• Preuss’s red colobus is found in two populations in West Africa — roughly 3,000 individuals in the Korup–Cross River forest block and none confirmed in the Yabassi Key Biodiversity Area for more than a decade — and faces intense pressure from hunting and habitat loss.
• The Bangka slow loris, restricted to Bangka Island in Indonesia has not been systematically studied for decades and has suffered extensive habitat loss from mining and forest conversion.
• Proper field studies and conservation approaches used for other slow loris species could provide a road map for assessing and protecting the Bangka slow loris.
• For Preuss’s red colobus, a regional action plan is advancing in Nigeria, where monitoring and community outreach are underway, but implementation in Cameroon has been hampered by ongoing civil unrest around Korup National Park.