Figure 1. Two moths on a soot-covered tree trunk.
| Figure 1 is a close-up photo of two months on a tree trunk. The photo has a black background because the tree is covered with soot. You can see the white moth clearly, but you will have to look closely to see the dark moth. It is almost totally concealed because its dark color blends with the soot. Concealment is important to moths; they usually fly at night and rest during the day (Brooks 1991). The white moth in this photo would be particularly vulnerable to predation from birds during the day. The moths in Figure 1 are two forms of the peppered moth, Biston betularia. The light form is called typical. The dark form is called melanic. The melanics were quite rare 150 years ago, but they became dominant in some highly polluted areas of England. | Figure 1. Two moths on a soot-covered tree trunk. |
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