Taken together, marmosets may not seem in short supply. There are more than 20 species of these tiny monkeys that live high up in the canopies of South American rainforests. But within this large family, several species are struggling.
One of the biggest problems is the fact that marmosets are popular pets, some of which are then released back into the wild. It means that hybrid species, or stronger species from totally different areas, can end up threatening native residents, pushing them out to tiny corners of foliage. Vast deforestation and fragmentation compile the problem, creating physical barriers between different populations, while the threat of yellow fever transmission adds to the deadly cocktail.
The Mountain Marmoset Conservation Programme (MMCP) is particularly concerned about two native species: the critically endangered buffy headed marmoset and the endangered buffy tufted-ear marmoset (known for the skull-like markings on its face and pale tufts of hair over its ears). Both are endemic to the Brazilian Atlantic rainforest and both are suffering, partly at the hands of stronger, introduced rivals. Surveys carried out several years ago by the organisation showed there were only a handful of pure-bred populations left in isolated fragments.
'One of the main factors that threatens both species is the hybridisation process with individuals of the same genus, which were introduced in their distribution areas in southeastern Brazil,' explains Orlando Lopes, a field biologist for the MMCP. 'These invasive individuals reproduce with native species, generating fertile descendants, which causes genetic erosion in medium and long term, contributing to decrease of threatened species populations.'
The problem of people keeping marmosets as pets is far more widespread than just South America. The animals can end up far away from their forest homes. It is technically legal to keep marmosets as pets in the UK for example, where an estimated 4,500 primates are in private hands. Despite warning that they don't make good pets and are wholly unsuitable for it, the RSPCA notes that marmoset monkeys are the most commonly kept and traded species of primate. A 2014 RSPCA report found that 81 per cent of pet primates in the UK belonged to the marmoset group originally from South America.
The threats are mounting up for buffy marmosets. Their mountain forest habitat, known as the South-eastern Atlantic rainforest, is fast disappearing and according to MCCP, as little as seven per cent is now left. The MMCP is determined however that they can be saved. It is working hard to protect the buffy headed marmoset and the buffy tufted-ear marmoset in Brazil, primarily by carrying out surveys and by conducting captive breeding programmes, with the aim of reintroducing some animals and of protecting regional genetic diversity.