Funding for this research was provided by:
Academy of Finland (289456)
Received: 4 November 2019
Revised: 21 September 2020
Accepted: 25 September 2020
First Online: 13 October 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: Birds were caught and handled by personnel with a ringing license. All experiments complied with the Finnish law on animal experiments and were approved by the animal experiment committee of Southern Finland. Bird handling was done with the highest possible care.