To test this hypothesis, we collected data on meat sharing and copulation frequency in a group of wild chimpanzees in the Taï National Park, Côte d'Ivoire between 2003 and 2006.
No significant differences among longicornis, giraulti, F2[ g], and F2[ l] males were found for any step in courtship, except in copulation frequencies with longicornis females (Fisher Exact Test, p=0.001).
Differences among the four types of males in copulation frequencies with vitripennis females were highly significant (Fisher Exact Test, p=0.002).
Copulation frequencies with vitripennis females ranged from 17% of total males for F2[ g] males to 100% for vitripennis males.
Copulation frequency assays were performed in single-pair assays in chambers of 1 cm diameter for 10 min under constant light.
Understanding female choice and male-female meat sharing in species in which copulation frequency can be easily measured and dyadic transfers of meat can be directly quantified is likely to give us insight into the mechanisms driving the latter relationship in humans.
We did this to test alternative explanations to having a relationship between meat sharing and copulation frequency and additionally to reduce, in each case, the number of predictor variables included in the model.
Copulation frequency was calculated as percentage of flies in each condition that successfully copulated during the 10 min assay.
Overall, the predictor variables included in the model had a significant effect on copulation frequency (likelihood-ratio test: χ2 = 27.64, df = 4, N = 30, p<0.0001).
Overall, the predictor variables included in this model had a significant effect on copulation frequency (likelihood-ratio test: χ2 = 32.83, df = 7, N = 30, p<0.0001).
