Trond Vidar Johnsen

Norwegian Institute for Nature Research, Nidaros, Sør-Trøndelag, Norway

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Publications (20)22.11 Total impact

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    ABSTRACT: Jacobsen, K.-O., Stien, A., Nygård, T., Kleven, O., Mabille, G., Johnsen, T.V., Opgård, O., Østlyngen, A., Johansen, K. & Myklevoll, V. 2014. The Golden Eagle in Finnmark. Annual Report 2013 – NINA Report 1023. 26 pp. The main objectives of this study were to gain more knowledge of the population of Golden Eagles in Finnmark. We have conducted studies of behavior, diet, reproduction and migration during 2001-2013, and our knowledge has improved substantially. The breeding population is now estimated to 140-160 pairs. Overall, 72% of the territories were on average occupied per year during the surveyed years. The breeding success of Golden Eagles is higher in the inland territories (0.51 young/territory) compared to territories found in the fjords and valleys and on the coastal islands (0.29-0.30 young/territory). There was minor variation in breeding success up to 2008. 2009 was a very poor year, but the breeding success improved again in 2010 and 2011 before we got a very poor year again in 2012. There was an increase in production of young in 2013. However, since only a moderate number of pairs made breeding attempts, the total production did not become very high. These between year variations were observed throughout the study area, from the costal islands to inland Finnmark. This implies high levels of breeding success synchrony on large spatial scales in Finnmark. This variation does not seem to be caused by climatic variation. More likely it is associated with variation in the population sizes of key prey species, in particular grouse/ptarmigan and small rodents. The project has for the moment no eagles with active satellite transmitters. GIS-analyses show that the young Golden Eagles do not use calving areas for semi-domestic reindeer in May, but start to use them from June. We have done DNA-analyses of some of the feathers collected in the period 2001-2013. This have given a very high success (94%) in creating DNA-profiles of breeding adults
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    ABSTRACT: Parasites are natural stressors that may have multiple negative effects on their host as they usurp energy and nutrients and may lead to costly immune responses that may lead to oxidative stress. The objective of this study was to explore effects of parasites by treating chicks of two raptor species against both internal and external parasites. Treatment against ectoparasites led to a reduction in circulating immunoglobulin plasma levels in male chicks. Treatment against endoparasites reduced immunoglobulin plasma levels in white-tailed sea eagles. Furthermore, total oxidant status was higher when not receiving any parasite reduction treatment and when receiving both endo- and ectoparasitic reduction treatment compared with receiving only one antiparasite treatment.
    Ecology and Evolution 12/2013; 3(16):5157-5166. DOI:10.1002/ece3.891 · 2.32 Impact Factor
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    ABSTRACT: The extent to which persistent organic pollutants (POPs) with different physicochemical properties originated from the food (dietary input) was assessed in raptor nestlings. Lipophilic polychlorinated biphenyl (PCB) 153, 1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE) and hexachlorobenzene (HCB), and protein-bound perfluorooctane sulfonate (PFOS), were measured repeatedly in blood plasma of individual goshawk (Accipiter gentilis) and white-tailed eagle (Haliaeetus albicilla) nestlings; 1-3 weeks after hatching and near fledging. Maternally derived POPs dilute as nestlings grow (growth dilution), and increasing plasma concentrations would indicate dietary input. Firstly, plasma concentrations given no dietary input was estimated, and concentrations of p,p'-DDE, HCB, and notably PFOS were significantly higher than predicted from a growth dilution scenario (∼1.5-2.5 fold higher; P < 0.001). In contrast, PCB 153 declined in both species, although concentrations were 1.16 fold higher than predicted in white-tailed eagle nestlings (P < 0.03). Secondly, the relationships between plasma POP concentrations and trophic position (δ(15) N) and dietary carbon source (δ(13) C) were analysed in body feathers, controlling for growth rate. Both δ(15) N and δ(13) C were significantly associated to the accumulation of most POPs, except PFOS. In conclusion, pollutant data acquired in plasma of nestling raptors should be interpreted and further investigated in the light of individual feeding ecology, and the use of raptor nestlings as sentinels for POP monitoring could be optimized by correcting for different factors, for example body condition, brood size and age. Environ Toxicol Chem © 2013 SETAC.
    Environmental Toxicology and Chemistry 08/2013; 32(11):2520-2527. DOI:10.1002/etc.2329 · 2.83 Impact Factor
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    ABSTRACT: Top predators in northern ecosystems may suffer from exposure to persistent organic pollutants (POPs) as this exposure may synergistically interact with already elevated natural stress in these ecosystems. In the present study, we aimed at identifying biological (sex, body condition), ecological (dietary carbon source, trophic level) and spatial factors (local habitat, regional nest location) that may influence intra- and interspecific variation in exposure of subarctic predatory bird nestlings to polychlorinated biphenyl 153 (CB 153), polybrominated diphenyl ether 47 (BDE 47), dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlorobenzene (HCB). During three breeding seasons (2008-2010), we sampled body feathers from fully-grown nestlings of three ecologically distinct predatory bird species in subarctic Norway: Northern Goshawk (Accipiter gentilis), White-tailed Eagle (Haliaeetus albicilla) and Golden Eagle (Aquila chrysaetos). The present study analysed, for the first time, body feathers for both POPs and carbon (δ(13)C) and nitrogen (δ(15)N) stable isotopes, thus integrating the dietary carbon source, trophic level and POP exposure for the larger part of the nestling stage. Intraspecific variation in exposure was driven by a combination of ecological and spatial factors, often different for individual compounds. In addition, combinations for individual compounds differed among species. Trophic level and local habitat were the predominant predictors for CB 153, p,p'-DDE and BDE 47, indicating their biomagnification and decreasing levels according to coast>fjord>inland. Variation in exposure may also have been driven by inter-annual variation arisen from primary sources (e.g. p,p'-DDE) and/or possible revolatilisation from secondary sources (e.g. HCB). Interspecific differences in POP exposure were best explained by a combination of trophic level (biomagnification), dietary carbon source (food chain discrimination) and regional nest location (historical POP contamination). In conclusion, the combined analysis of POPs and stable isotopes in body feathers from fully-grown nestlings has identified ecological and spatial factors that may drive POP exposure over the larger part of the nestling stage. This methodological approach further promotes the promising use of nestling predatory bird body feathers as a non-destructive sampling strategy to integrate various toxicological and ecological proxies.
    Environment international 04/2013; 57-58C:25-33. DOI:10.1016/j.envint.2013.03.009 · 5.66 Impact Factor
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    ABSTRACT: Jacobsen, K.-O., Stien, A., Nygård, T. & Kleven, O., Johnsen, T.V., Opgård, O., Johansen, K., Østlyngen, A. & Myklevoll, V. 2013. The Golden Eagle in Finnmark. Annual Report 2012 – NINA Report 936. 22 pp. The main objectives of this study were to gain more knowledge of the population of Golden Eagles in Finnmark. We have conducted studies of behavior, diet, reproduction and migration during 2001-2012, and our knowledge has improved substantially. The breeding population is now estimated to 140-160 pairs. Overall, 73% of the territories were on average occupied per year during the surveyed years. The breeding success of Golden Eagles is higher in the inland territories (0,51 young/territory) compared to territories found in the fjords and valleys and on the coastal islands (0,30-0,31 young/territory). There was minor variation in breeding success up to 2008. 2009 was a very poor year, but the breeding success improved again in 2010 and 2011 before we got a very poor year again in 2012. These between year variations were observed throughout the study area, from the costal islands to inland Finnmark. This implies high levels of breeding success synchrony on large spatial scales in Finnmark. This variation does not seem to be caused by climatic variation. More likely it is associated with variation in the population sizes of key prey species, in particular grouse/ptarmigan and small rodents. The project has for the moment no eagles with active satellite transmitters. From 2012 we have started DNA-analysis of blood- and feathers samples.
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    ABSTRACT: Jacobsen, K.-O., Stien, A., Nygård, T. & Kleven, O., Johnsen, T.V., Opgård, O., Johansen, K., Østlyngen, A. & Myklevoll, V. 2013. The Golden Eagle in Finnmark. Annual Report 2012 – NINA Report 936. 22 pp. The main objectives of this study were to gain more knowledge of the population of Golden Eagles in Finnmark. We have conducted studies of behavior, diet, reproduction and migration during 2001-2012, and our knowledge has improved substantially. The breeding population is now estimated to 140-160 pairs. Overall, 73% of the territories were on average occupied per year during the surveyed years. The breeding success of Golden Eagles is higher in the inland territories (0,51 young/territory) compared to territories found in the fjords and valleys and on the coastal islands (0,30-0,31 young/territory). There was minor variation in breeding success up to 2008. 2009 was a very poor year, but the breeding success improved again in 2010 and 2011 before we got a very poor year again in 2012. These between year variations were observed throughout the study area, from the costal islands to inland Finnmark. This implies high levels of breeding success synchrony on large spatial scales in Finnmark. This variation does not seem to be caused by climatic variation. More likely it is associated with variation in the population sizes of key prey species, in particular grouse/ptarmigan and small rodents. The project has for the moment no eagles with active satellite transmitters. From 2012 we have started DNA-analysis of blood- and feathers samples.
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    ABSTRACT: Raptors are exposed to biomagnifying and toxic organohalogenated compounds (OHCs) such as organochlorines, brominated flame retardants and perfluorinated compounds. To investigate how OHC exposure may affect biochemical pathways we collected blood plasma from Norwegian northern goshawk (n=56), golden eagle (n=12) and white-tailed eagle (n=36) nestlings during three consecutive breeding seasons. We found that blood plasma concentrations of calcium, sodium, creatinine, cholesterol, albumin, total protein, urea, inorganic phosphate, protein:creatinine, urea:creatinine and uric acid:creatinine ratios and liver enzymes ALKP and ALAT were positively correlated to PCBs, chlordanes, p,p'-DDE, HCB, PFCs and/or PBDEs. Total bilirubin and glucose were negatively correlated to PCBs while magnesium and potassium were negatively correlated to HCB and p,p'-DDE. In addition, protein:creatinine and ALAT were also negatively correlated to PCBs and PFCs, respectively. The most significant relationships were found for the highly contaminated northern goshawks and white-tailed eagles. The statistical relationships between OHCs and BCCPs indicate that biochemical pathways could be influenced while it is uncertain if such changes have any health effects. The OHC concentrations were below concentrations causing reproductive toxicity in adults of other raptor species but similar to those of concern for endocrine disruption of thyroid hormones in e.g., bald eagles.
    Ecotoxicology and Environmental Safety 03/2012; 80:76-83. DOI:10.1016/j.ecoenv.2012.02.012 · 2.48 Impact Factor
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    ABSTRACT: In previous studies, feathers of adult predatory birds have been evaluated as valid non-destructive biomonitor matrices for persistent organic pollutants (POPs). In this study, we assessed for the first time the usefulness of nestling raptor feathers for non-destructive biomonitoring of POPs. For this purpose, we collected body feathers and blood of nestlings from three avian top predators from northern Norway: northern goshawks (Accipiter gentilis), white-tailed eagles (Haliaeetus albicilla) and golden eagles (Aquila chrysaetos). We were able to detect a broad spectrum of legacy POPs in the nestling feathers of all three species (Σ PCBs: 6.78-140ng g(-1); DDE: 3.15-145ng g(-1); Σ PBDEs: 0.538-7.56ng g(-1)). However, these concentrations were lower compared to other studies on raptor species, probably due to the aspect of monitoring of nestlings instead of adults. Besides their analytical suitability, nestling feathers also appear to be biologically informative: concentrations of most POPs in nestling feathers showed strong and significant correlations with blood plasma concentrations in all species (p<0.050; 0.775<r<0.994). In addition, the reported correlations between feathers and blood plasma were much higher than those previously reported for adult individuals. Accumulation profiles and species-specific differences were in accordance with other toxicological studies on avian species and generally in agreement with the specific ecology of the studied species. In summary, our results indicate that the use of nestling feathers of northern raptors may be a valid and promising non-destructive biomonitoring strategy for POPs in their ecosystems.
    Environment international 04/2011; 37(3):622-630. DOI:10.1016/j.envint.2010.12.007 · 5.66 Impact Factor
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    ABSTRACT: Organohalogen contaminants (OHCs) may affect various physiological parameters in birds including blood chemistry. We therefore examined blood plasma clinical-chemical parameters and OHCs in golden eagle, white-tailed eagle and goshawk chicks from Northern Norway. Correlation analyses on pooled data showed that alkaline phosphatase (ALKP), glucose and creatinine were significantly negatively correlated to various OHCs (all: p<0.05; r: -0.43 to -0.55; n=23), while alanine aminotransferase (ALAT), total protein, cholesterol, uric acid, total bilirubin, ratios protein:creatinine and uric acid:creatinine were significantly positively correlated to various OHCs (all: p<0.05; r: 0.43-0.96). Based on these relationships, we suggest that the OHC concentrations found in certain raptor chicks of Northern Scandinavia may impact blood plasma biochemistry in a way that indicates impacts on liver, kidney, bone, endocrinology and metabolism. In order to elaborate further on these relationships and mechanisms, we recommend that a larger study should take place in the near future.
    Ecotoxicology and Environmental Safety 10/2009; 73(1):7-17. DOI:10.1016/j.ecoenv.2009.08.017 · 2.48 Impact Factor
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    ABSTRACT: To assess the importance of semi-domesticated reindeer Rangifer tarandus calves in the diet of Golden Eagles Aquila chrysaetos, in Finnmark (northern Norway), we collected prey remains at 37 nests over six years (2001-2006). The study area was divided into 1) a fjord area, which is an important calving area for reindeer, and 2) an inland area where few reindeer give birth. 469 prey items were collected over the years. The diet of eagles was numerically dominated by birds (73% of collected prey items), especially willow/rock ptarmigan Lagopus spp. (51%), while mammals made up 27%, with mountain hare Lepus timidus as the most common species. Remains of reindeer calves were found in half of the nests studied and made up 8.5% of the collected prey items: 13.2% in the fjord area and 6.5% in the inland area. There was a higher chance of finding reindeer calves at nests in the fjord area than inland, and in nests situated in birch forest than in pine forest. The number of reindeer calves in the Golden Eagle diet in Finnmark corroborates well other studies from northern Fermoscandia. The importance of the Golden Eagle as a predator on reindeer can't, however, be assessed here.
    Ornis Fennica 01/2007; 84(3):112-118. · 0.67 Impact Factor
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    Sveinn Are · Hanssen Kjell · Einar Erikstad · Trond Vidar Johnsen
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    Karl-Otto Jacobsen · Sten-Richard Birkely · Trond Vidar Johnsen
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    Karl-Birger Strann · Vigdis Frivoll · Trond V Johnsen
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    Karl-Otto Jacobsen · Trond Vidar Johnsen · Ingunn Tombre
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    Karl-Birger Strann · Vigdis Frivoll · Trond V Johnsen
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