Table 1 Effects of predictors on the index of (A) grooming received and (B) grooming given and on (C) the proportion of grooming events, including the perianal area.

For each predictor, we calculated the sum of Akaike weights of the models, including the predictor (importance) and compared it to the expected value under the assumption that all tested models have equal Akaike weights (expected ratio) to show the plausibility of each predictor. Plausible predictors (in bold) are those with an importance greater than the expected ratio. The estimate coefficient associated to each predictor variable and its SEM are reported. Dominance in interaction with sex is not shown in the tables because this interaction was never included in the set of best models.

PredictorsImportanceExpected ratioEstimateSEM
A
  Age0.990.50.050.01
  Protozoan richness0.60.5−0.100.06
  Sex0.530.33
    Female0.020.27
    Male0.320.27
B
  Sex0.980.33
    Female0.770.13
    Male0.020.12
  Age0.30.50.010.01
  Protozoan richness0.250.50.010.04
C
  Protozoan richness0.860.5−0.840.37
  Age0.450.50.150.11
  Sex0.170.5
    Female1.312.13
    Male0.812.33