When I first saw a marmoset I was very surprised. I had never seen a monkey so tiny!
Now I work with a group of four males: Harry, Draco, Potter and Malfoy. Draco is the alpha male and he often behaves as a real leader by puffing his fur to look bigger and scarier. Harry is the most curious of the four. He always jumps on my shoulder to see what kind of food I brought this time.
The other two, Malfoy and Potter, are not that focused on us caretakers. But when you have something that they really like or when a strange and new object is introduced in their enclosure, they will also jump on your shoulder and start to make noises.
It is a really nice group to work with. They are all very different and comfortable with the presence of the caretakers.
What is a marmoset?
The common marmoset is one of the smallest monkey species. They belong to the group called New World monkeys. You can identify them because of their white ear tufts and their striped tail.
For a lot of people it is very difficult to differentiate the individuals in a group, because they all look alike! For me it was the same when I began to work with monkeys, but after a few days I started to notice different fur patterns, behaviours and different faces. There are no two monkeys the same, like there are no two people the same. You just need to look closer.
Facts about marmosets
- They are around 21 cm long.
- Their tale is longer than their body.
- They form small family groups (3-15 individuals) called troops.
- They spend most of their time in trees.
- Their natural habitat is in Brazil.
- They are active during the day.
- They can live up to 12 years in the wild and 16 in captivity.
- Threats that they face are habitat destruction and the pet industry.
- Pregnancy is 150 days and they normally give birth to twins.
- The whole troop will take care of the babies.
How do they behave?
My group is very active; they groom, play, jump, fight and make a lot of noise.
With monkeys, grooming has not only a hygiene function, but also an important social behaviour purpose. They use it to bond, reinforce social and family structures and resolve conflicts.
They sometimes fight and during summer some of the fights in our troop got fiercer. To prevent injuries and a definitive separation, we started to give them more enrichment so that they would spend more time focused on something else. We also scattered food in the enclosure enough for each of them and to prevent that the lowest in rang wouldn’t get any. And we made an extra house for them to sleep in if they didn’t want to sleep together.
With all these changes, the situation improved and we saw that they would only fight a little when we gave them their food.
To spice up their lives we put new branches to climb, hammocks, new smells, grasshoppers to catch, etc. With these things we keep them active and stimulate their natural behaviours.
Another interesting thing is that they are very vocal animals which make a lot of different high pitched noises. Some of the sounds are so high that humans can´t hear them. They have different sounds when they are playing or get stressed, when they are scared or happy or when they are calling other members of the group. This is so interesting, that I could write a whole new post about the sounds they make in different situations, how to understand them and what this can tell you about their welfare.
What do they eat?
Preparing food for them is one of the most important things I do, because they need a varied diet. They get fed three times a day, unlike other animals at our zoo, except for the tamarins, their close cousins.
For breakfast they always get tamarin cake and some fruit. Tamarin cake is a complementary food for marmosets and tamarins. It has a lot of vitamins, minerals and other components that these animals need.
Their lunch is composed of fruit or boiled vegetables and their dinner is some protein like worms or boiled egg.
During my years working with 
these animals I have seen that, like humans, every marmoset has its favourite food and they don´t like the same things. But they all love bananas, grapes, mango and meal worms.
And then there is the Arabic gum. Marmosets are gum eaters. With their sharp teeth they make holes in trees to get it out. They spend a lot of time doing this. It doesn’t only keep them busy, it is also a source of energy, calcium and minerals. You can buy Arabic gum in powder form and mixing it with water you get the sticky stuff. All the marmosets I have known love this, it is their ultimate favourite and they will fight for it. I always try to put the gum on different spots so they can all enjoy it.
Types of marmosets
There are many different marmoset species. Some of the species are:
- The black-tufted marmoset, that looks a bit like the common marmoset, but with black ear tufts.
- The pygmy marmoset is the smallest marmoset and also the smallest monkey in the world. They are 12 to 16 cm and their tale is about twice the size of their body.
- The Goeldi´s marmoset is the largest marmoset, with a length of 21 to 23 cm. They are almost completely dark brown or black with some white areas on the face.
It is not a pet
Marmosets are often kept as pets. Baby marmosets are being taken far too early from their mother by breeders and sold to people who don´t really know how to take care of them.
Marmosets are wild animals and they have specific needs. It is very difficult to create a good environment for them. They live in groups and interact a lot among each other. Keeping these animals alone in a cage is without any doubt a cruel destiny.
They are highly intelligent and in captivity they will get easily stressed or bored, showing abnormal behaviour.
A lot of rescue centres and animal sanctuaries have to take care of them after their owners abandon them. Sometimes the police have to step in, because the owner doesn´t take good care of the marmoset or its living conditions are too bad.
For these reasons, and a lot more, marmosets, monkeys and other exotic animals shouldn’t be kept as pets. They belong in their natural habitat.
There is a very good campaign started by the Dutch foundation Stichting AAP called “The positive list”. It is a list with animals that are suitable and legal to be kept as pets. Only if you can take good care of them, of course!!
All other animals that are not on the list are not allowed to be kept as pets.