Dippers are specialist freshwater birds that walk underwater to catch invertebrates, making them highly sensitive to river acidification and invertebrate community collapse.
Dippers in acidified river systems cannot find adequate food, leading to chronic nutritional stress affecting both adult condition and chick provisioning success. Young dippers learning to forage in rivers depleted of invertebrates face higher starvation rates. Pollution events from agricultural runoff kill invertebrate communities rapidly, leaving dippers with no food source for extended periods. Drought conditions reduce flow velocity, eliminating the well-oxygenated riffle habitats that support the invertebrate communities dippers depend on.