First observation of a chimpanzee with albinism in the wild: Social interactions and subsequent infanticide

Albinism-the congenital absence of pigmentation-is a very rare phenomenon in animals due to the significant costs to fitness of this condition. Both humans and non-human individuals with albinism face a number of challenges, such as reduced vision, increased exposure to ultraviolet radiation, or compromised crypticity resulting in an elevated vulnerability to predation. However, while observations of social interactions involving individuals with albinism have been observed in wild non-primate animals, such interactions have not been described in detail in non-human primates (hereafter, primates). Here, we report, to our knowledge, the first sighting of an infant with albinism in wild chimpanzees (Pan troglodytes schweinfurthii), including social interactions between the infant, its mother, and group members. We also describe the subsequent killing of the infant by conspecifics as well as their behavior towards the corpse following the infanticide. Finally, we discuss our observations in relation to our understanding of chimpanzee behavior or attitudes towards individuals with very conspicuous appearances.