Why have great apes no acces to trees ?

That's not much of a solution is it? It is a short term enrichment to allow great apes to kill trees but if, after, all you have is a willow bush you have in the end destroyed whatever shade the enclosure had. And it would be many years before those trees, if protected, could grow large enough to again be useful for climbing.

 

@Pertinax is quite right about the orangs at Paignton. There is very little for the orangs to climb on the islands now. They have killed and destroyed all the mature trees in the past 10 years; my photo of Chinta from 2013, shows how they did it.

Chinta eating bark by gentle lemur posted 19 Feb 2013 at 6:33 PM

The bachelor gorillas on the island next door eat a few leaves, but don't do much damage to their smaller trees. Kiondo occasionally climbs up a little.

Kiondo relaxes by gentle lemur posted 28 Aug 2017 at 10:12 PM

When the Monsoon Forest was built at Chester, a mature oak was left in one of the outdoor enclosures for the Sumatran orangs (occasionally alternated with the moloch gibbons). It was wonderful to see the apes in it.

Tuti in the oak tree (looking down) by gentle lemur posted 23 Aug 2017 at 10:25 PM

It was damaged by the apes, and I doubt whether it would have survived until now, but it has had two growing seasons since the orangs were moved out after the fire, so I expect its life will be prolonged. The smaller trees planted in the enclosures had suffered more, but they have had the same benefit. I do think that the zoo ought to have done a bit more to take advantage of the time spent repairing the Monsoon Forest to establish trees in orang and macaque enclosures. The crested macaques were even more very destructive of the original saplings.

Testing a tree to destruction by gentle lemur posted 26 Oct 2015 at 10:34 PM

The chimps and Bornean orangs at Chester have their outdoor enclosures thickly planted with large shrubs, including a lot of evergreens such as laurels, but they also have plenty of telegraph poles supporting rope nets, webbing straps and hammocks. This seems to work well.

 

In moist soil in Europe, willows easily grow in 3 years to provide shade and in 5-6 years to be climbable. Willows grow as thickets of stems, if they are broken, new ones grow from roots, they develop into trees, fall and grow from the broken trunk. Poplars and alders are the same. My worry would be, eventually, whether apes could suffer from eating large amount of willow foliage.

 

I think the big clump of mature trees in Paignton's orang exhibit may be Willow, but they killed them off nonetheless. I agree that willow grows fast and provides good naturalistic cover at lower levels though. There were Alder trees growing on their islands too, which I think have died from the Apes' usage also.

 

Yes, I've never seen Orangs in that tree but only made two or three visits before the Monsoon Forest had to be closed and the Orangs moved out. I wondered when I saw that oak tree in the enclosure whether it would survive longterm.

Talking of the Paignton orangs, I don't think the earlier orangutans, particularly Bulu and Senja, ever ventured into those trees at all, as they were so overweight and habituated to a lack of climbing scope in their former life in London. So the trees stayed in perfect condition for many years. Only when Demo and Mali arrived did the damage start.

 

Chinta and Gigit used to climb a bit but usually just up to platforms. Bulu's son, Nakal, was kept on the small island and started the damage there by stripping bark. But yes, you're right, Demo and Mali were the main culprits, and their daughter is ensuring there is very little left to climb.

 

The orangutan exhibit at Denver has a few huge cottonwood trees that the apes are fully able to access.
https://www.zoochat.com/community/media/primate-panorama-orangutan-exhibit.197741/full
https://www.zoochat.com/community/media/orangutan.383503/full

 

I'm a huge fan of San Diego's orangutan enclosure. The poles they use for climbing structures aren't obnoxiously unrealistic - they are also easy to clean, which the keepers must appreciate. They're quite sturdy as well, which ensures the safety of the apes on exhibit. The ropes also connect mock bamboo poles, giving the exhibit a nice touch.

The hotwire along the edge of the exhibit allows it to have a natural background but eliminates the chances of the individuals on exhibit from escape without having a solid wall.

 

Willows are brittle trees, easily damaged by a large ape moving in one. You could certainly give apes access to such trees and, once they killed the tree and destroyed the shade it provided, hot wire the area off and wait ten years for a suitable tree to regrow. Again providing shade. Then remove the protection and allow the apes to destroy it again in a couple of years. But is this a sensible plan for maintaining the exhibit? Seems like a year or two in the trees followed by a ten year wait is foolish.

 

That's why artificial climbing areas are much more practical in captivity.

 

I wonder if English walnut trees could better live in primate exhibits? They have a strong smell which could make them inedible to monkeys and apes.

 

Perhaps. But a zoo would need a plot of land with mature walnuts and design an exhibit that would not harm the trees - no excavation within the root zone, no added topography. The trees would need to be far enough away from any escape route. So you see that this is a rare situation.

 

I just realized nobody mentioned the worlds best orangutan exhibit yet: Singapore zoo. A group of orangutans there has access to large trees connected by ropes (also going over the visitor path). I wonder what is the secret there? Maybe that the orangutans have access only part time?

 

I have few more ideas:
- Add fast-growing bushes as a distraction. They could take stress out of established tree trunks. I find grass lawns for apes very unrealistic anyway. Even if it can be impossible to recreate a rainforest, one could create a thicket of bushes, bamboo and canes like a secondary forest.
- Install good climbing equipment in addition to trees. I seen that lemurs in zoos and in the wild prefer man-made ropes because they are safer and more convenient to climb. So climbing structures next to branches could take the stress off nearby trees.
- Install and remove electric fence elastically. Damaged trees can be protected temporarily, and others could be then used for climbing.

I think everybody agrees that the current ape exhibits leave much to be desired in naturalness, and could be improved.

 

Apes could potentially throw the walnuts at guests, depending on how the exhibit is designed.

 

More likely eat them!

 

I wouldn't want to deal with the mess that comes with a walnut-throwing ape, so I don't think I'd risk it at all. A tree without projectiles growing from them would be more idealistic. (Any item in their exhibit could be thrown, but I just wouldn't want to add to the risk. I'm not trying to call apes malicious, as it isn't a true statement, it's just something that has to be taken into consideration when zoos are constructing exhibit.)

 

Not gonna lie. The chimps would enjoy this kind of enrichment

 

For sure. They're a little cynical.

 

Could apes safely eat uncooked walnuts? They are poisonous to humans.