Bird migration routes are already analyzed by a number of approaches such as the oldest, marking. Swans are actually marked having a nick about the beak since about 1560 in England. Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. Other species including merlin Falco columbarius and Eurasian https://petskyonline-onlinestrore.blogspot.com/2025/07/rethinking-animal-store-why-petsky-is.html