Funding for this research was provided by:
Ministerstwo Nauki i Szkolnictwa Wyższego (FVS PULS 506-511-05, from the Faculty of Veterinary Medicine and Animal Science, Poznań University of Life Sciences, Poland, Institute of Zoology, 507.511.34/2015 of the Young Researcher Program of the Faculty of Veterinary Medicine and Animal Science, Poznań University of Life Sciences, Poland)
Received: 28 August 2020
Accepted: 11 March 2021
First Online: 25 March 2021
: Compliance with ethical standards: we were issued permits for working with toads from the Regional Director of Environmental Protection (permit nos. WPN.6401.57.2014.IW and ExternalRef removed.I). All skeletochronology procedures were performed with permits from the General Directorate of Environmental Protection (permit no. WZP-WG.6401.02.4.2016. JRO) and the II Local Ethical Commission for Animal Experiments in Wrocław (permit no. 2/2015).
: Not applicable.
: The authors declare that they have no competing interests.