Improving Primate Welfare Through Gradual Release With Post-Release Support

Primates are among the most endangered and threatened animals in the world, due to habitat loss, hunting, poaching, and illegal wildlife trade.

Many primates are rescued and rehabilitated by wildlife sanctuaries and rescue centers across Africa and other regions, where they receive medical care, nutrition, and socialization.

However, the ultimate goal of many sanctuaries and rescue centers is to reintroduce these primates back into the wild, where they can live freely and contribute to the conservation of their species and ecosystems.

Reintroduction is a complex and challenging process that involves careful planning, preparation, and evaluation.

It also requires post-release support and monitoring to ensure the well-being and survival of the released animals.

However, there is limited scientific evidence on the effectiveness and impact of primate reintroductions on animal welfare and conservation.

A recent study by researchers from Durham University, Disney's Animals, Science and Environment, and the Jane Goodall Institute has addressed this gap by evaluating the well-being of a group of mandrills who were gradually reintroduced into the wild with post-release support in Congo.

The study has shown that this approach improved the well-being of the mandrills and facilitated their adaptation to their natural habitat.

How to Measure Well-being in Reintroduced Primates

(Photo : GUERCHOM NDEBO/AFP via Getty Images)

Well-being is a multidimensional concept that encompasses the physical, mental, and emotional aspects of an animal's life, as per Phys.org.

Well-being can be influenced by various factors, such as health, nutrition, environment, social relationships, and stress.

Measuring well-being in wild animals is challenging, as it requires reliable indicators that can be assessed non-invasively and objectively.

One of the indicators used in this study was cortisol, a hormone that is released in response to stress.

Cortisol can be measured in hair samples, which reflect chronic stress levels over a period of time.

The researchers collected hair samples from 14 mandrills who were rescued from the illegal wildlife trade and rehabilitated at the Tchimpounga Chimpanzee Rehabilitation Centre in Congo.

The mandrills were gradually reintroduced into the wild using a phased approach that involved spending time in a pre-release enclosure built in the forest, receiving supplementary food, being observed for their condition and behavior, and being intervened if needed.

The researchers compared the cortisol levels of the mandrills before and after their release into the wild.

Another indicator used in this study was behavior, which can reflect an animal's emotional state, preferences, and coping strategies.

Behavior can be observed directly or recorded using camera traps or GPS collars.

The researchers observed the behavior of the mandrills during their time in the pre-release enclosure and after their release into the wild.

They recorded their activity patterns, feeding habits, social interactions, and exploration behaviors.

Also read: Ecological Opportunity Prompts Tool Use Among Primates

What The Results Reveal About The Reintroduced Mandrills

The results showed that the gradual reintroduction with post-release support improved the well-being of the mandrills, as per the Big News Network.

The cortisol levels of the mandrills were lower in the wild than they were at the sanctuary, indicating that they experienced less stress in their natural habitat.

The behavior of the mandrills also changed after their release into the wild.

They became more active during the day, spent more time feeding on natural foods, formed stable social groups, and explored new areas.

The results also revealed that some factors influenced the well-being of the mandrills more than others.

For example, sex, age, and personality affected how well the mandrills adapted to their new environment.

Males had lower cortisol levels than females, possibly because they faced less competition for food and mates.

Younger mandrills had lower cortisol levels than older ones, possibly because they were more curious and flexible.

Bold mandrills had lower cortisol levels than shy ones, possibly because they were more confident and resilient.

The study concluded that the gradual supported release of primates into the wild can be an effective strategy to improve their well-being and facilitate their adaptation to their natural habitat.

The study also suggested that measuring cortisol levels and behavior can provide useful indicators of well-being in reintroduced primates.

The study also highlighted the importance of considering individual differences among primates when planning and evaluating reintroductions.

The study also pointed out some limitations and challenges of primate reintroductions.

For example, reintroductions are costly and time-consuming, requiring long-term commitment and collaboration among various stakeholders.

Reintroductions also pose potential risks to both released animals and wild populations, such as disease transmission, genetic mixing, human-wildlife conflict, and habitat degradation.

Therefore, reintroductions should be carefully planned, implemented, and monitored, following the guidelines and best practices of the International Union for Conservation of Nature (IUCN) and other relevant organizations.

Related article: The World's Primates Threatened With Extinction Crisis