Figure 9. Magellanic penguins that had recently fought other penguins were more likely to have blood only on the right side of the face than only on the left side.

The tendency to have blood only on the right side or on both sides increased as the amount of blood increased. Penguins with blood covering less than 1/3 of the face were scored as “little blood”; those with blood covering more than 2/3 of the face were scored as “a lot of blood.”