Genetics and community-based restoration can guide conservation of forest fragments for endangered primates

•There is no evidence of genetic population structure in Ashy red colobus monkeys inhabiting a highly fragmented landscape.•A “stepping stone” model could maintain connectivity between the main forest and the fragments improving the viability of red colobus populations.•Forest stepping stones can be established through restoration efforts of non-arable areas between fragments and the park.•A community-based forest restoration effort can benefit multiple stakeholders and increase the conservation value of forest fragments.