152 research outputs found
Home-range, movements and use of powerline poles of Eagle-Owls (Bubo bubo) at an island population in northern Norway
A dense island population of Eagle-Owls (Bubo bubo) close to the Arctic circle had suffered considerable mortality due to powerlines (electrocution and collision) throughout many decades. A study using GPS transmitter technology was carried out between 2009 and 2014. We studied home-range sizes, dispersal distances, mortality, and proposed mitigation techniques to prevent accidents. We found as expected that juvenile Eagle-Owls had larger home-ranges and moved farther than adults, but both age-groups moved much less than shown elsewhere in Europe. The probable reason for this was thought to be that this population was isolated by the surrounding sea, which might act as a barrier. The GPS data indicated that the poles of the grid were used as perching posts more than expected from a random distribution. This was explained by the lack of high trees and other elevated landscape features on these low islands. As a mitigation effort, we contributed to designing a perching-device for fitting on the poles that would prevent electrocution of the owls. This is now used by several grid-owners in coastal areas with high electrocution risk and is followed up by the National action plan for Eagle-Owl in Norway.publishedVersio
New insights from an eight-year study on per- and polyfluoroalkyl substances in an urban terrestrial ecosystem
Per- and polyfluoroalkyl substances (PFAS) were analysed in a high number of terrestrial samples of soil, earthworm, bird eggs and liver from red fox and brown rat in an urban area in Norway from 2013 to 2020. PFOS and the long chain PFCAs were the most dominating compounds in all samples, proving their ubiquitous distribution. Other less studied compounds such as 6:2 FTS were first and foremost detected in earthworm. 8:2 FTS was found in many samples of fieldfare egg, sparrowhawk egg and earthworm, where the eggs had highest concentrations. Highest concentrations for both 6:2 FTS and 8:2 FTS were detected at present and former industry areas. FOSA was detected in many samples of the species with highest concentrations in red fox liver and brown rat liver of 3.3 and 5.5 ng/g ww.
PFAS concentrations from the urban area were significantly higher than from background areas indicating that some of the species can be suitable as markers for PFAS emissions in an urban environment. Fieldfare eggs had surprisingly high concentrations of PFOS and PFCA concentrations from areas known to be or have been influenced by industry. Biota-soil-accumulation factor and magnification calculations indicate accumulation and magnification potential for several PFAS.
Earthworm and fieldfare egg had average concentrations above the Canadian and European thresholds in diet for avian wildlife and predators. For earthworms, 18 % of the samples exceeded the European threshold (33 ng/g ww) of PFOS in prey for predators, and for fieldfare eggs, 35 % of the samples were above the same threshold. None of the soil samples exceeded a proposed PNEC of PFOS for soil living organisms of 373 ng/g dw
Migratory patterns of Ospreys (Pandion haliaetus) from central Norway
Migratory behaviour is subject to intraspecific variation and may be determined by the age, sex and population origin of individuals. Here we equipped eight juvenile Ospreys (Pandion haliaetus) with GPS-based satellite-transmitters to investigate their migratory behaviour from a recently re-established breeding area in central Norway. Migration routes fanned out widely across Europe, and migratory behaviour differed between individuals. Five of the eight Ospreys completed their first southward migration to wintering areas in tropical Africa. They travelled a median distance of 7,482 km and spent from 21 to 92 days on their journeys. Median travel distance was 120% longer than a straight-line distance. Stopover sites were located just before or immediately after crossings of geographical barriers and the differences in the time spent on the migratory journeys was mainly a consequence of the number of stopover days. Only two individuals gave signals long enough to enable us to track their first northward migration in their third calendar year. By including repeated migratory journeys for these two individuals we tracked a total of 20 sea crossings lasting between 4 and 24 hours, and 14 trans-Saharan journeys. Four of the sea crossings included periods of nocturnal flight. The duration of the trans-Saharan journeys varied from 130 to 276 hours and the birds showed a strict diurnal rhythm, with movements only during daytime. Repeated migratory journeys showed that the Ospreys were faithful to wintering and stopover sites. Our results show that Ospreys from central Norway migrate on a broad front over Europe. However, the majority of the juvenile Ospreys followed flyways through central and eastern Europe and finally settled down in wintering areas in eastern parts of western tropical Africa.publishedVersio
Habitat Utilization in White-Tailed Eagles (Haliaeetus albicilla) and the Displacement Impact of the Smøla Wind-Power Plant
On average, 7.8 white-tailed eagles (Haliaeetus albicilla) collide with wind turbines annually at the operating wind-power plant on the island of Smøla off the coast of central Norway. To better understand the impact of this wind-power plant on white-tailed eagles, we investigated how habitat utilization affected displacement effects. We collected data on habitat utilization in non-territorial subadult white-tailed eagles using global positioning system satellite telemetry (2004â2009). From these data, we estimated utilization distributions using the Brownian bridge movement model and analyzed them using Resource Utilization Functions. Home ranges were circa 10â30% smaller for subadults hatched on skerries and islets farther from the wind-power plant, and tended to be circa 40% larger during spring. Shallow sea, skerries, and islets were utilized extensively, as was marsh, heathland, and forest on the main island of Smøla. We noted lower selectivity for arable land and higher levels of differentiation in utilization among individuals for forest and islets. Females also had a nearly 4 times higher between-individual variation, which was likely due to longranging excursions. The within- and between-individual variation among seasons showed an annual pattern, with increasing between-individual variation toward summer. Displacement (indicated by an overall 40% proportional reduction in utilization) was more pronounced in the birdsâ second and third calendar year compared with their first calendar year, and during autumnâwinter. Reduced displacement during spring coincides with the white-tailed eagle pre-breeding period with increased flight activity. This may, in part, explain increased collision risk during spring. Possible displacement effects in white-tailed eagles may be avoided by siting wind-power plants farther inland or offshore, avoidance, collision risk, displacement, habitat use, habitat utilization, Haliaeetus albicilla, Norway,wind turbinesacceptedVersio
CO<sub>2</sub> minimum miscibility pressure determination of pure hydrocarbons in different temperatures using slimtube simulations
As wind energy deployment increases and larger wind-power plants are considered, bird fatalities through collision with moving turbine rotor blades are expected to increase. However, few (cost-) effective deterrent or mitigation measures have so far been developed to reduce the risk of collision. Provision of âpassiveâ visual cues may enhance the visibility of the rotor blades enabling birds to take evasive action in due time. Laboratory experiments have indicated that painting one of three rotor blades black minimizes motion smear (Hodos 2003, Minimization of motion smear: Reducing avian collisions with wind turbines). We tested the hypothesis that painting would increase the visibility of the blades, and that this would reduce fatality rates in situ, at the Smøla wind-power plant in Norway, using a BeforeâAfterâControlâImpact approach employing fatality searches. The annual fatality rate was significantly reduced at the turbines with a painted blade by over 70%, relative to the neighboring control (i.e., unpainted) turbines. The treatment had the largest effect on reduction of raptor fatalities; no white-tailed eagle carcasses were recorded after painting. Applying contrast painting to the rotor blades significantly reduced the collision risk for a range of birds. Painting the rotor blades at operational turbines was, however, resource demanding given that they had to be painted while in-place. However, if implemented before construction, this cost will be minimized. It is recommended to repeat this experiment at other sites to ensure that the outcomes are generic at various setting
The influence of natural variation and organohalogenated contaminants on physiological parameters in white-tailed eagle (<i>Haliaeetus albicilla</i>) nestlings from Norway
Raptor Interactions with Wind Energy: Case Studies from Around the World
The global potential for wind power generation is vast, and the number of installations is
increasing rapidly. We review case studies from around the world of the effects on raptors of wind-energy
development. Collision mortality, displacement, and habitat loss have the potential to cause population-level effects, especially for species that are rare or endangered. The impact on raptors has much to do with their behavior, so careful siting of wind-energy developments to avoid areas suited to raptor breeding, foraging, or migration would reduce these effects. At established wind farms that already conflict with raptors, reduction of fatalities may be feasible by curtailment of turbines as raptors approach, and offset through mitigation of other human causes of mortality such as electrocution and poisoning, provided the relative effects can be quantified. Measurement of raptor mortality at wind farms is the subject of intense effort and study, especially where mitigation is required by law, with novel statistical approaches recently made available to improve the notoriously difficult-to-estimate mortality rates of rare and hard-to-detect species. Global standards for wind farm placement, monitoring, and effects mitigation would be a valuable contribution to raptor conservation worldwide.publishedVersio
Screening av nye PFAS-stoffer 2018
This screening project has focused on the occurrence of conventional andemerging PFASs in terrestrial and marine environments, including the Arctic. Conventional PFASs were found to be wide-spread in the environment and for the first time in Norway reported in wolf, a top predator from the terrestrial environment.Otters living in close proximity to human settlements and preying on the marine food chain,are heavily contaminated with PFASs. Areas where ski-testing activitiesare common are a potential âhotspotâ where PFASs can enter the food chain. The difference in PFAS-profile between the samples indicatesthat the diversity in samples are necessary to reveal the complete picture of PFASs in the environment
Legacy and emerging organohalogenated compounds in feathers of Eurasian eagle-owls (Bubo bubo) in Norway: Spatiotemporal variations and associations with dietary proxies (δ13C and δ15N)
The occurrence of organohalogenated compounds (OHCs) in wildlife has received considerable attention over the last decades. Among the matrices used for OHCs biomonitoring, feathers are particularly useful as they can be collected in a minimally or non-invasive manner. In this study, concentrations of various legacy OHCs âpolychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs)â, as well as emerging OHCs âper- and polyfluoroalkyl substances (PFAS) and organophosphate ester flame retardants (OPEs)â were determined in feathers of 72 Eurasian eagle-owls (Bubo bubo) from Norway, with the goal of studying spatiotemporal variation using a non-invasive approach. Molted feathers were collected at nest sites from northern, central and southern Norway across four summers (2013â2016). Additionally, two museum-archived feathers from 1979 to 1989 were included. Stable carbon (δ13C) and nitrogen isotopes (δ15N) were used as dietary proxies. In total, 11 PFAS (sum range 8.25â215.90 ng gâ 1), 15 PCBs (4.19â430.01 ng gâ 1), 6 OCPs (1.48â220.94 ng gâ 1), 5 PBDEs (0.21â5.32 ng gâ 1) and 3 OPEs (4.49â222.21 ng gâ 1) were quantified. While we observed large variation in the values of both stable isotopes, suggesting a diverse diet of the eagle owls, only δ13C seemed to explain variation in PFAS concentrations. Geographic area and year were influential factors for δ15N and δ13C. Considerable spatial variation was observed in PFAS levels, with the southern area showing higher levels compared to northern and central Norway. For the rest of OHCs, we observed between-year variations; sum concentrations of PCBs, OCPs, PBDEs and OPEs reached a maximum in 2015 and 2016. Concentrations from 1979 to 1989 were within the ranges observed between 2013 and 2016. Overall, our data indicate high levels of legacy and emerging OHCs in a top predator in Norway, further highlighting the risk posed by OHCs to wildlife. Keywords: Bird of prey Feathers Isotopes OPE POP PFASpublishedVersio
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