What is an indicator species?

An indicator species is a species that is highly sensitive to ecological changes in its environment. This means that its presence, absence, health, or abundance in an area is often tied to what is happening in this habitat.

An indicator species’ early responses to ecosystem changes can give insight into how other species may react in the future, such as its reaction to changes in temperature, pH, moisture, or other critical conditions.

Amphibians, for instance, are highly susceptible to changes in water quality. A sudden decline in a frog population may indicate the presence of harmful toxins in the water supply that could further affect other organisms.