Thanks to https://news.ycombinator.com/item?id=25549169 https://news.ycombinator.com/item?id=25549169 I read https://www.historytoday.com/archive/natural-histor

Thanks to https://news.ycombinator.com/item?id=25549169 https://news.ycombinator.com/item?id=25549169 I read https://www.historytoday.com/archive/natural-histories/great-migration-mystery https://www.historytoday.com/archive/natural-histories/great... – which contains much more details but no Pfeilstorch, interestingly.