To what extent is pacing an indicator of stress in carnivorans?

Something that anti-zoo people seem to bring up a lot as a reason why zoos are bad is stereotypic, stress-driven behavior. "Zoochosis", if you want to use their lingo. A well known example of this is pacing in carnviorans, like felids, ursids, canids, etc. As much as it hurts me, a longtime zoo lover, to admit this, since reading about this as of late, I have been more attuned to said behavior, and have witnessed several instances of it on my recent zoo visits. For example, big cat enclosures, even expansive ones, often have trails indicating frequently-used routes along the edges of exhibits. For example, when I was at Detroit the other day, an Amur tiger walked back and fourth along its enclosure's back fence a couple times. And in a video I recently saw from the Philadelphia Zoo, a sloth bear kept going back and fourth along the edge of its enclosure. I could probably easily name a half dozen more instances I've witnessed in the recent past. Does this mean that even in standard AZA zoos, where animal welfare is of the upmost concern to staff, the pacing animals like tigers and sloth bears still seem to do a lot of indicates they are dealing with considerable stress regardless? Should I pushing much more aggressively than I am for phasing these animals out of traditional zoos, into facilities more like The Wilds or White Oak Conservation? Or have I been brainwashed by anti-zoo people and do most examples I've likely witnessed of carnivorans pacing not likely represent stressed-out animals? Not to sound too aggressive, but these questions have been eating me a little bit lately and I'd like some answers from people I trust aren't too biased either way.

 

In many carnivorans, especially bears and big cats, pacing is not an indication of stress at all, but rather a territorial display.

 

Yes, it’s important to differentiate between an animal walking back and forth for one reason or another (there’s only so many places it can walk in an enclosure), anticipatory pacing, and pacing because it’s mentally stuck and feels compelled to perform a repetitive behavior and has difficulty breaking the pattern

 

Many animals with keen senses of hearing and/or smell will pace in anticipation if they realize a keeper is coming, if it is close to a meal time, or if there is an animal next door that has their interest. If they can see the object of their interest that often heightens the pacing. For example I once saw a snow leopard running back and forth on a certain ledge high up. From up there he could see the Aardvark moving around in the next exhibit and was hunting it rather excitedly, rather than pacing in stress. I've also seen many different species excitedly pacing in front of their shift doors or where they can see the keeper path when they know food is coming.

 

Pacing is seldom an indicator of stress in carnivores. It can be, but there are three more likely reasons for pacing:

1. Territorial Pacing- it's common in the wild for territorial carnivores to patrol the boundaries of their territory repetitively. In zoos, this translates to the bear or big cat patrolling the boundary of their exhibit.

2. Pacing in response to a stimuli- the animals may see, hear, or smell a keeper in the back area behind their exhibit, or may smell something that looks like food, or possibly another animal nearby. You'll see this in basically any Zoo, and is also similar to what would be seen in the wild when a big cat sees, hears, or smells something.

3. Pacing as a result of development- animals oftentimes develop patterns early in life, and it's difficult for them to break these habits later in life. This can be seen if an animal may have been in a stressful, pacing-inducing habitat prior in their lifespan, even if their current home is better. Furthermore with bears and cougars, many of the bears in zoos are rescues- meaning they may have some sort of trauma from earlier in life that may show itself in pacing or other stereotypies.

While pacing can indicate stress, its more likely indicative of one of these three things listed above.

 

Thank you for all the responses. I’m assuming it’s still normal if the pace is over a relatively small part along the edge of a larger exhibit? An example of this I recently saw was a several going back and fourth a few paces repeatedly at Milwaukee, along the glass.

 

Yup, perfectly normal.

 

Regular pacing or unnatural repetitive movements is result of long-term deep deprivation of the animal´s basic physiological needs. It will be activated or aggravated at moments of anticipation, stress or other stimulus.

It persists even after the animal is moved into better enclosure. The same way an animal that grows with severe malnutrition will forever live with deformed sceleton, even if it later gets sufficient care.

 

I met with several different opinions. Stereotypy is a sign of stress. However, carnivores regularly use certain paths, so following set path on an exhibit, without a sign of mechanical repetition, is not necessary bad. One zoo director even suggested that completely happy wolves would still spend a considerable time running around their exhibit, much like a domestic dog on a walkie.

 

I'm simply trying to indicate that it is not a sign of abuse as evilmonkey239 outlined in his original post, I obviously don't know the whole situation but I am familiar with the zoo and enclosure in question and have actually seen the mentioned behavior there.

 

I do not know. But it is not unusual for healthy and normal cats to pace, so the mere fact that the behavior was happening is not at all a cause for concern. I do not know all of the details but nothing stands out as unusual or cause for concern here.

 

I've never been to this specific zoo, and don't have any specifics to provide, however what I will say is that the behavior depicted is *usually* perfectly normal, and servals are one of the species I've seen pacing most frequently- both as an anticipatory action (e.g. pacing near the back when the cat hears a keeper) and as a territorial action, pacing repetitively as a means of guarding their "territory" (exhibit). Yes, there is a chance this behavior was stress-based and something of concern, however I would argue, given what I know about behaviors of this kind, that the burden of proof lies on proving it *is* stress-based, not proving that it is not stress-based. So without any inside knowledge into this specific cat, I'd agree with @birdsandbats comment that this is perfectly normal, however it is important to acknowledge there is a chance that this behavior is stress-based, even though this is not the most likely reasoning.

 

By the way, if somebody deals with a specific animal pacing, it is often possible to see what animal is facing and what it is facing away during pacing.

In bears, pacing is very often motivated by a desire to get away from a dominant animal. It is often as visible as two toy magnets pushing away each other. One bear goes left, another immediately gets up and goes right. The first bear goes right, the other bear immediately goes left etc etc... Luckily, zoos in the recent decade largely stopped keeping groups of bears in small exhibits.

 

I remember reading a study on anticipatory pacing due to opening the gates for behind the scenes areas/feeding. I’ll try and find that study again.

I don’t know much about this topic overall but something important to consider would be individual animals’ personalities and their arrangements with other animals.

 

Unfortunately I do not have the time right know to go over all the publications, but as someone with at least a bit of background knowledge regarding pacing in felines, here's a few facts.

Pacing is considered a form of abnormal repetitive behaviour (sometimes called stereotypical behaviour, thought the former is generally broader in scope), which is often seen as best avoided in any situation. It is a highly complex behaviour with a large set of influencing factors, ranging from enclosure size to feeding schedule to even such things as the attitude of the zookeepers.

Few studies in large felines have in depth analysed the direct correlation between stress and pacing, but I am aware of at least one publication on clouded leopards which showed a link between increased pacing and increased cortisol levels. The reason such things are not more widely studied is because frankly more fundamental studies are an afterthought in most zoos. Most zoos focus their research on things they can improve in smaller time scales, instead of understanding things like pacing on a more fundamental level to be able to tackle it more thoroughly in the further future (though I must say there is improvement in several zoos!).

There is evidence that territorial behaviour does play a role in pacing, mostly because species with larger natural territories pace more than those with smaller territories. But I have never seen it regarded as the single explanation. One problem is that territorial patrolling in circles through the exhibit can sometimes be difficult to reliably differentiate from more problematic pacing, such as continually walking back and forth over the same path.

In short: pacing in carnivores is a complex phenomenon in which stress is almost certainly one factor at play, but not the whole story. Simple statements ("it is all good" or "it is all bad") are almost always wrong.