Ida Marie Bardalen Fløystad

Senior Engineer

(+47) 476 47 103
ida.floystad@nibio.no

Place
Svanhovd

Visiting address
Svanhovd, NO-9925 Svanvik

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Abstract

Since 2005, the population of the trans-border brown bear (Ursus arctos) in Trilateral Park Pasvik-Inari (Norway-Finland-Russia) has been monitored by using genetic analyses of hair and faeces collected randomly in the field. A more systematic method using hair traps every fourth year was initiated in 2007 to collect brown bear hairs for genetic analysis. The method consisted of 56 hair traps in Norway, Finland and Russia in a 5 x 5 km2 grid cell system (ca 1400 km2). The project was repeated in 2011, 2015, 2019 and now in 2023. This season’s sampling was carried out in Pasvik (Norway) - Inari (Finland) area (43 squares, 1075 km2), using the same methodology as in the previous studies. A total of 97 samples were collected, where 45 samples came from Finland and 52 samples from Norway. In the bear specific analysis, 71 (73 %) of the 97 hair samples were positive. A complete DNA profile could be determined for 63 of the positive samples. In total, 22 different bear individuals were detected (10 females and 12 males). Of these 22 bears, 12 bears were detected in previous years, while 10 were previously unknown bears. In total, 13 bears were detected in Finland and 11 bears in Norway. This year’s sampling has the 2nd highest success rate in number of individuals detected per grid square, with 0,51 individual per grid square compared to 0,81 individuals in 2019 (highest success rate), 0,49 in 2015, 0,35 in 2011 and 0,42 in 2009. Our results showed that even with a smaller study area, the hair trap project every 4th year provides valuable information on the brown bear individuals in addition to a random sampling in the field (The National Monitoring Program for brown bears in Norway).

Abstract

Gjennom det nasjonale overvåkingsprogrammet for rovvilt i Norge ble det i 2020 samlet inn prøver til DNA-analyse med antatt opphav fra brunbjørn (Ursus arctos) for tolvte år på rad. Av 1361 innsamlede prøver i 2020, ble 1351 inkludert i den genetiske analysen (850 ekskrementprøver, 489 hårprøver, 10 vevsprøver og 2 urinprøver) og 67 % var positive for brunbjørn. Totalt gav 708 prøver (52 %) en godkjent DNA-profil, og det ble fra disse prøvene påvist 150 ulike brunbjørner; 65 hunnbjørner og 85 hannbjørner. Dette var en økning på 1,4 % (2 individer) sammenlignet med 2019. Dette er det høyeste antallet brunbjørn registrert siden 2011. Forekomsten av brunbjørn var, som i foregående år, hovedsakelig konsentrert i fylkene Troms og Finnmark (66), Innlandet (52) og Trøndelag (29). Av det totale antallet brunbjørner påvist i 2020 var 70 % (105 individer) tidligere påvist i Norge, noe som utgjør en økning i gjenfunn med 4 prosentpoeng i forhold til i fjor. Om man inkluderer gjenfunn fra Sverige, Finland og Russland utgjør det totale antallet gjenfunn 112 individer (75 %). Basert på prøver fra påviste hunnbjørner ble det estimert 8,5 ynglinger i Norge i 2020. Dette er det høyeste estimatet på antall ynglinger siden overvå-kingen startet i 2009. De estimerte ynglingene i 2020 fordeler seg med 3,1 i rovviltregion 5 (Inn-landet), 2,9 i region 6 (Trøndelag) og 2,5 i region 8 (Troms og Finnmark).

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Abstract

Knowledge about the connectivity among natural populations is essential to identify management units for effective conservation actions. Conservation-minded management has led to the recovery of large carnivore populations in northern Europe, possibly restoring connectivity between the two separated, but expanding brown bear (Ursus arctos) populations on the Scandinavian peninsula to the west and Karelia, a part of the large Eurasian population, to the east. The degree of connectivity between these populations has been poorly understood, therefore we investigated the extent of connectivity between the two populations using autosomal microsatellites and Y chromosome haplotypes in 924 male bears (the dispersing sex), sampled during a period of 12 years (2005–2017) across the transborder area where these two populations meet. Our results showed that the two populations are not genetically isolated as reported in earlier studies. We detected recent asymmetrical gene flow at a rate (individuals per generation) of 4.6–5.5 (1%) from Karelia into Scandinavia, whereas the rate was approximately 27.1–34.5 (8%) in the opposite direction. We estimated historical gene flow of effective number of migrants to be between 1.7 and 2.5 between the populations. Analyses of Y chromosome markers supported these results. Successful recovery and expansion of both populations led to the restoration of connectivity, however, it is asymmetric, possibly due to different recovery histories and population densities. By aligning monitoring between neighboring countries, we were able to better understand the biological processes across the relevant spatial scale. Brown bear Genetic structure Male gene flow Microsatellites Migration Recovery Ursus arctos Wildlife monitoring Y chromosome

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Abstract

Loss of Arctic sea ice owing to climate change is predicted to reduce both genetic diversity and gene flow in ice-dependent species, with potentially negative consequences for their long-term viability. Here, we tested for the population-genetic impacts of reduced sea ice cover on the polar bear (Ursus maritimus) sampled across two decades (1995–2016) from the Svalbard Archipelago, Norway, an area that is affected by rapid sea ice loss in the Arctic Barents Sea. We analysed genetic variation at 22 microsatellite loci for 626 polar bears from four sampling areas within the archipelago. Our results revealed a 3–10% loss of genetic diversity across the study period, accompanied by a near 200% increase in genetic differentiation across regions. These effects may best be explained by a decrease in gene flow caused by habitat fragmentation owing to the loss of sea ice coverage, resulting in increased inbreeding of local polar bears within the focal sampling areas in the Svalbard Archipelago. This study illustrates the importance of genetic monitoring for developing adaptive management strategies for polar bears and other ice-dependent species.

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Abstract

Wildlife managers conduct population inventories to monitor species, particularly those at-risk. Although costly and time consuming, grid-based DNA hair-snag sampling has been the standard protocol for grizzly bear inventories in North America, while opportunistic fecal DNA sampling is more commonly used in Europe. Our aim is to determine if low-cost, low-effort scat sampling along roads can replace the current standard. We compare two genetic non-invasive techniques using concurrent sampling within the same grid system and spatially explicit capture–recapture. We found that given our methodology and the present status of fecal genotyping for grizzly bears, scat sampling along roads cannot replace hair sampling to estimate population size in low-density areas. Hair sampling identified the majority of individual grizzly bears, with a higher success rate of individuals identified from grizzly bear samples (100%) compared to scat sampling (14%). Using scat DNA to supplement hair data did not change population estimates, but it did improve estimate precision. Scat samples had higher success identifying species (98%) compared with hair (80%). Scat sampling detected grizzly bears in grid cells where hair sampling showed non-detection, with almost twice the number of cells indicating grizzly bear presence. Based on our methods and projected expenses for future implementation, we estimated an approximate 30% cost reduction for sampling scat relative to hair. Our research explores the application of genetic non-invasive approaches to monitor bear populations. We recommend wildlife managers continue to use hair-snag sampling as the primary method for DNA inventories, while employing scat sampling as supplemental to increase estimate precision. Scat sampling may better indicate presence of bear species through greater numbers and spatial distribution of detections, if sampling is systematic across the entire area of interest. Our findings speak to the management of other species and regions, and contribute to ongoing advances of monitoring wildlife populations.

Abstract

Knowledge about population genetic structure and dispersal capabilities is important for the development of targeted management strategies for agricultural pest species. The apple fruit moth, Argyresthia conjugella (Lepidoptera, Yponomeutidae), is a pre-dispersal seed predator. Larvae feed on rowanberries (Sorbus aucuparia), and when rowanberry seed production is low (i.e., inter-masting), the moth switches from laying eggs in rowanberries to apples (Malus domestica), resulting in devastating losses in apple crops. Using genetic methods, we investigated if this small moth expresses any local genetic structure, or alternatively if gene flow may be high within the Scandinavian Peninsula (~850.000 km2, 55o - 69o N). Genetic diversity was found to be high (n = 669, mean He = 0.71). For three out of ten tetranucleotide STRs, we detected heterozygote deficiency caused by null alleles, but tests showed little impact on the overall results. Genetic differentiation between the 28 sampling locations was very low (average FST = 0.016, P < 0.000). Surprisingly, we found that all individuals could be assigned to one of two non-geographic genetic clusters, and that a third, geographic cluster was found to be associated with 30% of the sampling locations, with weak but significant signals of isolation-by-distance. Conclusively, our findings suggest wind-aided dispersal and spatial synchrony of both sexes of the apple fruit moth over large areas and across very different climatic zones. We speculate that the species may recently have had two separate genetic origins caused by a genetic bottleneck after inter-masting, followed by rapid dispersal and homogenization of the gene pool across the landscape. We suggest further investigations of spatial genetic similarities and differences of the apple fruit moth at larger geographical scales, through life-stages, across inter-masting, and during attacks by the parasitoid wasp (Microgaster politus).

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Abstract

Siden 2005 har populasjonen av grenseoverskridene brunbjørn (Ursus arctos) i Trilateral Park Pasvik-Inari-Pechenga (Norge-Finland-Russland) blitt overvåket ved å bruke genetiske analyser av hår og ekskrement-prøver samlet inn opportunistisk i felt. En mer systematiske metode med hårfeller hvert fjerde år ble i 2007 startet opp for å samle inn bjørnehår til genetisk analyse. Metoden består i å sette ut 56 hårfeller med luktstoff i Norge, Finland og Russland i et 5 x 5 km2 rutenett (totalt ca. 1400 km2). Dette prosjektet ble gjentatt i 2011, 2015 og nå i sesongen 2019 med 58 ruter og ved bruk av samme metode som i 2007. I 2019 sesongen ble det samlet inn 182 prøver, der 66 av disse var fra Finland, 59 fra Norge og 57 fra Russland. For 144 (79,1 %) av de 182 hårprøvene var det positivt resultat i den bjørne-spesifikke analysen, og en komplett DNA profil kunne bestemmes for 136 av de positive prøvene. Det ble totalt påvist 47 forskjellige bjørner (25 hunner og 22 hanner). Av disse 47 individene var 24 påvist i tidligere år, mens 23 var til nå ukjente bjørner. Totalt ble det påvist 20 bjørner i Finland, 14 bjørner i Norge og 16 bjørner i Russland...

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Abstract

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

Abstract

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.

Abstract

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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Abstract

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