Top-down control of a marine mesopredator: Increase in native white-tailed eagles accelerates the extinction of an endangered seabird population

1. Bottom-up control is an important regulator of marine mesopredators such as seabirds. The prevalence of top-down control on these species is however less well understood. In particular, how native predators affect seabird populations has rarely been quantified. 2. Here, we investigate how an increase in white-tailed eagles in northern Norway, a stronghold for the species, affected a local population of 25,000 pairs of black-legged kittiwakes, a red-listed seabird, during a 42-year period ending with colony extinction. We use a natural experiment of two neighbouring colonies with/without eagle predation to disentangle the effects of eagles from local kittiwake foraging conditions (using size of young herring as a proxy). 3. At the colony where eagle predation occurred, and in contrast to the eagle-free colony, kittiwake breeding success and population size declined with increased eagle abundance , the latter more strongly under poor foraging conditions. Breeding success increased with foraging conditions at both colonies. 4. Simple population modelling shows that although conditions were insufficient to sustain the eagle-exposed colony, the increased abundance of eagles sped up its extirpation by many years. 5. Policy implications. Our study shows that top-down effects from avian predators can be significant regulators of seabird populations, challenging their conservation where native, often protected, predators are rising. Such effects, and their possible interaction with other factors, must also be accounted for when using seabird demographic traits as environmental indicators and when developing more flexible and effective management and action plans.Top-down control of a marine mesopredator: Increase in native white-tailed eagles accelerates the extinction of an endangered seabird populationpublishedVersio

Snowy Owl (Bubo scandiacus) males select the highest vantage points around nests.

In July 2007 we collected a total of 309 Snowy Owl (Bubo scandiacus) pellets from 35 vantage points in an area where we located four Snowy Owl territories in northern Norway. The number of pellets found at each vantage point ranged from 1 to 39 (mean: 8.8, median: 6, SD + 1.8). While the four nests were situated 513, 522, 524 and 529 m asl respectively (mean 522 m, SD + 4.1), the vantage points with pellets were situated from 515 to 590 m asl (mean: 550.2 m, median: 548 m, SD + 16.3). We found the highest number of pellets at the highest vantage points. The increase of pellets with higher elevation above the nest site indicates that Snowy Owls spent more time on the highest vantage points in the territory. Although some pellets may have been cast by the females before they started incubating, the majority of pellets were most likely cast by males. We hypothesise that the presence of elevated mounds, rocks or heights around the nest site of Snowy Owls may be an important feature for the Snowy Owls when selecting the breeding territory, increasing the male´s ability to scrutinize his territory for both prey and possible threats to the nest and himself.publishedVersio

Development and optimization of animal origin-free, serum-free media for human treg manufacturing

Regulatory T cells (Treg) constitute a small subset of immunosuppressive CD4+ T cells. Studies have shown that imbalanced or aberrant Treg function can result in autoimmune disorders. The importance of Tregs in dampening immune responses has been described in multiple studies and Treg immunotherapies are being explored to develop personalized therapies for various autoimmune diseases. Scalable commercial development of Treg therapies suffers similar challenges as other T cell immunotherapies: biosafety and supply chain concerns of human serum and limitations regarding bioprocess development due to serum variability. Additionally, there a challenges regarding Treg isolation for both magnetically isolated (blockade of CD25+ epitope may affect function and low purity) and flow cytometry sorted Tregs (low numbers and viability). In addition, the starting population and purity (measured by FOXP3 expression) can be low, resulting in small cell numbers post expansion which can impact dose escalation studies. To address these challenges, we are developing a serum-free, animal origin component – free, defined medium and Treg optimized Dynabeads™. Our strategy was to exploit metabolic differences between Tregs and conventional Tcells as well as optimizing the level of activation ligands to develop a defined Treg manufacturing system. Using design of experiment (DOE) approaches we explored factors described in the literature to be associated with Treg development. DOE studies were followed by testing in combination with Treg Dynabeads™ in development. Feasibility was evaluated with positively selected Tregs (CD4+CD25+CD127lo, n=5). Tregs cultured in our system achieve higher FOXP3+ frequencies (\u3e60% FOXP3+) outperforming control containing 10% human serum (~30% FOXP3+). In summary, our results suggest that serum can be eliminated from Treg workflows to generate highly suppressive enriched FOXP3+ Treg immunotherapy product. We believe that our defined serum-free medium and Dynabeads™ Treg system will enable the development of better immunotherapies for autoimmunity

Home range and excursive post-breeding movements of Eurasian Eagle-owls revealed by GPS satellite transmitters

Investigating space use of wild birds provides important knowledge of bird behavior and ecology, which is crucial in the management and conservation of threatened species. In the present study, we used GPS satellite telemetry to investigate space use and movements of seven adult Eurasian Eagle-Owls (Bubo bubo) in Norway during breeding and post-breeding seasons. Breeding adults had a mean home range size of 42.9 km2 (SD ± 35.1 km2; 95% kernel density estimation Had hoc), and five individuals performed long (>20 km) excursive movements away from their breeding territories during autumn. Such wide-ranging behavior has not previously been reported for adults of the nominate subspecies B. b. bubo. The study demonstrates the need to investigate seasonal movements of species, populations, and age groups even if they are considered residents, and provides valuable information for management and conservation of the Eurasian Eagle-Owl.publishedVersionPaid open acces

Winter distribution of Steller's Eiders in the Varangerfjord, northern Norway

Arctic warming and decreasing sea-ice cover along the Siberian coast in the Arctic Ocean leads to greater accessibility for operations such as oil drilling and traffic of tankers. This implies increasing risks for Steller’s Eider Polysticta stelleri wintering, moulting and staging along the coasts of the Varanger Peninsula, Norway. Steller’s Eiders were surveyed by monthly counts during winter and early spring 2016/2017 to investigate numbers and distribution throughout the winter. The highest number of wintering Steller’s Eiders was found in January, representing ~7 % of the European population. In February–April numbers were lower, but at a rather stable level. We found relatively little variation in distribution between months, although the birds were more evenly distributed along the coast later in winter. Mean flock size was significantly larger in January than in March and April. Feeding behaviour was exclusively observed in shallow water, generally at depths of up to 6 m. Areas of focus for an oil pollution emergency plan are pointed out and discussed

Optimized process for regulatory T cell activation and expansion using Dynabeads™ Treg CD3/CD28 for clinical applications

CD4+CD25+ Tregs are a suppressive subset of CD4+ T helper cells important for the regulation of immune responses. Tregs are proven highly effective in preventing graft versus host disease (GVHD) and autoimmunity in murine models. The relative frequency of Tregs in peripheral blood is approximately 1-2% of total lymphocytes implicating the necessity of ex vivo expansion of Tregs prior to adoptive transfer for most clinical applications. The Dynabeads™ CD3⁄CD28 CTS™ has been developed for ex vivo isolation, activation, and expansion of human T cells for use in various immunotherapies. To address the specific needs for Treg expansion, we have generated a new product, Dynabeads™ Treg CD3/CD28, designed to provide optimal activation and expansion of Tregs. We have compared the functionality of Dynabeads™TregCD3/CD28 with other existing technologies (competitors and Dynabeads™ CD3⁄CD28 CTS™) regarding expansion of CD4+CD25+CD127low flow sorted Tregs and magnetically isolated Tregs. Our studies demonstrate superior fold expansion of functional Tregs with the Dynabeads™ Treg CD3/CD28. We show several hundred fold expansion of Treg cells in 14 days culture and with maintenance of high FOXP3 expression and suppressive activity. This optimized Dynabeads™ Treg CD3/CD28 support consistent and scalable Treg manufacturing for immunotherapies, supplementing our Cell Therapy System (CTSTM) portfolio. For Research Use Only. Not for use in diagnostic procedures

Movements of Tundra Bean Goose Anser fabalis rossicus neck-banded in northern Scandinavia

Based on 1420 neck-band reports we could map the movements of Tundra Bean Geese marked in northern Scandinavia. With few exceptions, the maps show a distinct migration pattern through Sweden to the main wintering area in NE Scania. In mild winters, only a few individuals extend their migration into continental Europe, but during severe winters, a large proportion of the sightings are from Germany and Denmark.Based on 1420 neck-band reports we could map the movements of Tundra Bean Geese marked in northern Scandinavia. With few exceptions, the maps show a distinct migration pattern through Sweden to the main wintering area in NE Scania. In mild winters, only a few individuals extend their migration into continental Europe, but during severe winters, a large proportion of the sightings are from Germany and Denmark

Snowy Owl nest failures caused by blackfly attacks on incubating females

Blackflies (Simuliidae) have been shown to influence birds negatively in several ways. In 2011, during a peak lemming year, we found that two of 28 nests of Snowy Owls Bubo scandiacus in Northern Norway and Finland failed due to blackfly attacks on the incubating female. The observations also suggest that adult survival may be influenced by these insects. The owls’ choice of breeding habitat can be decisive in their vulnerability to blackflies.Blackflies (Simuliidae) have been shown to influence birds negatively in several ways. In 2011, during a peak lemming year, we found that two of 28 nests of Snowy Owls Bubo scandiacus in Northern Norway and Finland failed due to blackfly attacks on the incubating female. The observations also suggest that adult survival may be influenced by these insects. The owls' choice of breeding habitat can be decisive in their vulnerability to blackflies

Interleukin-17–producing T cells are enriched in the joints of children with arthritis, but have a reciprocal relationship to regulatory T cell numbers

Objective. To identify interleukin-17 (IL-17)producing T cells from patients with juvenile idiopathic arthritis (JIA), and investigate their cytokine production, migratory capacity, and relationship to Treg cells at sites of inflammation, as well as to test the hypothesis that IL-17+ T cell numbers correlate with clinical phenotype in childhood arthritis.Methods. Flow cytometry was used to analyze the phenotype, cytokine production, and chemokine receptor expression of IL-17-producing T cells in peripheral blood and synovial fluid mononuclear cells from 36 children with JIA, in parallel with analysis of forkhead box P3 (FoxP3)-positive Treg cells. Migration of IL-17+ T cells toward CCL20 was assessed by a Transwell assay. Synovial tissue was analyzed by immunohistochemistry for IL-17 and IL-22.Results. IL-17+ T cells were enriched in the joints of children with RA as compared with the blood of RA patients (P = 0.0001) and controls (P = 0.018) and were demonstrated in synovial tissue. IL-17+ T cell numbers were higher in patients with extended oligoarthritis, the more severe subtype of JIA, as compared with patients with persistent oligoarthritis, the milder subtype (P = 0.046). Within the joint, there was an inverse relationship between IL-17+ T cells and FoxP3+ Treg cells (r = 0.61, P = 0.016). IL-17+,CD4+ T cells were uniformly CCR6+ and migrated toward CCL20, but synovial IL-17+ T cells had variable CCR4 expression. A proportion of IL-17+ synovial T cells produced IL-22 and interferon-gamma.Conclusion. This study is the first to define the frequency and characteristics of "Th17" cells in JIA. We suggest that these highly proinflammatory cells contribute to joint pathology, as indicated by relationships with clinical phenotypes, and that the balance between IL-17+ T cells and Treg cells may be critical to outcome

Life-cycle analysis of an endangered migratory goose to assess the impact ofconservation actions on population recovery

Evaluating the effectiveness of conservation actions is challenging for migratory species because a population can be impacted anywhere along its route. Conservation actions for the critically endangered Fennoscandian lesser white-fronted goose population include culling of red foxes in the breeding area and habitat improvements and reduction of illegal hunting in the non-breeding areas. One goal of the predator control strategy is to prevent adult birds from using an autumn migration route through western Asia, where mortality is believed to be higher than on the migration route through eastern Europe. We used 23 years of count data obtained at different staging areas to parameterize a seasonal state-space model describing the full-annual cycle dynamics of this population and evaluate whether the recent population recovery was linked to these conservation efforts. The results did not provide evidence that predator control influenced population recovery, as survival on the European route did not appear higher than on the allegedly riskier Asian route. However, adult survival at staging areas on both routes and at wintering sites may have improved in the last decade, suggesting a positive effect of the other conser- vation initiatives. These results emphasize the importance of including the non-breeding dynamics in population assessments of migratory species and highlight the challenge of evaluating the efficacy of separate conservation actions when a proper experimental design is unfeasible. Our study, which is a unique case of cross-national, coordinated conservation efforts, exemplifies how to model complex population dynamics to assess the influ- ence of costly conservation initiatives. Goose management State-space model Management evaluation Lesser whitefronted goose Unmarked individuals Non-breeding dynamic