Large carnivores are crucial for keeping ecosystems healthy. Globally, however, their numbers are dropping due to habitat loss, conflicts with humans, and illegal hunting. Moving these animals to new, potentially safer places, known as translocation, can help protect them.

Translocations can have different conservation purposes. Often, they’re used to reinforce an existing population of animals or reintroduce a species to an area they once inhabited, with growing interest in using orphaned and rehabilitated animals from the illegal wildlife trade or zoos in these efforts. Sometimes, translocations are carried out to reduce conflicts between humans and animals.

Much hinges on the success of these interventions. Therefore, this study looked at different translocation projects from around the world to find out what factors make them successful, so that future conservation efforts can be improved.

Researchers conducted a literature review and gathered unpublished data on translocation projects. They focused on the time period between 2007 and 2021 to minimize overlap with previous studies. This resulted in a final dataset of 33 different projects representing 18 species and 297 individual animals across five continents, although 17 individuals had to be excluded due to a lack of post-release monitoring.

The researchers considered a move successful if the animal survived for more than six months. They looked at whether the animals were born in the wild or in captivity, their species, age, and sex, how they were released, and how they were monitored after the move.

From their analysis, the researchers found that translocations have become a more common conservation approach over time, with the number of countries involved increasing from 11 pre-2007 to 22 post-2007. Overall, about 66% of the translocations were successful, ranging from 62% in Africa to 94% in South America. Success rates have also increased over time: for wild-born carnivores, it increased from 53% before 2007 to 70% after 2007 and for captive-born animals, it doubled from 32% to 64% over the same period.

Success was not uniform across species. Maned wolves, pumas, and ocelots had a 100% success rate, while African lions and brown hyenas had the lowest success rates at around 50%. Age was also a factor, with younger animals (two years of age or under) having higher success rates than older ones. Sex didn’t appear to influence translocation success.

Soft releases, where animals are given an opportunity to get used to the new location gradually before being released, were 2.5 times more likely to succeed than hard releases.

Encouragingly, about 37% of translocated animals engaged in reproductive behavior, meaning they were found to be mating, raising young, or in the case of solitary species, accompanying an individual of the opposite sex.

While success rates have improved over time, 34% of translocations still fail, which the researchers argue is a high mortality rate for species already under threat. Thus, future translocations should focus on:

• Pre-release population surveys: Understanding current carnivore populations before releasing translocated individuals is key to minimizing conflict and competition between animals post-release.
• Soft-release techniques: Although more expensive, gradually introducing animals to their new environment helps them survive better than sudden releases.
• Post-release monitoring: Tracking animals for longer periods of time and with improved technologies will provide more and better data and may be particularly insightful for understanding reproductive behavior. Beyond survival of translocated individuals, reproduction is necessary to establish or boost carnivore populations.
• Adaptive management: Translocation projects should be flexible and ready to change strategies based on new data.
• Community engagement: Involving local stakeholders can reduce conflicts and increase support for translocations.
• Policy support: Strong government and community support are needed to help translocations be successful.

By combining these methods with practical strategies and community support, we can make translocations more successful and help global conservation efforts.