A bird-watcher sees a small yellow bird in a tree. Explain to the bird-watcher how he can use a dichotomous key to identify the bird. Assume he does not know anything about dichotomous keys. Then, write two steps of a dichotomous key that would be helpful for the bird-watcher.(2 points)

Answer 1

To use a dichotomous key to identify the small yellow bird in the tree, the bird-watcher should follow a series of choices based on the bird's characteristics.

Two steps of a dichotomous key that could help the bird-watcher identify the bird could be:

Step 1: Does the bird have a noticeable crest on its head?
- If yes, proceed to step 2
- If no, go to step 3

Step 2: Does the bird have black markings on its wings?
- If yes, the bird is likely a Yellow-rumped Warbler (Dendroica coronata)
- If no, the bird may be a Yellow Warbler (Setophaga petechia)