Funding for this research was provided by:
Haridus- ja Teadusministeerium (IUT 34-8)
Text and Data Mining valid from 2019-04-05
Received: 29 November 2018
Accepted: 28 March 2019
First Online: 5 April 2019
Compliance with ethical standards
: The authors declare no conflicts of interest.
: Birds were ringed under Estonian Department of the Environment Licence No. 11, and blood samples were taken under Animal Procedures Committee of the Estonian Ministry of Agriculture Licence No. 100.