Funding for this research was provided by:
Natural Science Foundation of Henan Province (162300410129)
National Basic Research Program of China (973 Program) (2017YFD0501305)
National Natural Science Foundation of China (31330079)
Text and Data Mining valid from 2020-01-07
Received: 19 September 2019
Accepted: 3 January 2020
First Online: 7 January 2020
Ethics approval and consent to participate
: This study adhered strictly to the Regulations for the Implementation of the Peopleʼs Republic of China on the Protection of Terrestrial Wildlife and the Law of the Peopleʼs Republic of China on the Protection of Wildlife. The research protocol was reviewed and approved by the Research Ethics Committee of Henan Agricultural University. Samples were collected with the help of the staff at the Sanmenxia Management Office of the Yellow River Wetland National Nature Reserve in Henan Province. No <i>C. cygnus</i> were harmed in this study.
: Not applicable.
: The authors declare that they have no competing interests.