Explanation:
We can hypothesize that sociality of these primates provide survival benefits the survival of the eagle.
The presence of bones in eagle's nest prove that the eaglwe had been feeding on the primate species. When analysis revealed that these primates lived alone it was easy to assume that their solitary existence made them easy prey for the eagle. So, we can say that sociality i.e. social interaction of the primate benefited the eagle's survival.
