Pet monkeys are pushing Brazil’s tiny mountain marmosets to the brink of extinction
In southeastern Brazil, in cities like São Paulo and Rio de Janeiro, marmosets are commonplace. They are found hanging out on rooftops, hanging from electrical cables and stealing food.
These common marmosets are so widespread that many people assume the invaders are the native species. They are not. The rare endemic animals of the region are instead found in pockets of forest, 700 meters above sea level on the slopes of the mountains.
These primarily arboreal mountain marmosets spend most of their lives in the treetops, and this habitat is rapidly disappearing.
“We have a historical problem in the Atlantic Forest because since the discovery of Brazil over 500 years ago it has been cut and gutted,” Fabiano de Melo, coordinator of the Mountain Marmoset Conservation Center told Euronews Green.
On the million square kilometers of Atlantic Forest that once wrapped around the country’s coast, about 7 percent remains. It is a problem that affects all primates in the region and without a link between these islands of trees, it is difficult for populations to survive.
In addition to the dangers of the ever-diminishing forest, these animals face another threat to their survival: non-native monkeys illegally introduced into the area over the past 30 to 40 years.
Two species are now towards extinction: Buffy’s head marmoset (Callithrix flaviceps) and Buffy’s bushy-eared marmoset (Callithrix aurita).
How do invasive species threaten mountain marmosets?
The founder of the Mountain Marmoset Conservation Program (MMCP), Rodrigo Salles de Carvalho, first noticed the problem during fieldwork for his doctorate in the area.
“I got some perspective of the problem, that Callithrix aurita was suffering and saw how quickly invasive species were growing and taking over. I was really, really scared of that.
No one was addressing the full extent of the problem and Rodrigo knew something had to be done. He spoke to conservation experts across Brazil and the rest of the world, attended workshops on how to care for these creatures, and eventually, the MMCP was created.
So how exactly are these animals from other parts of Brazil put pressure on native species?
Friendlier and “cuter” than the mountain marmosets, they were brought as pets from the north of the country. They were released by owners who were tired of their pets and even by the environmental police, who did not realize the problems they would cause.
Rodrigo recounts stories told to him about misguided officials trying to do what was best for trucks full of animals that had been taken from their owners.
“They didn’t know what to do, so they opened everything up and released all the animals into the closest forest fragments they could find.
Not knowing any better at the time, officers thought that was the best course of action, Rodrigo says. “They were very far from understanding all the ecological issues and they were releasing animals into the wild.”
But the non-native marmosets have adapted very well to the environment of southeastern Brazil – especially the now gutted Atlantic Forest. The marmosets in their mountain centers were invaded from “bottom up,” says Rodrigo.
They reproduce rapidly, competing for habitat and even breeding partners. It is this last point that is perhaps the most worrying – hybrids between species leading to an uncertain future.
There isn’t much research yet, but what has been seen by scientists in the field suggests hybridization could mean the mountain marmoset will be genetically lost.
The first generation of mixing created strong individuals that can often be seen on the streets of Rio de Janeiro. But then future generations seem to disappear. Rodrigo suspects breeding issues are to blame, with more and more hybrid groups appearing and then disappearing in recent years.
“The hybridization process is very fast, it is very fast,” adds Fabiano.
“We just find hybrids because they breed with each other and we lose the genetics of the original species. That’s a huge problem.
How will a captive breeding program save mountain marmosets?
Fabiano is in charge of a new captive breeding program in hopes of securing the future of these endangered animals. Not all endangered primates have a captive breeding program, but the rate at which Callithrix aurita and Callithrix flaviceps are being lost makes this one essential.
“The importance of this conservation breeding program is both to protect them and their genetics and to try to have many animals to reintroduce in the near future,” says Fabiano.
Mountain marmosets are very small animals, often weighing less than half a kilogram. They can have up to two babies, with each mother producing about four babies each year. Conservationists believe this means they can quickly build up a captive “safety population” if they are ever to be reintroduced into the wild.
“I have hope, good hope for the future because we can breed these animals very well,” says Fabiano.
“We actually have good conditions to do it now. We just need to incorporate more animals into our captive program.
At the moment it is a challenge but Fabiano says that when they have the animals to raise, they will be able to create a lot of families to send to other centers, “and after that hundreds of mountain marmosets to put in the nature”.
At the center, these rare and elusive animals can also be better studied to discover more effective ways to save them from extinction. The team will also be the first to try to keep Callithrix flaviceps in captivity, providing a wealth of learning opportunities.
Isabella Normando is the center’s head caretaker. When she started, most of the knowledge she had about keeping these creatures in captivity was very theoretical.
“When we decided to establish this captive colony here in Brazil, we organized a workshop with specialists from Brazil and Europe.”
Much of what they have learned comes from experts at European centres, including Appenheld Zoo in the Netherlands and the Durrel Wildlife Conservation Trust in Jersey. “It’s kind of crazy because it’s a Brazilian species,” laughs Isabella.
Relying on the help of these institutes, she wants the center to become an authority in caring for these animals and reintroducing them into the wild.
“We are inside a university,” explains Isabella, “so we also aim to be an institution that promotes the training of new primatologists and monkey experts.”