So the Tangkoko National Park probably owns the monkey.
In many countries, acknowledging ownership implies accepting responsibility. Chances are that they would have to provide the animals shelter in winter, wouldn't be allowed to let them be eaten or die of starvation, would be accountable for damage done by the animals, etc.
So, I doubt they will call themselves the owners of the animals.
Plus many of the monkeys and animals in their park are likely transients that move in and out depending on the season. This would be like claiming ownership of cattle that wanders onto your yard.