik River is a subarctic riverine system shared between Norway, Russia, and Finland, subdivided by seven hydroelectric power dams that destroyed about 70% of natural spawning and nursing areas. Stocking is applied in certain river parts to support the natural brown trout population. Adjacent river segments with different management strategies (stocked vs. not stocked) facilitated the simultaneous assessment of genetic impacts of dams and stocking based on analyses of 16 short tandem repeat loci. Dams were expected to increase genetic differentiation between and reduce genetic diversity within river sections. Contrastingly, stocking was predicted to promote genetic homogenization and diversity, but also potentially lead to loss of private alleles and to genetic erosion. Our results showed comparatively low heterozygosity and clear genetic differentiation between adjacent sections in nonstocked river parts, indicating that dams prevent migration and contribute to genetic isolation and loss of genetic diversity. Furthermore, genetic differentiation was low and heterozygosity relatively high across stocked sections. However, in stocked river sections, we found signatures of recent bottlenecks and reductions in private alleles, indicating that only a subset of individuals contributes to reproduction, potentially leading to divergence away from the natural genetic state. Taken together, these results indicate that stocking counteracts the negative fragmentation effects of dams, but also that stocking practices should be planned carefully in order to ensure long‐term preservation of natural genetic diversity and integrity in brown trout and other species in regulated river systems.

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Wild animal populations experience selection pressures from both natural and anthropogenic sources. The availability of extensive pedigrees is increasing along with our ability to quantify the heritability and evolvability of phenotypic traits and thus the speed and potential for evolutionary change in wild populations. The environment may also affect gene expressions in individuals, which may in turn affect the potential of phenotypic traits to respond to selection. Knowledge about the relationship between the genetic and environmental components of phenotypic variation is particularly relevant, given ongoing anthropogenically driven global change. Using a quantitative genetic mixed model, we disentangled the genetic and environmental components of phenotypic variance in a large carnivore, the brown bear (Ursus arctos). We combined a pedigree covering ~1,500 individual bears over seven generations with location data from 413 bears, as well as data on bear density, habitat characteristics, and climatic conditions. We found a narrow‐sense heritability of 0.24 (95% CrI: 0.06–0.38) for brown bear head size, showing that the trait can respond to selection at a moderate speed. The environment contributed substantially to phenotypic variation, and we partitioned this into birth year (5.9%), nonadditive among‐individual genetic (15.0%), and residual (50.4%) environmental effects. Brown bear head circumference showed an evolvability of 0.2%, which can generate large changes in the trait mean over some hundreds of generations. Our study is among the first to quantify heritability of a trait in a hunted large carnivore population. Such knowledge about the degree to which species experiencing hunting can respond to selection is crucial for conservation and to make informed management decisions. We show that including important environmental variables when analyzing heritability is key to understanding the dynamics of the evolutionary potential of phenotypic traits.

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Several non-invasive methods for assessing stress responses have been developed and validated for many animal species. Due to species-specific differences in metabolism and excretion of stress hormones, methods should be validated for each species. The aim of this study was to conduct a physiological validation of an 11-oxoaetiocholanolone enzyme immunoassay (EIA) for measuring faecal cortisol metabolites (FCMs) in male reindeer by administration of adrenocorticotrophic hormone (ACTH; intramuscular, 0.25 mg per animal). A total of 317 samples were collected from eight male reindeer over a 44 h period at Tverrvatnet in Norway in mid-winter. In addition, 114 samples were collected from a group of reindeer during normal handling and calf marking at Stjernevatn in Norway. Following ACTH injection, FCM levels (median and range) were 568 (268–2415) ng/g after two hours, 2718 (414–8550) ng/g after seven hours and 918 (500–6931) ng/g after 24 h. Levels were significantly higher from seven hours onwards compared to earlier hours (p < 0.001). The FCM levels at Stjernevatn were significantly (p < 0.001) different before (samples collected zero to two hours; median: 479 ng/g) and after calf marking (eight to ten hours; median: 1469 ng/g). Identification of the faecal samples belonging to individual animals was conducted using DNA analysis across time. This study reports a successful validation of a non-invasive technique for measuring stress in reindeer, which can be applied in future studies in the fields of biology, ethology, ecology, animal conservation and welfare.

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Gjennom det nasjonale overvåkingsprogrammet for rovvilt i Norge ble det i 2018 samlet inn prøver til DNA analyse med antatt opphav fra brunbjørn (Ursus arctos) for tiende år på rad. Av de 1007 prøvene som ble samlet inn i 2018, ble 984 prøver inkludert i den genetiske analysen (720 ekskrementprøver, 252 hårprøver og 12 vevsprøver) og 53 % var positive for brunbjørn. Totalt gav 447 prøver (45 %) en full DNA-identitet, og det ble fra disse prøvene påvist 138 ulike bjørner; 63 hunnbjørner og 75 hannbjørner. Dette er en økning på 10 % (13 individer) sammen-lignet med 2017, mens kjønnsfordelingen bare har endret seg med 2% i samme periode. Dette er det høyeste antallet brunbjørn registrert siden 2013, og det høyeste antallet hunnbjørn regi-strert siden overvåkningen startet i 2009. Forekomsten av brunbjørn er hovedsakelig konsentrert i fylkene Finnmark (49), Hedmark (44) og Trøndelag (32) som tidligere. Av det totale antallet bjørner påvist i 2018 er 59 % (81 individer) tidligere påvist i Norge, noe som utgjør en reduksjon i gjenfunn på 6 % i forhold til i fjor. Dette er den laveste andelen gjenfunn siden 2009. Om man inkluderer gjenfunn fra Sverige, Finland og Russland utgjør det totale antallet gjenfunn 87 indi-vider (63 %). Estimatet for 2018 på 7,7 ynglinger er det høyeste anslaget siden overvåkningen startet i 2009, og er en økning fra 2017 hvor estimatet lå på 6,9 ynglinger. I rovviltregion 5 (Hedmark) ligger antallet estimerte ynglinger i år, som i fjor, over bestandsmålet på 3 årlige ynglinger. De andre rovviltregionene ligger under bestandsmålet i 2018.

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Large terrestrial carnivores can sometimes display strong family bonds affecting the spatial distribution of related individuals. We studied the spatial genetic relatedness and family structure of female Eurasian lynx, continuously distributed in southern Finland. We hypothesized that closely related females form matrilineal assemblages, clustering together with relatives living in the neighboring areas. We evaluated this hypothesis using tissue samples of 133 legally harvested female lynx (from year 2007 to 2015), genotyped with 23 microsatellite markers, and tested for possible spatial genetic family structure using a combination of Bayesian clustering, spatial autocor ‐ relation, and forensic genetic parentage analysis. The study population had three potential family genetic clusters, with a high degree of admixture and geographic overlap, and showed a weak but significant negative relationship between pairwise genetic and geographic distance. Moreover, parentage analysis indicated that 64% of the females had one or more close relatives (sister, mother, or daughter) within the study population. Individuals identified as close kin consistently assigned to the same putative family genetic cluster. They also were sampled closer geographically than females on average, although variation was large. Our results support the possibility that Eurasian lynx forms matrilineal assemblages, and comparisons with males are now required to further assess this hypothesis.

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The apple fruit moth Argyresthia conjugella (Lepidoptera, Yponomeutidae) is a seed predator of rowan (Sorbus aucuparia) and is distributed in Europe and Asia. In Fennoscandia (Finland, Norway and Sweden), rowan fruit production is low every 2–4 years, and apple (Malus domestica) functions as an alternative host, resulting in economic loss in apple crops in inter-mast years. We have used Illumina MiSeq sequencing to identify a set of 19 novel tetra-nucleotide short tandem repeats (STRs) in Argyresthia conjugella. Such motifs are recommended for genetic monitoring, which may help to determine the eco-evolutionary processes acting on this pest insect. The 19 STRs were optimized and amplified into five multiplex PCR reactions. We tested individuals collected from Norway and Sweden (n = 64), and detected very high genetic variation (average 13.6 alleles, He = 0.75) compared to most other Lepidoptera species studied so far. Spatial genetic differentiation was low and gene flow was high in the test populations, although two non-spatial clusters could be detected. We conclude that this set of genetic markers may be a useful resource for population genetic monitoring of this economical important insect species.

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1. Large-scale pattern-oriented approaches are useful to understand the multi-level processes that shape the genetic structure of a population. Matching the scales of patterns and putative processes is both a key to success and a challenge. 2. We have developed a simple statistical approach, based on variogram analysis, that identifies multiple spatial scales where the population pattern, in this case genetic structure, have highest expression (i.e. the spatial scales at which the strength of patterning of isolation-by-distance (IBD) residual variance reached maximum) from empirical data and, thus, at which scales it should be studied relative to the underlying processes. The approach is applicable to any spatially explicit pairwise data, including genetic, morphological or ecological distance or similarity of individuals, populations and ecosystems. To exemplify possible applications of this approach, we analysed microsatellite genotypes of 1,530 brown bears from Sweden and Norway. 3. The variogram approach identified two scales at which population structure was strongest, thus indicating two different scale-dependent processes: home-rangerelated processes at scales <35 km, and subpopulation division at scales >98 km. On the basis of this, we performed a scale-explicit analysis of genetic structure using DResD analysis and compared the results with those obtained by the Bayesian clustering implemented in structure. 4. We found that the genetic cluster identified in central Scandinavia by Structure is caused by IBD, with distinct gene flow barriers to the south and north. We discuss possible applications and research perspectives to further develop the approach.

Sammendrag

Det nasjonale overvåkingsprogrammet for rovvilt i Norge har i 2017 samlet inn prøver med antatt opphav fra brunbjørn (Ursus arctos) for niende året på rad. Det ble totalt samlet inn 1034 prøver i 2017 (776 ekskrementprøver, 249 hårprøver og 9 vevsprøver) hvorav 59 % var positive for brunbjørn. Det ble påvist 125 ulike bjørner; 55 av dem var hunnbjørner og 70 var hannbjørner. Antall påviste bjørn er på nivå med forrige år (125 bjørner, 51 hunnbjørner og 74 hannbjørner), men kjønnsfordelingen viser en større andel hunner i år. Beregninger av antall ynglinger i 2017 ligger på 6,9 ynglinger, som er en svak økning i forhold til tidligere år. Forekomsten av brunbjørn er hovedsakelig konsentrert i fylkene Hedmark (48), Finnmark (37) og Nord-Trøndelag (29) som tidligere. I tillegg er det påvist hunnbjørner i Troms (4) og Nordland (1). Av det totale antallet bjørner påvist i 2017 er 66 % (82 individer) tidligere påvist i Norge, noe som utgjør en svak økning i gjenfunn i forhold til i fjor. Om man inkluderer gjenfunn fra Sverige, Finland og Russland utgjør det totale antallet gjenfunn 93 individer (74 %). DNA, brunbjørn, Ursus arctos, molekylær økologi, DNA profiler,overvåking, Norge, brown bear, molecular ecology, DNA profiles, monitoring, Norway

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Undersøkelse av antibiotikaresistensmarkørgenet neomycin fosfotransferase II (nptII) i prøver fra 12 ville arter fra Norge I et prosjekt fra Miljødirektoratet har vi testa for tilstedeværelse av nptII genet i 219 prøver fra 12 ulike ville arter fra hele Norge. Utvalget av prøver inkluderte planter (løvetann, rødkløver og markjordbær), insekter (skogmaur, rognebærmøll og liten høstmåler), snegl (brunsnegl), fisk (ørret og rognkjeks) og pattedyr (rødrev, brunbjørn og isbjørn). Vi brukte to ulike sanntids-PCR (Real-Time-PCR) tester for å undersøke fo tilstedeværelsen av kopier av nptII-genet i de 219 prøvene. Vi fant at nesten alle prøvene var negative (99%), mens kun tre enkeltprøver (løvetann, rødkløver og skogmaur) viste et svært lavt nivå av nptII (3-4 kopier). De positive prøvene kan være naturlige varianter eller kontaminering fra forskningslaboratorier. Vi konkluderer med at der er behov for utvida undersøkelser innenen for dette fagfeltet.

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The European winter moth, Operophtera brumata, is a non-native pest in the Northeastern USA causing defoliation of forest trees and crops such as apples and blueberries. This species is known to hybridize with O. bruceata, the Bruce spanworm, a native species across North America, although it is not known if there are hybrid generations beyond F1. To study winter moth population genetics and hybridization with Bruce spanworm, we developed two sets of genetic markers, single nucleotide polymorphisms (SNPs) and microsatellites, using genomic approaches. Both types of markers were validated using samples from the two species and their hybrids. We identified 1216 SNPs and 24 variable microsatellite loci. From them we developed a subset of 95 species-diagnostic SNPs and ten microsatellite loci that could be used for hybrid identification. We further validated the ten microsatellite loci by screening field collected samples of both species and putative hybrids. In addition to confirming the presence of F1 hybrids reported in previous studies, we found evidence for multi-generation asymmetric hybridization, as suggested by the occurrence of hybrid backcrosses with the winter month, but not with the Bruce spanworm. Laboratory crosses between winter moth females and Bruce spanworm males resulted in a higher proportion of viable eggs than the reciprocal cross, supporting this pattern. We discuss the possible roles of population demographics, sex chromosome genetic incompatibility, and bacterial symbionts as causes of this asymmetrical hybridization and the utility of the developed markers for future studies.

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We reconstructed family relationships, parent-child and siblings, among the brown bear (Ursus arctos) sampled in Sør-Varanger, Norway. Basis of this study are observed family relationships by the wildlife management. We compared this strong indication of relatedness with testing particular family relationships using SNP- and STR-genotype data of 154 brown bears sampled mainly non-invasively in the area from 2004 to 2016. We calculated likelihood ratios (LRs) and reconstructed family groups with the program FAMILIAS, which was used to reconstruct family relationships in human forensics. When the LR of each relationship, parent-child or siblings, was tested, 40 (38.1%) relationships were confirmed based solely on genetic data. The allele sharing analysis visualized as dendrograms supported that a large proportion of the remaining observed cases that were not confirmed as parent-child or siblings did share a closer family relationship. More detailed analysis is necessary to deduce the nature of these relationships (cousins, uncle-nephew etc.). Based on the genetic data we found, that the minimum number of cubs per year was on average 4.08. The applied SNP-chip has been developed on the Swedish brown bear population, a population different to the bears living in Sør-Varanger. The performance of the SNP-chip in this study rises questions of its applicability for family analysis in other brown bear populations and shows the need for further evaluation of the individual loci on the chip. Nevertheless, the combined SNP-data from all loci seems to provide power enough to detect the previously reported subpopulation structure. The observational data, sampling effort and quality of the sample material of the brown bears in Sør-Varanger is remarkable and the material provides an excellent testing ground to validate and improve the SNP-chip to reconstruct family groups.

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The number of effective breeders (Nb) and effective population size (Ne) are population parameters reflective of evolutionary potential, susceptibility to stochasticity, and viability. We have estimated these parameters using the linkage disequilibrium-based approach with LDNE through the latest phase of population recovery of the brown bears (Ursus arctos) in Finland (1993–2010; N = 621). This phase of the recovery was recently documented to be associated with major changes in genetic composition. In particular, differentiation between the northern and the southern genetic cluster declined rapidly within 1.5 generations. Based on this, we have studied effects of the changing genetic structure on Nb and Ne, by comparing estimates for whole Finland with the estimates for the two genetic clusters. We expected a potentially strong relationship between estimate sizes and genetic differentiation, which should disappear as the population recovers and clusters merge. Consistent with this, our ­estimates for whole Finland were lower than the sum of the estimates of the two genetic clusters and both approaches produced similar estimates in the end. Notably, we also found that admixed genotypes strongly increased the estimates. In all analyses, our estimates for Ne were larger than Nb and likely reflective for brown bears of the larger region of Finland and northwestern Russia. Conclusively, we find that neglecting genetic substructure may lead to a massive underestimation of Nb and Ne. Our results also suggest the need for further empirical analysis focusing on individuals with admixed genotypes and their potential high influence on Nb and Ne.

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We present data on the species composition of helminths in brown bears (Ursus arctos) from the Murmansk Region, Russia. The absence of any information about helminths of brown bear in the region necessitated the conduct of these studies. Samples were collected in 2014 and 2015 in the southern part of the Kola Peninsula from the White Sea coastal habitats. Annually, in the study area, 1–3 bears are legally hunted and biological samples for examination are very difficult to obtain. Therefore, we used fecal samples. We studied 93 feces and identified parasite eggs identified in 43 of them by morphometric criteria. The surveys revealed eggs of the following helminths: Dicrocoelium sp., Diphyllobothrium sp., Anoplocephalidae, Capillariidae, Baylisascaris sp., Strongylida 1, and Strongylida 2. These results represent the first reconnaissance stage, which allowed characterizing the taxonomic diversity and prevalence of parasites of brown bears of the Kola Peninsula.

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Aim Climatic changes during the Late Pleistocene had major impacts on populations of plant and animal species. Brown bears and other large mammals are likely to have experienced analogous ecological pressures and phylogeographical processes. Here, we address several unresolved issues regarding the Late Pleistocene demography of brown bears: (1) the putative locations of refugia; (2) the direction of migrations across Eurasia and into North America; and (3) parallels with the demographic histories of other wild mammals and modern humans. Location Eurasia and North America. Methods We sequenced 110 complete mitochondrial genomes from Eurasian brown bears and combined these with published sequences from 138 brown bears and 33 polar bears. We used a Bayesian approach to obtain a joint estimate of the phylogeny and evolutionary divergence times. The inferred mutation rate was compared with estimates obtained using two additional methods. Results Bayesian phylogenetic analysis identified seven clades of brown bears, with most individuals belonging to a very large Holarctic clade. Bears from the widespread clade 3a1, which has a distribution from Europe across Asia to Alaska, shared a common ancestor about 45,000 years ago. Main conclusions We suggest that the Altai-Sayan region and Beringia were important Late Pleistocene refuge areas for brown bears and propose large-scale migration scenarios for bears in Eurasia and to North America. We also argue that brown bears and modern humans experienced a demographic standstill in Beringia before colonizing North America.

Sammendrag

Det nasjonale overvåkingsprogrammet for rovvilt i Norge har i 2016 samlet inn prøver med antatt opphav fra brunbjørn (Ursus arctos) for åttende år på rad. Totalt ble det samlet inn 928 prøver i 2016 (680 ekskrementprøver, 240 hårprøver og 8 vevsprøver). Av disse prøvene var 67 % po-sitive for brunbjørn, og det ble påvist 125 ulike bjørner, hvorav 51 hunnbjørner og 74 hannbjør-ner. Dette er en svak nedgang sammenlignet med forrige år da det ble påvist 53 hunnbjørner og 75 hannbjørner. Beregninger av antall ynglinger i samme periode ligger relativt stabilt på ca. 6 ynglinger. Som tidligere år er forekomsten av brunbjørn i hovedsak konsentrert i fylkene Hed-mark (46), Finnmark (35) og Nord-Trøndelag (29). Av det totale antallet i 2016 er 63 % (79 indi-vider) tidligere påvist i Norge, noe som utgjør en noe lavere gjenfunnsandel enn forrige år. NØKKELORD : DNA, brunbjørn, Ursus arctos, molekylær økologi, DNA profiler, overvåking, Norge, DNA, brown bear, Ursus arctos, molecular ecology, DNA profiles, monitoring, Norway

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The potential for genetic contamination of stocks arising from translocation and subsequent release or escape of translocated and/or genetically mixed stocks may be a significant risk to wild populations. In this context, we undertook a population genetic survey of stocks of lumpfish (Cyclopterus lumpus) along the Norwegian coast to establish the existing genetic population structure, which will aid the development of policy of the species’ use as cleaner fish in salmonid aquaculture. This was done by using 14 microsatellite loci and 287 specimens collected at five fishing grounds, covering most of the Norwegian coastline from south to north, with additional 18 samples of first-generation reared fish from a fish farm outside Tromsø (North Norway). Overall, there was no indication of significant spatial genetic structuring or of positive correlation between geographic and genetic distance among the wild lumpfish samples. These results suggest that, should translocated individuals escape from aquaculture in Norway, this will probably have little to no impact on the genetic composition of the local fish population.

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The degree of gene flow within and among populations, i.e. genetic population connectivity, may closely track demographic population connectivity. Alternatively, the rate of gene flow may change relative to the rate of dispersal. In this study, we explored the relationship between genetic and demographic population connectivity using the Scandinavian brown bear as model species, due to its pronounced male dispersal and female philopatry. Thus, we expected that females would shape genetic structure locally, whereas males would act as genetic mediators among regions. To test this, we used eight validated microsatellite markers on 1531 individuals sampled noninvasively during country-wide genetic population monitoring in Sweden and Norway from 2006 to 2013. First, we determined sex-specific genetic structure and substructure across the study area. Second, we compared genetic differentiation, migration/gene flow patterns, and spatial autocorrelation results between the sexes both within and among genetic clusters and geographic regions. Our results indicated that demographic connectivity was not a reliable indicator of genetic connectivity. Among regions, we found no consistent difference in long-term gene flow and estimated current migration rates between males and females. Within regions/genetic clusters, only females consistently displayed significant positive spatial autocorrelation, indicating male-biased small-scale dispersal. In one cluster, however, males showed a dispersal pattern similar to females. The Scandinavian brown bear population has experienced substantial recovery over the last decades; however, our results did not show any changes in its large-scale population structure compared to previous studies, suggesting that an increase in population size and dispersal of individuals does not necessary lead to increased genetic connectivity. Thus, we conclude that both genetic and demographic connectivity should be estimated, so as not to make false assumptions about the reality of wildlife populations.

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1. There is a growing recognition of the importance of indirect effects from hunting on wildlife populations, e.g., social and behavioral changes due to harvest, which occur after the initial offtake. Nonetheless, little is known about how the removal of members of a population influences the spatial configuration of the survivors. 2. We studied how surviving brown bears (Ursus arctos) used former home ranges that had belonged to casualties of the annual bear hunting season in southcentral Sweden (2007-2015). We used resource selection functions to explore the effects of the casualty's and survivor's sex, age, and their pairwise genetic relatedness, population density, and hunting intensity on survivors' spatial responses to vacated home ranges. 3. We tested the competitive release hypothesis, whereby survivors that increase their use of a killed bear’s home range are presumed to have been released from intraspecific competition. We found strong support for this hypothesis, as survivors of the same sex as the casualty consistently increased their use of its vacant home range. Patterns were less pronounced or absent when the survivor and casualty were of opposite sex. 4. Genetic relatedness between the survivor and the casualty emerged as the most important factor explaining increased use of vacated male home ranges by males, with a stronger response from survivors of lower relatedness. Relatedness was also important for females, but it did not influence use following removal; female survivors used home ranges of higher related female casualties more, both before and after death. Spatial responses by survivors were further influenced by bear age, population density, and hunting intensity. 5. We have showed that survivors exhibit a spatial response to vacated home ranges caused by hunting casualties, even in non-territorial species such as the brown bear. This spatial reorganization can have unintended consequences for population dynamics and interfere with management goals. Altogether, our results underscore the need to better understand the shortand long-term indirect effects of hunting on animal social structure and their resulting distribution in space. Spatial response, kinship, competition, spatial reorganization, harvest, social structure

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Projections by the Intergovernmental Panel on Climate Change (IPCC) and sea ice forecasts suggest that Arctic sea ice will decline markedly in coming decades. Expected effects on the entire ecosystem include a contraction of suitable polar bear habitat into one or few refugia. Such large-scale habitat decline and fragmentation could lead to reduced genetic diversity. Here we compare genetic variability of four vagrant polar bears that reached Iceland with that in recognized subpopulations from across the range, examining 23 autosomal microsatellites, mitochondrial control region sequences and Y-chromosomal markers. The vagrants' genotypes grouped with different genetic clusters and showed similar genetic variability at autosomal microsatellites (expected heterozygosity, allelic richness, and individual heterozygosity) as individuals in recognized subpopulations. Each vagrant carried a different mitochondrial haplotype. A likely route for polar bears to reach Iceland is via Fram Strait, a major gateway for the physical exportation of sea ice from the Arctic basin. Vagrant polar bears on Iceland likely originated from more than one recognized subpopulation, and may have been caught in sea ice export during long-distance movements to the East Greenland area. Although their potentially diverse geographic origins might suggest that these vagrants encompass much higher genetic variability than vagrants or dispersers in other regions, the four Icelandic vagrants encompassed similar genetic variability as any four randomly picked individuals from a single subpopulation or from the entire sample. We suggest that this is a consequence of the low overall genetic variability and weak range-wide genetic structuring of polar bears – few dispersers can represent a large portion of the species' gene pool. As predicted by theory and our demographic simulations, continued gene flow will be necessary to counteract loss of genetic variability in increasingly fragmented Arctic habitats. Similar considerations will be important in the management of other taxa that utilize sea ice habitats.

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Det nasjonale overvåkningsprogrammet for rovvilt i Norge har i 2015 samlet inn prøver med antatt opphav fra brunbjørn (Ursus arctos) for syvende år på rad. Totalt ble det samlet inn 1 293 prøver i 2015 (860 ekskrementprøver, 422 hårprøver, 10 vevsprøver og 1 blodprøve). Av disse prøvene var 57 % positive for brunbjørn, og det ble påvist 128 ulike bjørner, hvorav 53 hunnbjørner og 75 hannbjørner. Dette er en reduksjon sammenlignet med forrige år da det ble påvist 54 hunnbjørner og 82 hannbjørner, og er også det laveste antallet registrert de siste syv årene. Over samme periode har andelen hunnbjørner økt, og var i 2015 andelen økt til 41 %. Beregninger av antall ynglinger i samme periode ligger relativt stabilt på ca. 6 ynglinger. Som tidligere år er forekomsten av brunbjørn i hovedsak konsentrert i fylkene Finnmark (49), Hedmark (43) og Nord-Trøndelag (19). Av det totale antallet i 2015 er 70 %( 89 individer) tidligere påvist i Norge, noe som utgjør omtrent samme gjenfunnsandel som forrige år.

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Brunbjørn bestanden I Pasvikdalen I Sør Varanger I Finnmark har vært overvåket med feltinnsamling av ekskrementer og hår til DNA analyse siden 2005. I 2007, 2011 og 1015 ble hårfeller systematisk plassert i det trilaterale grenseområdet i Pasvik (Norge), Enare (Finland) og Pechenga (Russland) for å bestemme mer presist et minimum antall bjørner. Vi har i 2016 brukt nøyaktig den samme metodologien med 20 hårfeller i et 5 km x km rutenett i de nordlige delene av Pasvikdalen. Dette området har ikke før vært undersøkt systematisk med hårfeller. I løpet av 2 måneder (juniaugust) samlet vi inn 77 hårprøver og identifiserte 10 ulike brunbjørner (6 hoer og 4 hanner). Av disse var det 5 bjørner som var påvist i tidligere års DNA overvåkning, mens 5 bjørner (4 hoer og 1 hann) ble påvist for første gang i dette prosjektet.

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Med bruk av 12 hårfeller ble det identifisert to ulike bjørn i kalvingslandet til reinbeitedistrikt 5A/5C i perioden fra 21. april til slutten av juni 2016. Data fra e- bjeller (Findmysheep), som ble båret av 100 simler, indikerte hvordan reinen brukte området i denne perioden. Ingen av de to bjørnene er kjent fra dette området før, og ingen av bjørnene som var kjent fra området i 2013, 2014 eller 2015 ble påvist i år.

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The autumnal moth (Epirrita autumnata) is a cyclically outbreaking forest Lepidoptera with circumpolar distribution and substantial impact on Northern ecosystems. We have isolated 21 microsatellites from the species to facilitate population genetic studies of population cycles, outbreaks, and crashes. First, PCR primers and PCR conditions were developed to amplify 19 trinucleotide loci and two tetranucleotide loci in six multiplex PCR approaches and then analyzed for species specificity, sensitivity and precision. Twelve of the loci showed simple tandem repeat array structures while nine loci showed imperfect repeat structures, and repeat numbers varied in our material between six and 15. The application in population genetics for all the 21 microsatellites were further validated in 48 autumnal moths sampled from Northern Norway, and allelic variation was detected in 19 loci. The detected numbers of alleles per locus ranged from two to 13, and the observed and expected heterozygosities varied from 0.04 to 0.69 and 0.04 to 0.79, respectively. Evidence for linkage disequilibrium was found for six loci as well as indication of one null allele. We find that these novel microsatellites and their multiplex-PCR assays are suitable for further research on fine- and large-scale population-genetic studies of Epirrita autumnata. tri- and tetranucleotide microsatellites; multiplex PCR; Lepidoptera; population genetics

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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 and 2011, 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 the area. In 2015, we repeated this hair trap study, using the exact same methodology as in 2007 and 2011, to make a direct comparison of the results from all the 3 study years. Brown bear DNA was detected in 158 of 209 hair samples (76%) obtained from hair traps in 2015 and for 136 of these samples, a complete DNA profile could be determined. We identified 26 different bears in 2015, 17 females and 9 males. We detected 16 bears in Norway, 5 bears in Finland and 9 bears in Russia. Thirteen of these 26 bears were previously unknown, 7 were detected in Norway, 2 in Finland and 4 in Russia. A comparison to the results from 2007 and 2011 showed that we detected more bears in hair traps in 2015 (26 bears) than in 2007 (24 bears) and 2011 (20 bears). We observed an increase in the total yield of hair samples in the traps in 2015 (209 samples) compared to 2007 (196 samples) and 2011 (88 samples). Four (16%) and seven (35%) of the bears caught in hair traps in 2007 and in 2011, respectively, were also recaptured in 2015. Additional samples (scats and hair) collected opportunistically in the field within the Russian and Finnish parts of the study area in 2015 detected 4 male bears and 1 female bear in the Russian part leading to a total of 14 bears identified in Russia, of which 8 bears were detected for the first time. Additional scat and hair samples from the field in Norway were not included in our study and comparisons between the systematic hair-trapping and opportunistic sampling in the field were not performed. However, the results indicate that both methods combined are currently the optimal approach to monitor brown bear numbers in an area.

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I 2014 ble det for sjette år på rad samlet inn prøver med antatt opphav fra brunbjørn (Ursus arctos) gjennom det nasjonale overvåkingsprogrammet for rovvilt i Norge. Det ble samlet inn 962 prøver i 2014 (703 ekskrementprøver, 247 hårprøver, 11 vevsprøver og 1 blodprøve), noe som er betydelig lavere antall prøver enn forrige år (1246 prøver i 2013). Av disse prøvene var 60 % positive for brunbjørn, og det ble påvist 136 ulike bjørner, hvorav 54 hunnbjørner og 82 hannbjørner. Dette er en reduksjon sammenlignet med forrige år da det ble påvist 55 hunnbjørner og 93 hannbjørner. I løpet av de siste seks årene har andelen hunnbjørner økt, og i 2014 var andelen økt til 40 %. Beregninger av antall ynglinger i samme periode ligger relativt stabilt på ca. 6 ynglinger. Som tidligere år er forekomsten av brunbjørn i hovedsak konsentrert i fylkene Hedmark (43), Finnmark (34) og Nord-Trøndelag (29). Av de 136 individbestemte bjørnene i Norge i 2014 var 93 individer (68 %) tidligere påvist i Norge, noe som utgjør omtrent samme gjenfunnsandel som forrige år. DNA, brunbjørn, Ursus arctos, DNA profiler, overvåking, Norge, DNA, brown bear, Ursus arctos, DNA profiles, monitoring, Norway

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Ved bruk av 10 hårfeller ble det påvist 5 ulike bjørn i kalvingslandet til reinbeitedistrikt 5A/5C fra 15 april til slutten av juni 2015. Det ble også observert individer og sportegn av jerv, gaupe og kongeørn i kalvingslandet. Dataene fra radio-bjeller (Telespor) og e-bjeller (Findmysheep) som ble båret av henholdsvis 20 og 100 simler, indikerte hvordan reinen brukte området og det er også at det er mulig å tolke bevegelsesmønstre og bevegelseshastigheter hos simlene i relasjon til rovdyrene. Ingen av de fem bjørnene var kjent fra området tidligere år og på den andre siden ble det ikke påvist noen av bjørnene som var kjent fra området i 2013 og 2014.

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High-resolution Y-chromosomal markers have been applied to humans and other primates to study population genetics, migration, social structures and reproduction. Y-linked markers allow the direct assessment of the genetic structure and gene flow of uniquely male inherited lineages and may also be useful for wildlife conservation and forensics, but have so far been available only for few wild species. Thus, we have developed two multiplex PCR reactions encompassing nine Y-STR markers identified from the brown bear (Ursus arctos) and tested them on hair, fecal and tissue samples. The multiplex PCR approach was optimized and analyzed for species specificity, sensitivity and stutter- peak ratios. The nine Y-STRs also showed specific STR-fragments for male black bears and male polar bears, while none of the nine markers produced any PCR products when using DNA from female bears or males from 12 other mammals. The multiplex PCR approach in two PCR reactions could be amplified with as low as 0.2 ng template input. Precision was high in DNA templates from hairs, fecal scats and tissues, with standard deviations less than 0.14 and median stutter ratios from 0.04 to 0.63. Among the eight di- and one tetra-nucleotide repeat markers, we detected simple repeat structures in seven of the nine markers with 9–25 repeat units. Allelic variation was found for eight of the nine Y-STRs, with 2–9 alleles for each marker and a total of 36 alleles among 453 male brown bears sampled mainly from Northern Europe. We conclude that the multiplex PCR approach with these nine Y-STRs would provide male bear Y-chromosomal specificity and evidence suited for samples from conservation and wildlife forensics.

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Knowledge on the number of female brown bears, especially reproducing females, is important for the wildlife management. One of the largest and densest populations of brown bears in Norway is located in Sør-Varanger, Finnmark, Northern Norway. Observations of females with cubs are reported regularly in the region. Information on the relatedness among individuals is often unknown as well as specifics on the number of reproductions and relatedness among females within this population. We have utilized genetic data originating from feces and hair samples collected in Sør-Varanger in the years 2004-2014 to investigate female brown bear localities. In the same period, personnel from the Norwegian State Nature Inspectorate (SNO) have observed 9 female brown bears with potential female cubs (a priori probability of 0.5). Sampling areas of those female brown bears and their potential offspring showed substantial geographical vicinity suggesting overlapping home ranges. We then calculated the likelihood ratios for these relationships using the forensic software Familias for 18-mother-female cub relationships. For 10 of 18 such relationships, the genetic relationship between mother and female cub were confirmed as their observation in the field was suggestive of. Of the initially observed 9 female bears, 6 have produced 10 female cubs, which here could be confirmed by genetic methods. The remaining 3 females were not excluded to be mothers to their potential cubs, but these relationships cannot be confirmed without additional DNA analyses. Another family relationship could also be confirmed between two observed female bears, but the type of relationship could not be determined.

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I 2013 ble det for femte år på rad samlet inn prøver med antatt opphav fra brunbjørn (Ursus arctos) gjennom det nasjonale overvåkingsprogrammet for rovvilt i Norge. Av de 1222 prøvene som ble samlet inn i 2013 var 806 prøver (66 %) positive for brunbjørn. DNA-analyse av 1222 prøver (907 ekskrementprøver, 310 hårprøver og 5 vevsprøver) påviste 147 ulike bjørner, hvorav 55 hunnbjørner og 92 hannbjørner. Undersøkelsen viser en økning i forhold til forrige år av både hunnbjørner (55 mot 51) og hannbjørner (92 mot 86). DNA-resultatene gav et estimat på ca. 7 ynglinger i 2013, noe som indikerer en liten økning fra forrige år der estimatet var på ca. 6. Hedmark er det fylket som viser tydeligst en liten økning når det gjelder ynglinger. Av de 147 individene var 96 (65 %) tidligere påvist i Norge, noe som er en betydelig nedgang i antall gjenfunn sammenlignet med tidligere år. Som før ble flest bjørner påvist i fylkene Finnmark (50), Hedmark (40) og Nord-Trøndelag (32). DNA, brunbjørn, Ursus arctos, DNA profiler, overvåking, Norge, DNA, brown bear, Ursus arctos, DNA profiles, monitoring, Norway

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Genetic methods based on sampling of feces and hairs to study brown bears have become the method of choice for many wildlife researchers and managers. Feces and hairs are the most common sample material for DNA identification of individual bears. While the collection of feces and hairs in the field is carried out in an opportunistic manner, hair-trapping can be applied systematically at specific locations. We have here tested a novel systematic method based on hair sampling on power poles. The method relies on the specific behavior of bears to mark, scratch, bite and scrub on power poles, and by this also leave some hairs behind. During late summer and autumn we have investigated 215 power poles in the Pasvik Valley and sampled 181 hair samples in 2013 and 57 in 2014. A total of 17.3% of the samples collected in 2013 and 12.3% in 2014 were positive on brown bear DNA. Our success rates are comparable to other studies, however, DNA quality/content in the hair samples was generally low. Based on other studies, the method could be improved by sampling during spring and early summer and to use shorter frequencies of 2 to 4 weeks between each sampling. Based on our results and previous studies, we can conclude that this sampling technique should be improved by the development of a more accurate and frequent sampling protocol. Hair sampling from power poles may then lead to improved potential to collect valuable samples and information, which would be more difficult to collect otherwise.

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Human–bear conflicts occur frequently in the Pasvik Valley, Norway. We used a variantof the hair-trapping method with higher densities of traps (2.5 x 2.5 km grid) todetect brown bears moving near human settlements and livestock. We distributed 20hair traps for one month close to a farm with frequent observations of grazing bears.The study area consisted of one area close to the farm, and one adjacent area withoutsettlements. We collected 85 hair samples and identified 13 different individuals bySTR analysis. In the farm area, we detected 4 different males once, and a female thatwas detected in both areas. In comparison, nine bears (2 males and 7 females) weredetected for more than one week in the area without settlements, suggesting lowerroaming activity. Conclusively, hair trapping has the potential to survey bears at specificlocations of importance to the wildlife management.

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Two related issues in studies of biological invasions are how quickly the enemy complexes of invasive species become as species-rich and efficient as those of native species and how important enemy release is for the establishment and spread of invaders. We addressed these issues for the geometrid moths Operophtera brumata and Agriopis aurantiaria, who invaded the coastal mountain birch forest of northern Norway by range expansion approximately a century and 15 years ago, respectively. This was done by comparing larval parasitoid species richness and prevalence among the invaders and the native geometrid Epirrita autumnata. We found that E. autumnata and O. brumata both hosted seven parasitoid species groups, whereas A. aurantiaria hosted only one. Several parasitoid groups were shared between two or more of the geometrids. Total larval parasitism rates were similar in all three geometrid species, and comparison with published studies on larval parasitism in Western Europe suggested that O. brumata and A. aurantiaria do not suffer lower parasitism rates in our study region than in their native ranges. Our results indicate that accumulation of larval parasitoids on invasive geometrids in coastal mountain birch forest may reach completion within a few decades to at least a century after the invasion, and that establishment and spread of such invaders is unlikely to be facilitated by release from larval parasitism. Our investigations also uncovered a high degree of spatiotemporal synchrony between the total larval parasitism rates of O. brumata and A. aurantiaria, suggesting that larval parasitism of different geometrid species in the study system is governed by some common external factor

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I 2012 ble det for fjerde år på rad samla inn prøver med antatt opphav fra brunbjørn (Ursus arctos) gjennom det nasjonale overvåkingsprogrammet for rovvilt i Norge. Av de 1395 prøvene som ble samla inn i 2012 var 748 (54 %) prøver positive for brunbjørn, noe som utgjør en nedgang i andelen positive prøver i forhold til tidligere innsamlinger (63-68 % positive prøver). DNA analyse av 1395 prøver (1048 ekskrement prøver, 333 hårprøver og 14 vevsprøver) påviste 137 ulike bjørner, der 51 var hunnbjørner. Antallet hunnbjørner er det samme som forrige år, og basert på DNA resultatene er det mulig å estimere ca. 6 ynglinger i 2012. Resultatet viser en nedgang i antallet hannbjørner fra 100 til 86. Av de 137 individene var 106 (77 %) tidligere påvist i Norge. Som tidligere ble flest bjørner påvist i fylkene Finnmark (49), Hedmark (37) og Nord-Trøndelag (30). For disse tre fylkene er resultatene i 2012 svært like i forhold til tidligere år, også når det gjelder antallet hunnbjørner med hhv. 26, 12 og 11 hunnbjørner. DNA, brunbjørn, Ursus arctos, DNA profiler, overvåking, Norge, DNA, brown bear, Ursus arctos, DNA profiles, monitoring, Norway

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Outbreaks of geometrid defoliators in subarctic birch forest in Fennoscandia often occur at high altitude in a distinct zone along the tree line. At the same time, moth larvae may not have an impact on the forest at lower altitude. Directly adjacent outbreak and nonoutbreak areas offer unique opportunities for studying the underlying mechanisms of outbreaks. Within two altitudinal gradients in coastal northern Norway, we investigated whether altitudinal outbreaks might be caused by release from pupal predation by ground-dwelling invertebrates such as harvestmen (Opiliones), spiders (Araneae), rove beetles (Coleoptera: Staphylinidae), carabid beetles (Coleoptera: Carabidae), and other beetles (Coleoptera). We predicted a consistently higher abundance of such generalist predators at low versus high altitudes. Our results did not support this prediction. There was no consistent altitudinal variation in the abundance of predators that could be related to zonal moth outbreaks in the birch forest slopes. In addition, none of the predator groups investigated showed any numerical response to a distinct outbreak of winter moth that took place during the course of the study. Consequently, localised moth outbreaks at the altitudinal tree line in northern Norway cannot be explained by the release from pupal predation by the predator groups examined here.

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Insect outbreaks in northern-boreal forests are expected to intensify owing to climate warming, but our understanding of direct and cascading impacts of insect outbreaks on forest ecosystem functioning is deficient. The duration and severity of outbreaks by geometrid moths in northern Fennoscandian mountain birch forests have been shown to be accentuated by a recent climatemediated range expansion, in particular of winter moth (Operophtera brumata). Here, we assess the effect of moth outbreak severity, quantified from satellite-based defoliation maps, on the state of understory vegetation and the abundance of key vertebrate herbivores in mountain birch forest in northern Norway. We show that the most recent moth outbreak caused a regional-scale state change to the understory vegetation, mainly due to a shift in dominance from the allelopathic and unpalatable dwarf-shrub Empetrum nigrum to the productive and palatable grass Avenella flexuosa. Both these central understory plant species responded significantly and nonlinearly to increasing outbreak severity. We further provide evidence that the effects of the outbreak on understory vegetation cascaded to cause strong but opposite impacts on the abundance of the two most common herbivore groups. Rodents increased with defoliation, largely mirroring the increase in A. flexuosa, whereas ungulate abundance instead showed a decreasing trend. Our analyses also suggest that the response of understory vegetation to defoliation may depend on the initial state of the forest, with poorer forest types potentially allowing stronger responses to defoliation

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Noninvasively collected genetic data can be used to analyse large-scale connectivity patterns among populations of large predators without disturbing them, which may contribute to unravel the species’ roles in natural ecosystems and their requirements for long-term survival. The demographic history of brown bears (Ursus arctos) in Northern Europe indicates several extinction and recolonization events, but little is known about present gene flow between populations of the east and west. We used 12 validated microsatellite markers to analyse 1580 hair and faecal samples collected during six consecutive years (2005–2010) in the Pasvik Valley at 70_N on the border of Norway, Finland and Russia. Our results showed an overall high correlation between the annual estimates of population size (Nc), density (D), effective size (Ne) and Ne ⁄Nc ratio. Furthermore, we observed a genetic heterogeneity of _0.8 and high Ne ⁄Nc ratios of _0.6, which suggests gene flow from the east. Thus, we expanded the population genetic study to include Karelia (Russia, Finland), Va¨sterbotten (Sweden) and Troms (Norway) (477 individuals in total) and detected four distinct genetic clusters with low migration rates among the regions. More specifically, we found that differentiation was relatively low from the Pasvik Valley towards the south and east, whereas, in contrast, moderately high pairwise FST values (0.91–0.12) were detected between the east and the west. Our results indicate ongoing limits to gene flow towards the west, and the existence of barriers to migration between eastern and western brown bear populations in Northern Europe.

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I 2011 ble det for tredje år på rad gjennomført en landsdekkende prøveinnsamling for brunbjørn i det nasjonale overvåkingsprogrammet for rovvilt. Denne rapporten omhandler DNA-analysen av 1208 prøver (877 ekskrementprøver, 316 hårprøver og 15 vevsprøver) fra brunbjørn (Ursus arctos) innsamla i Norge i 2011. DNA-profiler ble bestemt ved analyse av 8 ulike STR (short tandem repeats)-markører og en kjønnsmarkør. Alle positive prøver ble sammenlignet med Bioforsk Svanhovd sin genetiske database med individer fra perioden 2005 til 2010. Av de 1208 prøvene var 757 (63 %) prøver positive for brunbjørn, noe som utgjør en nedgang i andelen positive prøver i forhold til 2010 (68 %). Det ble totalt identifisert 151 individer av brunbjørn (51 hunnbjørn og 100 hannbjørn), der 111 (74 %) individer var tidligere påvist med DNA-prøve i Norge. Det påviste antallet bjørn (151) var altså lavere enn i 2010 (166), men kjønnsfordelingen (34 % hunnbjørn) var omtrent den samme (32 %). Det ble som tidligere påvist flest bjørn i fylkene Finnmark, Nord-Trøndelag, Troms og Hedmark. I Troms ble det samlet inn færre prøver enn tidligere, og dette kan forklare hvorfor antallet bjørn i dette fylket ble tilnærmet halvert i forhold til 2010. Det var en høy andel gjenfunn av individer fra tidligere år i de ulike fylkene (> 63 %), med unntak av Sør-Trøndelag der det var relativt få gjenfunn. Basert på antall hunnbjørn (n=51) påvist med DNA, ble antall ynglinger i Norge i 2011 estimert til 5,9. Tilleggsanalyser viste at mitokondrie-DNA fra andre arter kunne påvises i omtrent halvparten av de negative ekskrementprøvene. Dette tyder på det i 2011 også har blitt samlet inn prøver fra andre arter enn bjørn eller at det i noen tilfeller der ekskrementene inneholder kjøtt/bein viser resultatet at andre arter (elg) har vært føde for bjørn.

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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.

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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.

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Rapporten beskriver DNA-analysen av 1224 prøver (899 ekskrementprøver, 314 hårprøver og 10 vevsprøver og 1 blodprøve) fra brunbjørn (Ursus arctos) samla inn i Norge i 2010 gjennom det nasjonale overvåkningsprogrammet for rovvilt. Året 2010 er det andre året på rad hvor en landsdekkende innsamling blir gjennomført. Prøvene ble DNA-analysert med 8 ulike STR-markører og en kjønnsspesifikk test. Av de 1224 prøvene var 831 (68 %) prøver positive for brunbjørn, noe som er en økning i forhold til 2009 (63 %). Fra disse prøvene ble det identifisert 166 individer av brunbjørn (53 hunnbjørn og 113 hannbjørn), der 106 individer (64 %) var tidligere påvist i Norge. Resultatene våre viser at antallet bjørn (166) og kjønnsfordelingen (32 % hunner) er omtrent det samme som 2009 (164 individer og 30 % hunner). Det ble som tidligere påvist flest bjørn i fylkene Hedmark, Nord-Trøndelag, Troms og Finnmark. Prosentandelen gjenfunn varierte i de ulike fylkene og i forhold til 2009, med en høy andel gjenfunn i Nord-Trøndelag og Troms (ca. 70 %), mens Finnmark hadde en relativt lav andel gjenfunn i 2010 (53 %). Nytt av året 2010 er at det også er påvist en hunnbjørn i hvert av fylkene Nordland og Sør-Trøndelag, og at det ble påvist en hannbjørn i hvert av fylkene Akershus og Sogn og Fjordane. Basert på antallet hunnbjørn (n=53) har vi også estimert antallet ynglinger i Norge i 2010 til å ha vært 6,2. I tillegg viste utvida DNA-analyser at mitokondrie- DNA fra en annen art kunne påvises i ca. halvparten av de brunbjørn-negative ekskrement prøvene. DNA, brunbjørn, Ursus arctos, STR, mtDNA, overvåking, Norge, DNA, brown bear, Ursus arctos, STR, mtDNA, monitoring, Norway

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Mitokondrielt DNA (mtDNA) forekommer i høyt kopitall i celler, og viser sekvenser med høy spesifisitet for ulike arter. Vi har utviklet en multiplex PCR-analyse for mtDNA for rødrev (Vulpes vulpes), elg (Alces alces), rein (Rangifer tarandus), grevling (Meles meles) og mårhund (Nyctereutes procyonoides). Multipleks mtDNA-assayet ble anvendt til analyse av 344 bjørne-negative ekskrementer fra innsamlingen til overvåkning av brunbjørn i Västerbotten i Sverige i 2009. Vi har tidligere rapportert påvisning av brunbjørn-DNA i 997 (74 %) av 1341 ekskrementprøver fra denne innsamlingen i felten i 2009. Multipleks mtDNA-testen viste at rødrev (7,4 %) og elg (4,4 %) var de hyppigst forekommende forvekslingsartene i denne feltinnsamlingen. I tillegg ble det påvist grevling, rein og mårhund i et mindre antall prøver. Blandinger av to eller tre arter ble påvist i 60 prøver (4,5 %), og årsaken til dette kan være påvisning av byttedyr-DNA i ekskrementene fra kjøttetere. I så fall er andelen rødrevekskrementer blant forvekslingene høyere (~10 %) enn det som ble påvist fra prøver med utvetydig artsidentitet alene (7,4 %). Samlet viser denne studien at arten kunne bestemmes for 1233 (997 brunbjørn og 236 annen art, totalt 92 %) av 1341 ekskrementer samlet inn i Västerbotten i 2009.

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The effect of zinc on soil nitrification and composition of the microbial community in soil was investigated using a full factorial experiment with five zinc concentrations and four levels of biological complexity (microbes only, microbes and earthworms (Eisenia fetida), microbes and Italian ryegrass (Lolium multiflorum var. Macho), and microbes, ryegrass and earthworms). After 6 weeks of exposure, the activity of soil nitrifying bacteria was measured and the microbial community structure was characterized by phospholipid fatty acid (PLFA) analysis. Soil nitrification and several PLFA markers were significantly influenced by either zinc addition and/or the presence of earthworms or ryegrass, and one of the most pronounced changes was the increase of fungi and decrease of bacteria with increasing concentrations of zinc. Of particular interest, however, was the potential interaction between the presence of plants and/or earthworms and the effect of zinc, which the factorial study design allowed us to explore. Such an effect was observed in two cases: Earthworms reduced the positive effect of zinc on the fungal biomass (ANOVA, p = 0.03), and the effect of earthworms on the soil nitrification activity depended on zinc concentration (ANOVA, p < 0.05). The effect of earthworm presence was not very large, but it does show that multispecies tests might give information about metal toxicity, or bioavailability that cannot be predicted from single-species tests. (c) 2006 Elsevier Ltd. All rights reserved.