Disputation: Mohamed Julius Kibaja

PhD candidate Mohamed Julius Kibaja at the Department of Biosciences will be defending the thesis "Behavioural ecology and conservation of Ashy red colobus monkeys (Piliocolobus tephrosceles) in western Tanzania" for the degree of PhD.

Profile picture of Mohamed Julius Kibaja

Mohamed Julius Kibaja

The trial lecture is: "The role of human population growth and capitalism (neoclassical economics) on climate change and biodiversity loss in Africa"

Time and place: July.1, 2022 3:00 PM, Zoom and Nucleus, Bikuben, The Kristine Bonnevie building

Main research findings

The Endangered Ashy red colobus monkeys (Piliocolobus tephrosceles) occur in Uganda and Tanzania. The ecological flexibility of these arboreal and folivorous primates allows them to live in habitats ranging from rainforest to dry savanna woodland, but their populations are rapidly declining mainly due to habitat loss and fragmentation. To obtain information for designing appropriate strategies and identifying priority areas for their conservation, I investigated the behavioural ecology of Ashy monkeys living in contrasting habitats (forest mosaic and dry savanna woodland) and assessed their distribution, population status and conservation threats in Tanzania.

I found that, same as other species of red colobus in Africa, Ashy monkeys flexibly used the different vegetation types within their habitats for feeding and adjusted their movement patterns according to the spatial distribution of their food. Although the species has a wide distribution in Tanzania, I found that anthropogenic threats in all the areas I surveyed are prevalent and in some areas the monkeys are close to being exterminated. Populations that occur outside protected areas are especially threatened. The future of P. tephrosceles in Tanzania depends not only on preserving the species in protected areas, but on the sustainable conservation of their habitats outside these areas.

Adjudication committee

Professor Thomas T. Struhsaker, Duke University

Professor Lynne A. Isbell, University of California Davis

Professor emeritus Reidun Kavli Sirevåg

Chair of defence

Professor emeritus Tore Slagsvold, University of Oslo


Professor Nils Christian Stenseth, University of Oslo

Professor R. Adriana Hernandez-Aguilar, University of Barcelona

Published June 17, 2022 11:20 AM - Last modified Sep. 16, 2022 11:08 AM