This article draws attention to how birds can be used as indicators for the degree of pollution in the environment, with concerning results. Pollution is a critical reason to put our efforts into bird conservation, as reducing pollutants will no doubt reduce risks for humans. The article certainly makes you think about the amount of chemicals pumped into cattle, sprayed onto crops and used in the manufacturing industry. Furthermore, not only are birds indicators for risks to human health, but also to other commonly poisoned species such as small mammals.
Perched atop many food webs, birds of prey such as eagles and falcons soak up chemicals from the things they eat. That means looking at birds is a proxy for looking at plants, insects, fish, and small mammals over time. Not only that, but about one in five birds migrates, so those birds are sampling pollutants in many parts of the world.