Pesticides are a big problem, but is more complex than that. The real conservation of migrating species is a tricky problem. You can do your best effort to save birds in France or Germany just to provide hunters in Malta or Lebanon with plenty of birds (Is estimated than 2.6 millions of migrating birds including many european protected species are killed each year just in Lebanon for example). Is the drama with the vanishing european turtle dove and shrikes for example.

https://conservationaction.co.za/recent-news/stop-killing-le...