In the second half of the 19th century, a scientific ornithology emerged that was heavily influenced by empirical research. During a visit to the spit in 1896, ornithologist Johannes Thienemann witnessed a bird migration as massive as had never been observed in Germany before. The narrow strip of land constricted the flight paths of the birds, which avoided open water: at peak times, up to two million birds a day. At Thienemann's initiative, an ornithological-biological observation station was established in Rossitten in 1901, located in the southern third of the elongated peninsula. In 1923, the Kaiser Wilhelm Society for the Advancement of Science took over the station and integrated it into its research network. Thienemann retired in 1929, and Oskar Heinroth took over formal leadership from Berlin.