Research database

Project information
Multiple stressors, Pollution, Raptor, Birds of prey, Ecology, Terrestrial
Project title
Effects of pollutants and other stress factors on northern raptors: RAPTOR
Project leader
Jan Ove Bustnes
Geographical localization of the research project in decimal degrees (max 5 per project, ex. 70,662°N and 23,707°E)
Tromsø 69°39′N 18°57′E; Trondheim: 63° 25’ N 010° 23’E


Participant: Nigel Yoccoz, UiT

Participant: Dorte Herzke, NILU 

Participant: Bård Jørgen Bårdsen, NINA 

Participant: Igor Eulaers, University of Århus 

Participant: Adrian Covaci, University of Antwerpen 

Participant: Sophie Bourgeon, UiT 

Participant: Christian Sonne, University of Århus 

Participant: Pilar Gomez Ramírez,  University of Murcia

Participant : Nikolaus Huber, Veterinärmedizinische Universität, Wien


Hazardous Substances
Funding Source



Summary of Results



  1. Large variation in telomere length among years has been documented in Baltic sea eagle chicks, suggesting variation in stress levels

  2. Sea eagle (Haliaeetus albicilla) feathers are suitable for monitoring of legacy persistent pollutants (PCB etc.), but not emerging contaminants (PFOS)


Bird species at the top of the food chain are vulnerable to bio-accumulating contaminants such as persistent organic pollutants (POPs) and toxic elements such as mercury.  Hence, birds of prey are valuable sentinels for research on the impacts of biomagnifying contaminants in nature. However, wildlife faces a multitude of natural and other anthropogenic stressors and this has been suggested to have far reaching impacts on the health of individuals and populations. Nevertheless, a major challenge is to document such effects in nature and be able to link natural and anthropogenic stress.


The RAPTOR project is a continuation of NFR and Flagship projects, which have received Flagship funding over several years including 2018. The project has also cooperated with the NFR project NewRaptor (2014-2016) led by Veerle Jaspers, NTNU.


In 2015, the RAPTOR project enabled us to write an application to NRF (the MARINFORSK Program) to study the ecological consequences of POPs in sea eagles: Ecological consequences of environmentally persistent pollutants in a marine sentinel species: A multi-stressor approach (EcoStress). EcoStress is a natural continuation of the sea eagle work in Tromsø, and expands the research internationally. This project was funded (2016-2018). In addition, the funding to the RAPTOR project by the Fram Centre, enabled us to write an application to NRF in 2016 (the Miljøforsk Program): Environmental stress processes: the role of anthropogenic pollution in a rapidly changing environment (EnviStress). This project was also funded (2017-2020) and is now being coordinated with the RAPTOR project.


In 2018, data collection on white-tailed eagles, as a part of a long-term monitoring of concentrations and effects, has continued. Blood samples and ecological data have been collected from 40 eagle chicks in Troms and Steigen. Effect parameters are measured over several years, such as oxidative stress, immunology and blood parameters. In 2018 a MSc student was accepted in the project studying impacts of POPs on the immune system of sea eaglets, using novel approaches (Leucocyte coping capacity: LCC) to examine new biomarkers of stress. This is in cooperation with University of Veterinary Medicine, Vienna.  The student (Elisabeth Hansen) has collected data over two field seasons and will complete her thesis in spring 2019.


In the EcoStress/RAPTOR projects, a MSc student (Tove Skotnes) has completed her thesis on telomeres from sea eagle chicks from the Baltic region (Skotnes 2018). The Baltic has been heavily polluted by POPs and serves a very good comparison for the Norwegian coast. Blood samples from the Baltic has been made available from 1995 to 2014. The analyses of telomeres were carried out by CNRS in Strasbourg and the POPs were analysed in University of Antwerp in 2018.


Data collection on tawny owls has continued in the Trøndelag region increasing the data series to 32 years. These data are the fundament in the EnviStress NFR application that will study stress process related to contaminants. The project has access to data on elements measurements in feathers from 1986-2005, and element analysis of feathers collected in the period 2006-2018 was completed in 2017 and 2018. This will allow us to test the hypothesis that heavy metal accumulation in terrestrial raptors is influenced by environmental conditions, as have been done in other works on POPs by our group. Furthermore, central issues raised by the EnviStress project are to assess the potential of pollution to modulate stress pathways, and thus capacity of such top predators to adapt to a rapidly changing environment. Stress is measured by CORT (a stress hormone) in feathers collected from tawny owls between 1986 and 2018. These feathers (~1180) have been cut and are now in the process of CORT analysis. In addition, a MSc student will start to measure isotopes in the same feathers in 2019 and do a thesis on the relationship between diet and toxic elements. 


Master and PhD-students involved in the project

Elisabeth Hansen, MSc UiT

Tove Skotnes, MSc UiT

For the Management

Pollution is a ubiquitous phenomenon of great interest for the society and the public. This project is a supplement for managers in different fields (nature and pollution); i.e. understanding the impact of pollution have on seabird populations. It could also potentially contribute to improve criteria for selecting POPs in the Stockholm Convention.


Published Results/Planned Publications



Løseth M.E. Briels, N.E., Flo, J., Malarvannan, G., Poma, G., Covaci, A., Herzke, D., Nygård, T., Bustnes, J.O., Jenssen, B.M. & Jaspers, V.L.B. 2019. White-tailed eagle (Haliaeetus albicilla) feathers are suitable for monitoring of legacy, but not emerging contaminants. Science of the Total Environment 647:527-533.


Bårdsen, B.J., Hanssen, S.A. & Bustnes, J.O. 2018. Multiple stressors in a sub-arctic marine bird: modelling the effect of pollution, climate change and predation on demography and population viability. Ecosphere 9: e02342




Løseth M.E., Briels, N.E., Flo, J., Eulaers, I., Nygård, T., Malarvannan, G., Poma, G., Covaci, A., Herzke, D., Bustnes, J.O., Jenssen, B.M. & Jaspers, V.L.B. Spatial and temporal variation of organohalogenated contaminants in nestlings: the role of age and diet. Environmental Pollution


Jouanneau, W., Bårdsen, B.-J., Herzke, D., Johnsen, T.V., Eulaers, I. & Bustnes, J.O. Spatial and temporal analysis of PFASs in White-tailed eagle (Haliaeetus albicilla) nestlings of Northern Norway a ten-year study.


Lee, M., Jaspers, V.L.B. Løseth M.E., Briels, N.E., Nygård, T., Bustnes, J.O., Waugh, C.A. Absence of Avian Influenza Antibodies in Raptor Nestlings from Norway.


Sun, J., Bustnes, J.O., Bårdsen, B.J., Dietz, R., Helander, B., Jaspers, V.L.B., Lepoint, G., Søndergaard, J., Sonne, C., Thorup, K., Tøttrup, A.P., Zubrod, J., Een1, M. & Eulaers, I. Temporal trends of Mercury in three north European white-tailed eagle (Haliaeetus albicilla) populations.




Eulaers I, Jaspers VLB, Bourgeon S, Bustnes JO, Johnsen TV, Leynen N, Nygård T, Pinxten R, Sletten S, Eens M. Is corticosterone in nestling birds of prey body feathers suitable to quantify the impact of environmental stressors?






Communicated Results





In April 2018 (7 a workshop on effects of POPs and multistress was held in Tromsø with national and international participants as part of the EnviStress/Raptor projects.


Based on data from the project a popular article to popular journal Ottar, Tromsø Museum, was published in 2016:

Johnsen, T. & Bustnes, J.O. 2016. Havørn i Nord-Norge. Ottar 309 (1): 25-29.




Interdisciplinary Cooperation


Ecology, physiology, chemistry


Budget in accordance to results


The funding from the Flagship has been essential for continuing the research on raptors, which is especially important for the continuity of the multi-stress perspective.  






Could results from the project be subject for any commercial utilization
If Yes



The project increases our understanding of variation in accumulation and effects of POPs and different elements in northern food chains, both terrestrial and marine.  This will be important in future work on unraveling the potential effects of different contaminants in northern ecosystems.