To use a dichotomous key, the bird-watcher would need to answer a series of questions about the bird's characteristics, such as its size, color, and shape of its beak. Based on these answers, the key will lead the bird-watcher to the correct identification of the bird.
Step 1: Is the bird predominantly yellow or a different color?
Step 2: Does the bird have a black stripe on its head?
If temperatures fall due to climate change, rainbow trout may benefit from having genetic adaptations that allow them to thrive in colder water temperatures. This variation could help the trout survive by enabling them to withstand the new, colder conditions in their environment.