Answer: It is called 'resource partitioning'.
Step-by-step explanation: The distinct nature of the two species allows them to co-exist in the same premise without any conflict. When one of the species (the diurnal) is out in search of food, the other prefers dwelling on the tree because of its nocturnal nature. Therefore, they are not confronted with each other as predators.
The food that is available at night is consumed by the nocturnal species and the food available during the daytime is eaten up by diurnal species. Hence, there is no competition.