In Cartagena, Colombia, an unlikely bond has formed between a dog and a capuchin monkey. Someone introduced the dog, who’d recently lost her litter of puppies, to the monkey, who was in need of rearing. The two took to one another and are now inseparable, with the monkey riding on the dog’s back wherever she goes.

There is, however, an unfortunate dark side to this seemingly sweet story of friendship. The monkey was illegally stolen from its mother in the wild at a very young age due to demand for baby capuchins on the black market.

Environmental officials have taken custody of the pair. Now that the monkey has been separated from its natural environment, however, they’re unsure if it can be released back into the wild. Some contend that the best thing for the dog and monkey is to keep them together. Either way, there is no easy answer.

Although unlikely friendships between wild and domesticated species are heartwarming on the surface, this story reminds us of the unfairness of interfering with wildlife and the urgent need to end the black market animal trade.