15.21 Do lizards play a role in spreading plant seeds? Some research carried out in South Africa would suggest so

(“Dispersal of Namaqua Fig [Ficus cordata cordata] Seeds by the Augrabies Flat Lizard [Platysaurus broadleyi],”

Journal of Herpetology [1999]: 328–330). The researchers collected 400 seeds of this particular type of fig, 100 of which were from each treatment: lizard dung, bird dung, rock hyrax dung, and uneaten figs. They planted these seeds in batches of 5, and for each group of 5 they recorded how many of the seeds germinated.

This resulted in 20 observations for each treatment. The treatment means and standard deviations are given in the accompanying table.

Treatment n x s Uneaten figs 20 2.40 .30 Lizard dung 20 2.35 .33 Bird dung 20 1.70 .34 Hyrax dung 20 1.45 .28

a. Construct the appropriate ANOVA table, and test the hypothesis that there is no difference between mean number of seeds germinating for the four treatments.

b. Is there evidence that seeds eaten and then excreted by lizards germinate at a higher rate than those eaten and then excreted by birds? Give statistical evidence to support your answer.