No More Fly-Byes?

It is claimed that more than 12% of the planet's bird species are in serious danger of extinction (https://www.theguardian.com/environment/2018/apr/23/one-in-eight-birds-is-threatened-with-extinction-global-study-finds). The major problem is the impact of intensive farming (the most threatened species are associated with land where farming is carried out) but other factors such as over-fishing, habitat loss and the introduction of alien species play roles. There is even a suggestion that some insect-eating birds are endangered by neonicotinoid insecticides that appear to endanger honeybees and other pollinators. Some bird species encountering these agents have seriously reduced body stores of fat and are said to be defective in their migration skills. The insecticides may indeed have direct effects on the birds but the possibility must exist that the reduced fat stores simply reflect big declines in available insect prey. Birds with impoverished energy stores may not be effective in their migratory patterns.