Water voles were once one of England most common mammals but have declined by approximately 90% since the 1970s, primarily due to predation by introduced American mink.
Water voles suffer primarily from predation by American mink, which can penetrate their burrow systems and wipe out entire colonies. Unlike native predators, mink hunt in water and can follow voles into burrows. Habitat loss through wetland drainage and river bank modification also reduces viable populations. Isolated colonies cannot recover from local extinction. Mink control programs using rafts and traps have demonstrated population recovery in managed areas. Reintroduction programs require careful preparation of habitat and mink management. Climate change is altering flood patterns along rivers that water voles depend on.