The influx of chimpanzees being taken in by African sanctuaries and rescue centres shows no sign of letting up.
Despite the tireless efforts of conservationists and scientists to safeguard these apes in the wild, many new arrivals share a common bond, they are the by-products of either the illegal bushmeat trade or pet trade.
Adult chimpanzees (Pan troglodytes) are killed for meat and the surviving infants often end up on sale as pets. Those that are confiscated by law enforcement are taken to sanctuaries for care – but can African sanctuaries and rescue centres afford to sustain these every increasing numbers?
A new study, published in the International Journal of Primatology, has looked at 11 Pan African Sanctuary Alliance (PASA) member centres and has predicted their carrying capacity for chimpanzees and created a road map for long-term resource, infrastructure and financial planning.
Lead author Dr Lisa Faust, a research biologist with Chicago’s Lincoln Park Zoo in America said, “The most sobering part of this study is realising that most of these institutions already report being at capacity or close to capacity, and yet on average the group of sanctuaries are collectively faced with accepting 56 new chimpanzee arrivals every year, most of them under the age of two to three years old.
“Because chimpanzees are long-lived, this means that most of the sanctuaries will need to sustain or increase their current size, because they will continue to accept new arrivals as part of their commitment to chimpanzee welfare and law enforcement.”
Chimpanzees are an endangered species, and while poaching is illegal it remains a major problem threatening their continued survival.
PASA a non-profit organisation that supports sanctuaries across the continent provides rehabilitation to endangered primates.
Doug Cress, executive director of PASA said, “It’s easy to get caught up in the day-to-day fight for survival and lose perspective. This study is so important because it allows us to step back and see where we’ll be in the coming years and decades and to plan accordingly. Population modelling on this level is a wonderful tool.”
The study analysed historic demographic patterns and projected future population dynamics of these select sanctuaries which housed (at that time) 760 chimpanzees. The median age was 9 years old, with 76 percent of the population being less than 15 years.
Lincoln Park Zoo chimpanzee behavioural researcher Dr Steve Ross, co-author on the research, explained that as chimpanzees age and reach sexual maturity, group dynamics shift, making social structure an important component for future management plans for PASA sanctuaries.
“Older chimpanzees can be subject to aggression and social disharmony, especially in large groups,” he explained. “This could be further exacerbated by the influx of adolescents, so managing group sizes and dynamics will be crucial for these sanctuaries.”
“We found there to be an exponential relationship between population size and resource need because groups sizes cannot grow indefinitely,” explained Faust.
“Our goal with this research is to provide PASA with a road map for the potential future management challenges they may face. It should help long-term planning and increase their ability to be stewards for the apes they take in and advocates for those they work to protect in the wild.”
Confiscated apes cannot simply be re-released back to the wild. Experts say that a chimpanzee that survives the physical and emotional trauma of capture can take years to recover and reintroduction projects are costly and complicated.
“Reintroducing primates is not simple,” Cress explained. “Deforestation and poaching make many areas unsuitable for reintroduction, and human encroachment has resulted in communities living in many of the national parks and protected areas. Also, it can be difficult to build a social group of chimpanzees that is physically and emotionally strong enough to survive a reintroduction. That’s why the number of released animals remains relatively small compared to the number of orphans in need of care. Lifetime care in sanctuaries is the most frequent option for orphaned primates.”
PASA has so far put more than 50 chimpanzees back into the wild in Congo and Guinea. Over the next few years there are three Cameroon sanctuaries hoping to double that number through reintroduction programmes.