Funding for this research was provided by:
The National Research Centre, Poland (2011/01/B/NZ9/04352)
The Ministry of Environment and Food of Denmark
Article History
Received: 9 June 2017
Accepted: 7 March 2018
First Online: 27 March 2018
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: All applicable international, national, and/or institutional guidelines for the care and use of animals were followed by the authors.
: All necessary permits for sampling and observational field studies have been obtained by the authors from the competent authorities and are mentioned in the acknowledgements, if applicable.