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Have you ever wondered if a Tiger and an Orangutan could share an enclosure? No? Well I bet you are wondering about it now. With animal rotation we can actually make this happen – in fact, someone already has!

Let me start by explaining what animal rotation is. Imagine a zoo exhibit set in a big circle with five enclosures each connected. Every day the animals move forward one enclosure until, a week later, they are back round to the beginning.

This idea was developed in the late 1980s and mid 1990s by the most famous zoo designer of our age, Jon Coe. His idea was that if different animals could ‘timeshare’ enclosures then this would mean animals have access to more space and different scents.

If you think this sounds like a normal mixed-species exhibit then you are missing one key thing. In animal rotation you can mix predator and prey. That’s right, you could have an enclosure with wolves one day and deer the next, never actually meeting but still crossing each-others scents.

What different types of animal rotation are possible?

Animal rotation can be simple or it can be devilishly difficult depending on how many animals and how many species you need to move.

The very simplest form of animal rotation is the one currently performed in most zoos around the world – day/night rotation. A large proportion of exhibits have night houses for the animals, maybe to provide extra heating or allow the vets to come in and get up close. This isn’t exciting or flashy so let’s move swiftly on…

The next type of rotation in terms of complexity is single species rotation. This is where we have multiple enclosures for a single species and we can control which they visit on any given day. This sounds simple but trying to manage the moving of different troops of gorillas is anything but simple! A really good example of this featured in my last blog post on animal enrichment. The Smithsonian National Zoo (of USA) has a series of different orangutan enclosures each connected by walkways in the sky. They can control which orangutans have access to which enclosures and so can make sure that new mums aren’t bothered by rowdy males.

Orangutans at the National Zoo riding the O-line – one of the best examples of single species rotation. Source: Wikimedia commons.

Now we get on to the exciting bit… mixed species rotation. This gets to the very core of what animal rotation is about. Here we have different species being moved between a range of different enclosures and so coming into contact with the scents of other animals. This is what most of this article is going to be about so I’ll fill in the details below.

The holy grail of animal rotation would be semi-compatible mixed species slow rotation. Quite a mouthful.  The idea is that you would be able to have animals interact as a rotation was happening (hence the slow). Not only that but, providing you were good at your transitions, you could do this with animals that aren’t compatible in normal enclosures. Here you might transition your rhinos through your buffalo exhibit. In the long term this would lead to issues but for short bursts of time would allow us to observe interesting behaviours in the buffalo.

Imagine seeing this in a zoo! Photo by Frans Van Heerden from Pexels

So how do you do animal rotation?

The first thing to say is that this stuff isn’t easy. You can’t just adapt what you have and hope it will work. You really need to build this into the enclosures from the very start.

Let’s talk about the nuts and bolts of animal rotation… literally. To make this work well you need to have a system of gates and pulleys working in the background which can ensure the wrong animals don’t mix. You really don’t want the predator to meet the prey! These gates will open onto transfer passages (typically strong steel) which have to be built for the biggest animal in the whole rotation.

This is an example of the workings behind the Louisville exhibit. Picture from https://louisvillezoo.org/rotational-exhibits/

You wouldn’t really have a simple circle of exhibits, you’d have lots more connections between all exhibits, or a central room so you could move any animal from one exhibit to another without having to move the intervening animals. The paths between exhibits might need to be a different levels for different types of animals – your orangutans might prefer transferring at a higher level than your tapir.

Once you have the mechanics sorted you need some cooperative animals. It isn’t going to be practical just to open a door and wait 5 hours for a tiger to walk through it. You need the transitions to be quick and controlled. This is where operant conditioning comes in. Operant conditioning is a posh way of saying the animals are trained to go through the walkways by always receiving a reward for doing so. It might be slow at the start but it will eventually get to the point where the sound of the gate moving will prompt the animal to be up and through the passage like a shot.

In order to make all this work you will need a team of committed, expert keepers. Not only do they need to work on the operant conditioning of the animals, but they also need to actually do the transitions. This is likely to involve daily meetings to plan out the schedule of rotations, working in teams to operate the pulleys and levers, and keeping tabs on which rotations work best.

This trio of a ground-up enclosure design, well behaving animals and a committed team of keepers is not going to be as easy as a typical single species traditional exhibit so why would you do it?

8 reasons why zoos should do animal rotation

I’ve alluded to a number of different benefits which this could bring above but I wanted to dig into each of these a bit more. I can think of at least 8 however if you think of anymore I’d be keen to hear them in the comments.

Animal Enrichment

The main reason Jon Coe came up with this idea in the first place was as a form of animal enrichment. There are five different types of animal enrichment and animal rotation is the key to unlocking the most difficult – sensory enrichment. This is the type which includes stimulating an animal’s sense of smell.

By having animals move enclosures regularly you are providing a mechanism by which they can come into contact with the scents and pheromones of other animals. This is at its most engaging when a predator species moves into the enclosure where is prey has been. In Louisville Zoo this is where the Tiger is moved into the exhibit of a Tapir and if you are there at the right time you can see the tiger following where the tapir has been.

Imagine watching a tiger tracking a tapir that had been in the exhibit just hours before! Photo by capri23auto from Pexels

It doesn’t have to be predator and prey though, it can also be very powerful with multiple troops of the same species setting out territories. In a typical zoo exhibit, territories are marked out and then they stay relatively fixed. In single species animal rotation you are moving troops into new territories on a daily basis. The animals in question then have the opportunity to display territory marking behaviours they otherwise wouldn’t need to show.

Healing Enclosures

When you have a big animal they can often be quite disruptive to the enclosure they are in. Have you ever wondered why indoor ape houses are relatively barren and have everything fixed to the ceiling, walls or floors? Apes break things, throw things, snap things, and all round cause havoc. Or if you have a rhino regularly walking a route in an outdoor enclosure it will quickly wear away the grass. Different animals have different usage patters and different levels of destructive ability so by rotating them around, you give the enclosure time to heal.

If you want to be a bit more specific you can group your animals into three categories (1) highly destructive, (2) niche destructive and (3) not destructive. You can then design an rotation which allows you to go 1,3,2,3,… or something similar. This way the enclosures last much longer without needing refurbishment. This is important for zoos who recognise refurbishment means animals off view, money being spent and potentially visitors being disappointed.

Cleaning Opportunities

In a typical zoo exhibit cleaning can be a bit of a pain. You really have two options, either you have small houses to put the animals into while keepers enter the exhibit (tigers, lions, bears, monkeys, rhinos,…) or you allow keepers in the exhibit at the same time as the animal (reptiles, birds, some hoofstock, meerkats,…). In both cases there is a pressure to be really quick.

To make animal rotation work you need to have one more empty space than you have animals to display. Because you can move animals around you can choose which exhibit is going to be the empty one for the day without having to take all the animals off view. This is particularly useful if you have a star animal like a leopard or tiger. They can still be on display to the public while you can get in the enclosure they have just left and give it a good scrub.

Knowing that you don’t have to rush to get the animals back on show, or that you don’t have to watch your back for stampeding zebra, you can take more time and do a more thorough clean than might otherwise have been possible.

Larger spaces for the animals

A fundamental premise of animal rotation is that in the wild animals have large territories but only spend time in a small portion of that territory on a daily basis. By rotating animals it is like you are allowing them to have 5 times more space in their territory knowing they wouldn’t be using it all every day anyway. It’s kind of like Airbnb for animals. When one animal takes a trip out to its second (or third or fourth) home there isn’t any reason why another animal can’t use the space. That way everyone gets a holiday!

Training time

As we’ve talked about above, one of the key requirements of being able to make animal rotation work is having well trained animals. If you ask any zookeeper about which bits of the jobs they’d like to do more of then I’m pretty sure they wouldn’t say the paperwork and the cleaning. It is a reality of being a zookeeper that you are stretched quite thinly having to do a myriad of jobs across a range of enclosures. If a zoo is going to be serious about animal rotation then it forces zoo management to put training much higher up the zookeepers agenda, hopefully giving more time to the keepers to do the things they love.

Yes. That’s right. You can use this kind of training for polar bears!

Off-exhibit time

Another benefit of having an interconnected set of enclosures with animals that are trained to move between them is that it is easier to take an animal off-exhibit. If you were designing an animal rotation it would make sense to have a couple of non-public facing rooms to relieve some of the pressure of the animals. One thing you might not realise is how much noise the public make – a break away might be very pleasant every now and again.

In most animal exhibits there is the facility for the animals to get away from the visitors but it is definitely easier in an animal rotation system. Maybe you notice a rhino behaving a little out of the ordinary, in animal rotation you can get him straight into an off-exhibit enclosure without having to even break a sweat. Better for the rhino and better for the keepers.

More wild feel for visitors

One of the cool things that visitors report about animal rotation is that it feels more like animal spotting in the wild. In any given day the public won’t know which animal they are supposed to be seeing until they see it. In addition, for regular visitors they get the chance to see the same animal in different exhibits which makes for a more interesting return visit.

More interesting for keepers

When animal rotation works well it empowers the keepers to make decisions about which animals are on display in which exhibits. It also encourages a stronger collaboration between keepers of the various animals involved rather than have them focused only on their areas of expertise. By encouraging more team work and giving more responsibility to the keepers you can create stronger teams and better morale in general. They say the best ideas come from collaboration so having keepers of 5 types of animal meet on a daily basis to discuss their needs can’t be a bad thing right?!

5 reasons why zoos don’t do animal rotation

If animal rotation is so great why isn’t everyone doing it. I think there are at least 5 reasons which mean someone might want to think twice…

It is pretty expensive

Very few zoos have the money to build a number of large exhibits from the ground up instead favouring a more gradual improvement. This doesn’t work for animal rotation as everything needs to be built at the same time. In the UK this limits any kind of project to only a handful of zoos and with the pandemic hitting finances so hard I wouldn’t expect to be seeing this any time soon.

The next reason animal rotations are expensive is that you have to build every enclosure to be strong enough to contain the most destructive animal. Whereas you might be able to have a low wooden fence for a tapir on its own, if a tiger is going to be using the exhibit the next day you’re going to need more than a bit of wood. This is probably the biggest reason why a zoo might choose not to go down this route. The choice a zoo financial director will need to make is does he get more revenue from 5 animals using animal rotation or from 6 animals without.

Requires more staff

Then, on top of the build costs you have higher staff costs. To do animal rotation well you are going to have to have a few more staff about the place. The increase in time spend on training, planning and actually moving the animals will need to come from someone and keepers are likely to be stretched already. The only real option you have is to hire in more people – good for zookeepers but bat for finances.

Now some of these cost factors can be offset by needing smaller space for the number of animals. In somewhere like London Zoo you simply wouldn’t have the space to build 6 full enclosures anyway so going for 5 in a space saving way might work out much better. You could also have a less themed off-exhibit space cutting a bit of cost there but at the end of the day, cutting edge zoo design is going to cost money.

Dead space

Dead space is a zoo directors worst enemy. Animal rotation needs at least one of the exhibits to be empty at any given time so that the rotations can all happen smoothly, so that enclosures can heal and so that a thorough clean can be done. The problem is that visitors really don’t like dead space and, if you are a zoo director, you want to be getting as much bang for you buck in terms of visitor experience as possible.

To make this work you need to have a very well designed exhibit which means the visitors almost see past any dead space. Maybe by having multiple off-exhibit areas perhaps?

Things can go wrong

It is undeniable that the more complicated you make something the higher the chance that something goes wrong. I’m no expert in accidents at zoos but I’m pretty sure the risks involved in this kind of exhibit are going to be at least a little higher than in your standard single species exhibit. If you get your animal order wrong then you might end up with a tiger chasing a tapir and that s absolutely the last thing you want to have plastered all over the local newspapers!

Higher risk of disease transmission

When you have multiple animals sharing the same space they are going to come into contact with each other’s urine, faeces and saliva. This is really the point of animal rotation so it shouldn’t be a surprise. It does however increase the risk of disease passing through different animals. These risks are already faced by zoos that have static mixed-species exhibits but the diversity of animals you can rotate might mean there are transmission possibilities which haven’t yet been considered. We know humans can give coronavirus to tigers, and we can’t give it to dogs, but can a tiger give coronavirus to a wolf? Animal to animal transmission varies by species and its not the thing you want to try with your collection of rare and endangered animals.

Would animal rotation work for you?

It is clear there are pros and cons so in what situation does animal rotation make sense? If you are a leading city zoo without a lot of space but a decent bank balance then I think this is the way to go. It would be world leading, it would allow more animals in a smaller space and it would be good for the higher numbers of return visitors you have due to being in a city.

When wouldn’t you do this? I would say if you are a wildlife park out in the country with more land than you can shake a stick at then just build another enclosure or two with the money. Your average zoo visitor driving out of their way to come to your zoo will do it because of the animals you have, not necessarily because you are at the cutting edge of enclosure design.

Which zoos currently do animal rotation?

I thought I’d finish off by giving some examples of zoos that actually employ animal rotation in a meaningful way. With one exception these are all stateside. It is a general rule that the USA is about 10-20 years ahead of Europe when it comes to trying new zoo design techniques. Maybe it’s the much larger numbers of wealthy benefactors who like to see their name at the front of an exhibit.

Louisville Zoo

By far the most famous example of animal rotation happens at Louisville Zoo. This is where Jon Coe designed the first animal rotation exhibit in the world. It’s also where most of the research on how it improves animal enrichment has been done.

The exhibit in question is called ‘Islands’ and features a mix of Tiger, Orangutan, Tapir, Babirusa and Siamang. The way they split up the exhibit is to have three naturalistic outdoor enclosures, one indoor ‘day room’ and a number of smaller off display areas. You can see in the picture below that it might not be your traditional circle but there are shoots and passages leading for every enclosure.

This image is from the Jon Coe paper on animal rotation and shows the set up at Louisville Islands Exhibit.

The fabulous YouTube channel Zoo Tours have actually filmed a visit to the Islands so you can see it for yourself. I’ve copied the video in below so if you have 10 mins spare then get a cup of tea, kick back and enjoy.

Zoo Tours have lots of great videos – check them out!

Louisville also has multiple troops of gorillas and so they do a single species animal rotation across all their gorillas. Can you tell Louisville like the animal rotation idea?

Denver Zoo

Denver zoo started their forays into animal rotation by letting the hyenas into the lion exhibit after the lions had gone to bed. This was clearly successful as they’ve now implemented animal rotation for the hyenas and the wild dogs. Okay, this might not be 5 species like at Louisville but it’s a start!

Atlanta Zoo

Atlanta zoo had a program of moving gorilla troops between exhibits. There was some good science done over a five year project to show this was beneficial to the animals but for some reason they’ve now stopped. My guess is that they couldn’t afford the extra staff to make it work but that is very much a guess!

Toledo Zoo

Toledo zoo uses animal rotation in its primate forest section where it cycles a 6 monkey species across three public facing displays and three off-exhibit enclosures. This is the example with the largest number of animals off display at anyone time.

California Science Centre

For those that don’t know, Californian Science Centre has a reputation of holding a world leading mix of all sorts of species. It makes sense then that a place like this would try and be at the cutting edge of zoo enclosure research. They run a multi-species animal rotation. In the Asian Rainforests section of the zoo there are three rotating enclosures which at any time may hold hornbills, kites, babirusa, small-clawed otters, fishing cat, binturong and siamang. Part of the excitement is that it allows multiple mixed species exhibits to be tried on a short term basis, hopefully giving other zoos good evidence for compatibility in future exhibits.

Point Defiance Zoo

Another Asian exhibit where tigers, tapirs, siamangs, porcupines, otters, anoa and gibbons can be rotated around 5 enclosures. This came after the Louisville example and has clearly taken a lot of the learning from them which you can see in the choice of species.

Zurich Zoo

The only European Zoo on this list (please mention in the comments if you know of others!). Zurich zoo doesn’t run the typical animal rotation program but it gets a special mention because it lets the wolves run loose in the tiger enclosure if the tigers are in bed. Here is a video of the wolves sniffing all around the tiger enclosure, clearly demonstrating the stimulation that comes from animal rotation

Final thoughts…

Zoo rotation might not be for everyone due to the cost but, providing you can stomach the hit, it does bring a whole new type of enrichment and stimulations into the animals lives. It isn’t only the animals though, animal rotation can benefit both the guests and the keepers so if you just happen to be spending £20m on a new zoo enclosure why not give it a thought?

P.s. if you’ve scrolled all the way to the bottom to find out if a tiger and an orangutan can share an enclosure the answer is yes, but not at the same time. Please don’t put your orangutans in with your tigers.

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