secondary extinction

Secondary extinctions occur when the loss of one species leads to the extinction of other species. This can happen directly, such as when parasites lose their host species. More complexly, the removal of a species from a food web can affect other species that interacted with it, potentially causing a cascade of further extinctions.1

These secondary extinctions are particularly evident in species with specialized relationships. For example, certain Hawaiian honeycreepers, which had long beaks adapted to specific flowers, went extinct after their food sources, certain lobelia plants, were decimated by introduced herbivores. Similarly, other species may face extinction if their food sources are depleted due to habitat loss or overharvesting. While ecological experiments demonstrate these cascading effects, pinpointing the exact causes of past secondary extinctions can be challenging due to the complexity of ecological interactions.1