How much does Camouflage Affect Predation on Mice by Owls with and without Moonlight? D.W. Kaufman hypothesized that the extent to which the coat color of a mouse contrasted with the color of its surroundings would affect the rate of nighttime predation by owls. He also hypothesized that contrast would be affected by the amount of moonlight. In this exercise, you will analyze data from his studies of owl-mouse predation that tested these hypotheses.

How the Experiment Was Done Pairs of mice ( Peromyscus polionotus) with different coat colors, one light brown and one dark brown , were released simultaneously into an enclosure that contained a hungry owl The researcher recorded the color of the mouse that was first caught by the owl. If the owl did not catch either mouse within 5 minutes, the test was recorded as a zero. The release trials were repeated multiple times in enclosures with either a dark-colored soil surface or a light-colored soil surface. The presence or absence of moonlight during each assay was recorded.

Data from the Experiment

(a)How many dark brown mice were caught In the light-colored soil enclosure on a moonlight night?

(b) How many dark brown mice were caught in the dark-colored soil enclosure on a moonlit night?

(c) On a moonlit night, would a dark brown mouse be more likely to escape predation by owls on dark- or light-colored soil? Explain your answer.

Number of mice caught 40 35 30 25 20- 15 10 5 0 Light coat Dark coat Full moon No moon A: Light-colored soil Number of mice caught 40 35 30- 25 20 15 10 5 0 Light coat Dark coat Full moon No moon B: Dark-colored soil