Shoals of sulphur mollies blanket the water surface of toxic sulphur springs in Mexico. The tiny fish survive attacks of birds through creating collective waves. New research now shows that their avian predators are adapting too, changing where they attack to avoid triggering the fish’s powerful group defence. The fish, in turn, appear to fight back with a surprising form of collective “memory.” 

This study provides high-resolution, field-based evidence of the importance of accounting for short-term flow interruptions in river management strategies. It demonstrated that a one-day streamflow interruption of the side channel of the River Erpe caused a significant decrease in diel surface water oxygen amplitude and porewater oxygen concentrations, as well as a metabolic shift after rewetting.

Through competition for food or attacks, invasive species can cause severe suffering to native wild and farmed animals, but they can suffer too. The authors present a framework which can be used to identify and assess the animal welfare impacts of biological invasions.