A study by the University of Exeter has highlighted the problems of reintroducing animals to the wild for conservation projects. Published online in the journal Biological Conservation, the research highlights the low survival rates of captive carnivores that are released into their natural habitats. On average only one in three captive-born carnivores survives in the wild, with most deaths related to human activities.
Recent high-profile conservation projects have involved reintroducing wolves into the Scottish Highlands, bringing red kites back to England and reintroducing golden lion tamarins to Brazil. Most of these animals were born in captivity, with zoos playing a major role in such projects, while other schemes involve moving wild animals to new areas.
This study reviewed 45 case studies, involving 17 carnivore species, and found that only 30% of captive animals released survived. Over half the deaths were caused by humans in incidents such as shootings and car accidents. The animals were also more susceptible to starvation and disease than their wild counterparts and less able to form successful social groups.
Kristen Jule, lead author on the paper and University of Exeter PhD student, says: "Animals in captivity do not usually have the natural behaviours needed for success in the wild. Their lack of hunting skills and their lack of fear towards humans, for example, are major disadvantages. We have suspected for some time that captive born animals fared less well than wild animals, but here it is finally quantified, and the extent of the problem is critical."
The research team highlights the need for these projects to be reassessed so that animals are better prepared for living in their natural environment. This could include reducing contact with humans, creating opportunities for hunting and encouraging the formation of natural social groups, while the animals are still in captivity. The research also raised the need for long-term monitoring of released animals, so that success could be measured over several years. In addition, the paper points to the need for engagement with local communities before any reintroduction, especially as most carnivore extinctions were originally caused through conflict between animals and humans.
Kristen Jule continued: "Despite the problems raised in our research, I believe reintroduction projects are vital to conservation efforts. In some cases, the animals being released no longer exist in the wild because of human development or conflict. If we are to try and redress the balance, it's important for us to help provide captive born animals with the opportunity to gain the skills that they will need to survive in the wild. The next step is for scientists, conservationists and animal welfare groups to develop guidelines to help captive animals prepare for a new life in the wild."