Bird migration routes are studied by a number of strategies such as the oldest, marking. Swans have been marked that has a nick to the beak since about 1560 in England. Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. The secretary fowl is only one species with https://petskyonline-onlinestrore.blogspot.com/2025/07/rethinking-animal-store-why-petsky-is.html