Which of the following best differentiates lemurs from lorises?

The correct differentiation between lemurs and lorises is that lemurs demonstrate male philopatry, while lorises do not. Male philopatry means that male individuals tend to remain in their natal groups or territory, which is observed in certain lemur species. This behavior has important implications for their social structure and mating patterns.

In contrast, lorises typically exhibit different social dynamics where males may disperse from their natal area. Understanding these patterns aids in the broader comprehension of the social organization and ecology of these two primate groups.

The other options presented do not accurately capture significant differences or represent misleading traits. For instance, while it is true that some lemurs are active during the day and some lorises are nocturnal, not all lemur species are diurnal nor are all lorises strictly nocturnal. Additionally, both groups can have varying patterns of activity depending on the species. The claims regarding the presence of a tapetum lucidum also do not serve as a strong distinguishing factor because both lemurs and lorises may exhibit variations concerning this anatomical feature based on specific species within each group. Thus, the most accurate distinction rests on their behaviors related to male philopatry.