Data analysis
The amount of food eaten (in the test for food
preference) was recorded and calculated to proportion
eaten (in this experiment, the proportion eaten = X/
0.2 g). In addition, the Rodgers’s index for inferring
the food preference was used as following:
The Rodgers’s index (Ri) (7)
Ri = Ai
max (Ai)
When:
Ri = Rodgers’s index of preference for
food item i
Ai = Area under the cumulative proportion
eaten curve for food item i
max Ai = the largest value of the Ai
The homogeneities of variances were tested
and the significant differences between sexes and
among the food items were analyzed by MannWhitney
U-test.