Determining The Range, The Volume of Population And Daily Local Relocation Activity of Whooper Swan (Cygnus cygnus L.1758) in Van Lake Basin

Abstract

Objective: In this study, it was aimed to determine status, population size, stop over sites, threats and daily relocation activity of the Whooper swan in the Van Lake Basin. Material and Methods: This study based on the observation data of the Whooper swan that spends the winter in the Van Lake Basin, during 2015 season. The observations were conducted by Point Counts method in the six areas which the species are intensively seen. The data was analysed with the help of IDW (Inverse Distance Weighting) interpolation and point density methods in the Arcmap 10.2 program. Results: It was determined that The Whooper swan came into the Van Lake Basin mostly at the last week of November and left at the last week of March. It is revealed as a winter visitor species that spends about 4 months in the area. However it was seen in many points of the area, it is seen that it lodges in mostly 6 points. During the study, at the beginning of the winter totally 240 individuals were detected as follows; 71 individuals at Arin Lake-the maximum, 63 in Yaylıyaka reeds, 52 in Göründü reeds, 23 in Çelebibağ reeds, 17 in Dönemeç Delta, and 14 in Bendimahi Delta. At the end of the winter, the maximum number of individuals in the whole basin was recorded as 172. Conclusion: At the beginning of the winter 2015, totally 240 individuals were counted in the basin. But it was seen that the number decreased to 172 towards the spring migration. Then there showed up a conclusion that totally 68 individuals (28.34%) in the basin had been perished because of various causes and could not have a chance to return to their breeding sites. It was realized that there happened a population reduction in the basin when compared with the by past studies related to the species. It was presented that hunters, foxes and dogs were the most important role perishing the species. It was detected that the species spends the night along the shore line considered as safe and feed at shallow spaces along the shore. The performed study confirmed once more the Whooper swan overwinters in the Van Lake Basin. Furthermore the study revealed the species should be protected by scientific data.