Observers often see primate couples sharing caretaking duties, with males often taking a gentle, protective role.
A more recent "may-december" romance, 2-year-old Sui and 10-year-old Kayoran began living together in 2025. Keepers observed a deepening bond as the aging male Kayoran began following Sui more closely and the two started a unique howling "duet" during the 2026 breeding season. japan zoo tokyo animal sex asian anal dog fuck