Slow and steady wins the race with primate release

Every year, rescue centres release animals, that are deemed ready, into the wild.

This is done based on the assumption that the animals will thrive most in their natural habitat, but this has never been scientifically tested with primates, until now.

Animals’ well-being

Our team, working with Disney’s Animals, Science and Environment and the Jane Goodall Institute, found that a very gradual phased re-introduction of mandrills into the forest with post-release support improved the animals’ well-being.

After being released back into their natural habitat, the animals’ stress response was lower in the wild than it had been when they lived at the sanctuary.

Stress reduced

The International Union for Conservation of Nature (IUCN) recommends a gradual release and post-release monitoring for primates but this is often not achieved due to cost and time restrictions.

This study provides evidence that slow and steady does win the race when it comes to the well-being of the animals, who had been orphaned by hunting and rescued by the authorities in the Republic of Congo.

After one year in the wild, the mandrills’ stress response was about half what it had been in the sanctuary, suggesting that the mandrills were doing well in the wild.

Careful release process

Working in the Republic of Congo, the team transferred 15 mandrills from the Tchimpounga Sanctuary to a pre-release enclosure in Conkouati-Douli National Park, and then into the park itself.

The release process involved the mandrills spending time in a pre-release enclosure built in the forest, extra food, observations of the animals’ condition, and interventions to remove animals that were not doing well. Their stress responses were measured at every stage using faecal samples.

Of the 15 mandrills released, all survived and two babies were born, with only three of the original group returned to the sanctuary as their transfer was not successful.

Find out more

• The research was led by Professor Jo Setchell at Durham University working with then PhD student, Dr Miles Woodruff, in collaboration with colleagues at Disney’s Animals, Science and Environment and the Jane Goodall Institute.

• You can read the research paper in Conservation Physiology.

• The study was funded by the Jane Goodall Institute and private donors.

• Our Anthropology Department is one of the largest in the UK and is ranked 23rd globally (QS World University Rankings by Subject 2023). Fieldwork is core to our taught programmes, and we offer research-led teaching and hands-on experience to equip our students with the knowledge and skills they need for a successful future. Feeling inspired? Visit our Anthropology webpages for more information on our undergraduate and postgraduate programmes. 

Image credit: Mandrill Re-Introduction Project, Jane Goodall Institute Tchimpounga