04 April 2017

Like the development and build of the tiger habitat, the design and planning processes we went through were extremely important, as there were many things that needed to be considered for these intelligent and charismatic animals.

So, before our seven Sumatran orangutans make their move to their new habitat we thought we’d let you in on some of the work we did in the lead up to this moment.

Our Sumatran orangutans will be making their move to Islands soon

The main priority for our habitats is to encourage natural animal behaviour and, following a number of years of research carried out in the zoo, we factored a number of things into the design process. As we do with any new habitat, we looked at their wild habitats and aim to reflect this to encourage wild behaviour.

The main thing we needed to consider in the design of a new orangutan habitat are the needs of the animals. For example, orangutans are the world’s largest arboreal animal so they need plenty of climbing opportunities and space to move around. They need height, areas they can climb and different types of climbing.

We’ve worked with Dr Susannah Thorpe from the University of Birmingham as she is an expert in locomotion in orangutans in the wild. It’s been recorded that orangutans amazingly use over 50 types of movement to get between the trees. This can range from basic climbing techniques to a movement where they swing from one tree to another. There are so many different approaches to climbing for orangutans.

That’s why it was important for us to provide as many different types of climbing options in the habitat as possible; this then stimulates more natural behaviours. In our current orangutan habitat we have fixed trees as well as hanging webbing (which works really well as it’s so flexible).

We recently did some research work on sway poles too, again in collaboration with Dr Susannah Thorpe from the University of Birmingham. Sway poles look a bit like bamboo, but are made of carbon fibre. The poles were trialled in the zoo’s current orangutan habitat, where a number of students monitored how much the orangutans used them. In the wild it’s called orthograde clamber (a specific type of movement where primates sway from tree limb to tree limb), a behaviour they do quite a lot. It is important as it requires both mental and physical stimulation as the animals assess the best method to move from tree to tree.

The results were positive and we have placed a number in their new house in Islands. It’s another kind of climbing technique. The sway poles are fixed the opposite way to the hanging webbing, so the orangutans have to work a little harder to use them. Imagine the amount of muscles they need to use in order to get around using the different types of equipment! The poles have also been designed so that they can cope with the weight of both the smaller orangutans and the larger ones.

Another thing the primate team do to keep the animals mentally stimulated. For example, the webbing is moved from time to time so the orangutans then have to work out which webbing takes them where. This again also reflects their natural habitat as no trees would be the same, or move in the same way.

In the wild adult orangutans are largely solitary, probably because of the need to forage for food that is often hard to find a rainforest. Large ‘flanged’ males guard their territory from other adult males, while keeping an eye on the females and their young that he shares his territory with. In zoos, where resources are largely provided for, orangutans are generally much more social. To reflect this we’ve purposely built multiple indoor and outdoor habitats for the orangutans so they have the option to be sociable or find their own space if they so choose.

This means we can separate areas off if the animals want or need more time and space to themselves. This flexibility is critical in habitat design for orangutans.

Another feature the habitat has is keeper access to the roof. This enables our keepers to put food on the roof of their habitat encouraging more natural climbing behaviour, as in the wild they don’t come to the ground very often. It’s nice and simple, but works great! We want to encourage as much arboreal behaviour as possible – that’s why we have the climbing structures, the different feeding methods and the hammocks.

Our orangutans will still go on the ground as there will be some food there, plus they’re naturally inquisitive and there are no predators so they’ll use the space more; but given the option they will spend a lot of time quite high up.

We also have the public viewing windows at high level – this is the case in both orangutan habitats. Although all our orangutans are different some are quite inquisitive and will often interact with the visitors when they want to. By having viewing points at a high level you’re encouraging orangutans to spend more time off the ground supporting that natural behaviour.

It will also be a mixed exhibit – in the Realm of the Red Ape we have lars gibbons in with the orangutans and the interaction between the two species are really positive. The young orangutans like playing with the gibbons.  As this works so well, we’ve done the same thing in Islands, but we have a different species of gibbon; the Moloch gibbon.

For their environment the orangutan habitat will be maintained at around 21°C, with a clear roof allowing as much natural light as possible. We also extend the daylight period so there’s roughly a 12 hour light cycle which is what they get in the tropics. A sprinkler system also ensures we can get the humidity right – even though the orangutans aren’t big fans of the rain and will quickly move for shelter, the gibbons love it and will purposely stay in it! But again it’s to reflect what they would get in the wild.

There’s a lot of thought gone into the design of our new orangutan habitat all to encourage natural behaviour and to ensure the needs of these charismatic and intelligent animals are met.

Learn more about the work we’re doing in the field to protect orangutans here.