In vivo deciduous dental eruption in LuiKotale bonobos and Gombe chimpanzees

Abstract

Existing data on bonobo and chimpanzee dental eruption timing are derived predominantly from captive individuals or deceased wild individuals. However, recent advances in noninvasive photographic monitoring of living, wild apes have greatly expanded our knowledge of chimpanzee dental eruption in relatively healthy individuals under naturalistic conditions. We employ similar methods to expand on this knowledge by reporting deciduous dental eruption ages in living, wild bonobos and chimpanzees from LuiKotale, Democratic Republic of the Congo and Gombe National Park, Tanzania, respectively. Deciduous dental eruption ages in our sample generally fall within the range of variation previously documented for captive chimpanzees. We also found substantial variation in deciduous canine eruption timing, particularly among bonobos. One bonobo had a deciduous canine present by 227 days old while another did not have a deciduous canine present at 477 days old. As more data accumulate from these populations, future studies should consider sources of variation in deciduous canine eruption timing and relationships with other aspects of life history.