Animal Exhibit Design - Cages vs. Plexiglass vs. Islands

Historically, most zoos kept animals in small concrete enclosures with metal cage bars, with major shifts towards giving animals more space, enrichment, props, and foliage, separating visitors from animals with moats and plexiglass viewing windows in order to maximize unobstructed viewing.

As an animal photographer, the most frustrating part of a zoo visit is the cages (mostly housing primates, birds, and smaller carnivores these days). It is often impossible to get a good photo of an animal's face due to the cage bars and chain-link fences in the way. There are also often short fences or thorny hedges in front of the cages to prevent visitors from harassing the animals, but also this prevents photographers from aiming their lenses through the cage bars. What are the advantages of keeping animals in cages as opposed to islands and areas with a combination of fences and plexiglass? It appears that older zoos, lower-budget zoos, and zoos in developing countries tend to use cages more than other forms of exhibit design.

I had a discussion with a friend about keeping primates (specifically gibbons) in cages versus islands, and he said cages have the advantage of allowing gibbons to climb and brachiate, whereas island climbing structures may be inadequate, plus there is a risk of them drowning in moats.

 

I prefer glass IF it's kept clean. I can do a lot with photoshop for fencing, I can't do anything if the glass is too dirty.

An example, from Metro Richmond. This spot was the only little bit where you could view anything at all.



Glass can also cause issues with reflections and bright sunlight.

Islands and big moats are some of my least favorite things.

 

There are good and bad things to all variations you mentioned. Typically in cages environments they are much closer than most other types of exhibits and can get good shots without compromising bokeh. Some of the traditional cages do tend to have thicker bars or chain link fencing that can make it hard to focus your points when shooting. Especially made almost impossible when the sunlight is hitting from your area of where you shoot from, really hard to blend out fencing when editing your photos afterwards. And the biggest problem with plexiglass is scratches or glare on the windows. That’s a major issue I have when shooting. But when not hampered by those issues, you can get stunning shots with the animals being up close most of the times and possibly obscure elements of their environment that may not be “natural” such as fencing or poles that make up their exhibit. And as for islands, it’s your least obstructive exhibit style for shooting and the sunlight can proper illuminate your subject much better without the presence of bars or fencing. But your big drawback is focal length if you don’t have an impressive range to get the kind of candid photos like portraits and zoomed in full body photos.

Some examples of exhibits featuring each that I’ve shot and have worked for me well

1. Cages: Asian Leopards exhibit in San Diego Zoo

2. Plexiglass: Jaguar exhibit in Los Angeles Zoo

3. Islands: Kikuyu Colobus monkeys island from the San Diego Zoo Safari Park

 

Yes, there is always to some degree a risk of primates drowning in moats but that isn't the only risk.

Another thing I would add but one that is only really relevant to the situation here in Brazil (but that may be of interest) is that New world primates kept in zoos on islands surrounded by moats / ponds (these are bodies of stagnant water where Aedes aegypti and Aedes albopictus frequent and lay eggs / larvae develop) can be at risk of being infected by yellow fever during the seasonal period where mosquitos are abundant and transmission is more likely.

When these primates are kept in cages these can be covered in netting (it isn't a fail safe / perfect solution by any means though) to reduce the likelihood of the transmission / infection and improve the ease of administering veterinary care. This is just one of the many reasons that it is better to keep some Atlantic rainforest species of conservation concern that are highly susceptible to this disease such as the brown howler monkey, muriqui and the lion tamarins in cages rather than islands.

 

Islands are common in European zoos but fairly rare in American ones, because islands are difficult for the keeper to get to on a regular basis. As a photographer, islands are probably the best of these three types because they allow me to get clear shots. But for the animals, I think the cage is the clear winner. It just provides so many climbing opportunities!

 

I’ve seen islands where keepers had to install a plank every time to reach the exhibit, and also islands where keepers wear waders and walk through the moat.

 

Santa Barbara has a bridge accessible to keepers and monkeys allowing them to have the choice when they want to be on the island. (The Santa Barbara zoos gibbon island is a great example of why islands are so great for monkeys)

 

One of the biggest problems with island exhibits is space. It not only takes more space, but has MUCH less space avible to the animals.

 

When we say cages are we including netting because that makes a big difference in the conversation.

 

It's not plexiglass or an island, so I'd say yes.

I agree with birdsandbats' statement about cages being the winners. Cages may not always look the most natural, but they give animals more opportunities for enrichment than other exhibit designs might.

 

I think a combo of cages and glass are best to provide good climbing space and viewing areas. An example is the Langur exhibit at the Los Angles zoo.

 

Oh, I like that exhibit. It’s got nice landscaping and vertical depth for climbing, too. What I don’t like is if an exhibit like that had no viewing area besides mesh, which would make the animals hard to see.

Also cage bars and mesh tend to look like prison cells from a human perspective, so photos of animals in such exhibits could be co-opted by anti-captivity activists.

 

That's why the mesh-glass exhibit is so nice because it is open-air and the main viewing area cant be used to make the exhibit look like a prison

 

Islands are onlyan option for REALY big enclosures, were a cage/net is not feaseble. and the disadvantages (less space, and possibility of drowining are not realy a problem anymore

 

I wouldn't say islands are rare in American zoos, although I don't have any statistics to directly compare them to European zoos. Primate islands in particular are still a feature of many zoos in the US.

My opinion on this depends on the species, but in general for smaller animals I lean towards what @Westcoastperson suggested: a main base of mesh and glass viewing panel(s), so you get the functionality of both. I prefer this over islands for primates specifically since (as has been noted) moats take up an inordinate amount of space and can be a safety risk for non-swimming animals.

 

I have found that islands are more common on the east coast or eastern midwest than on the west coast I only have two examples of large zoos on the west coast with an island (Santa Barbra and SDZSF) whereas the east coast has quite a few (zoo Miami, Bronx Zoo, and Cinncinati zoo) This can most likely be attributed to lack of space and waterways (Santa Barbra is next to a lake and has the island in a cove, and SDZSF being huge and having enough space for a lake). Whereas on the east coast there is an ample amount of space and lakes, rivers, and marshes are common enough to give space for islands.

 

I think it's more common in lower quality AZA/roadside places. Wildlife Safari is a big zoo on the west coast with islands. Metro Richmond has several. Roer's Zoofari has one.

 

You may be right as while it's not a roadside zoo and does have excellent care Santa Barbra zoo it isn't the best out there

 

Of these I would prefer plexiglass.

However, what I really would want is one with grade separation. The path would be at a higher level than the exhibit so you could look down on the animals with no obstructions.

(An example is the high path over the North American River Otter and Beaver exhibits at the Smithsonian National Zoo).

 

I just realized we are talking about all animals, not just primates and great apes (don't know why I thought that) so I would have to say plexiglass is definitely the best for viewing opportunities, honestly cages just aren't great for animals like bears and antelope. They can't be in these small enclosed areas. That being said my second would be islands/moats as they are the most natural exhibits and can have lots of foliage, they also provide views of the entire exhibit that you can't always get with glass.
Also what about exhibits that have walls/pits and have viewing from above? while they aren't the most unique they still provide a natural and large exhibit. Emmet reminded me that these are also acceptable exhibits that provide good views, natural foliage, climbing space, are safe, and look nice and natural.