On April 9, the International Union for Conservation of Nature declared the emperor penguin to be an endangered species.
| Photo Credit: KSL
A sentinel species is a species whose members’ health signals the condition of the ecosystem in which they live.
Scientists monitor them because they are among the first to respond to stressors in their environment, such as pollution and disease, and their response also tends to be more apparent than most other species. In other words, they can provide early warnings of ecosystem decline.
Published – April 12, 2026 03:17 pm IST
