Wild chimpanzee termite mound inspections converge with the onset of rain

How and when to inspect for hidden and ephemeral food sources presents a cognitive challenge for wild animals. Observational data suggests a high degree of seasonality in the chimpanzees' preferred termite prey at the site of Issa Valley, Tanzania. This allows us to consider hypotheses on chimpanzees' ability to predict termite activity and to efficiently forage for termites based on seasonal rainfall trends. We analyzed 6806 min (113 h) of camera trap videos recorded over 48 months (from 2016-2019) from termite mounds and documented chimpanzee inspection behavior in the Issa Valley, western Tanzania. Our results suggest that Issa chimpanzees initiated foraging for termites, adjusted the period in which they prepared tools in advance, and inspected termite mounds in association with rainfall trends. Chimpanzee planning and foraging behaviors have implications for hominin decision making, forethought, and seasonal landscape utilization.