The mute swan (Cygnus olor) and the whooper swan (Cygnus cygnus) are vulnerable species, included in the Red Book of the Republic of Moldova (2015). They are large, robust and heavy birds with long and thin necks. Body weight is 9 kg in females and 12 kg in males, wingspan reaches 2-2.5 m. The swans are the largest water birds and are among the largest flying birds. The mute swan is widespread in Europe and Asia. In the Republic of Moldova, it can be found practically in all water bodies. In recent years, about 800 hatchling pairs have been evaluated at the nesting site. The Black Sea basin is...