Crickets are an indicator of ecosystem health

more sensitive to carbon monoxide than people are. Thus they were routinely taken into mines as men went about their work of extracting coal. Odourless and deadly, carbon monoxide could quickly poison many miners before they even knew what was happening. The canary resolved this problem. If it stopped singing and dropped dead from its perch, this was an indicator that carbon monoxide levels were rising and that evacuation was in order. Now ecologists think they have found a “canary” that could function as a similar indicator of impending disaster for tropical ecosystems—the cricket.As the planet warms, it is becoming ever more important to know which ecosystems are facing radical change and which ones are not. One technique involves finding species that are sensitive to ecosystem change in a given area, but this is tough work. Many of the best indicator species are small and hard to find. Spotting when their populations are just starting to change requires highly skilled specialists to spend a lot of time and resources conducting monitoring operations.