#227      24 min 16 sec
Contentedly caged? Researching the behavior of animals in captivity

Doctoral students Sally Sherwen and Megan Verdon describe their investigations of animal behaviour in enclosures, from animals on display at the zoo, to pigs being bred for food. Presented by Dr Dyani Lewis.

"When we house the sows in commercial groups, we are often mixing unfamiliar sows together; they don’t know each other; they didn’t grow up together; they have limited space and they have limited resources such as food; some of their welfare is quite severely compromised as a result of that high aggression." -- Megan Verdon




Sally Sherwen
Sally Sherwen

Sally is a PhD student with the Animal Welfare Science Centre and Zoos Victoria.  She has always had a passion for wildlife and completed her undergraduate degree at The University of Melbourne with a double major in conservation biology and marine biology. She then went on to a master of science in zoology and studied a wild population of black swans for two years investigating their incubation behaviour. She is now mid-way through her PhD researching the effect of visitors on animal behaviour and welfare in Australian zoos, supervised by Prof Paul Hemsworth (AWSC), Dr Michael Magrath (Zoos Victoria) and Prof Clive Phillips (University of Queensland). As part of her PhD, Sally studies a range of animals from meerkats to capuchins, shedding light on their interactions with visitors and how it can influence their behaviour and welfare in zoos. Understanding these visitor effects may provide opportunities to improve animal welfare, and in turn enhance the support for zoos and their role in education and species conservation.

Megan Verdon
Megan Verdon

Megan Verdon is a PhD candidate conducting research into sow welfare with the Animal Welfare Science Centre. After completing a Bachelor of Science majoring in Chemistry and History and Philosophy of Science, Megan worked as an R&D chemist at a paint manufacturing company. However, her love of animals drew her back into study. She completed a Postgraduate Diploma in Animal Science and Management at the University of Melbourne through the Animal Welfare Science Centre in 2010. Megan started working with animals when she was 14 and still works at an animal shelter and with seeing eye dogs. She commenced her PhD in 2010 with the Animal Welfare Science Centre looking at how individual sows vary in intro-specific aggressiveness (aggression delivered and aggression received), and if this variation is related differences in welfare (in terms of cortisol, injuries and productivity) when housed in commercial groups. She is also whether aggression in sows can be predicted, and how the distribution of aggressive sows in a group affects the welfare of the individual as well as the group as a whole. Megan’s work on sow aggression, welfare and group dynamics aims to assist pork farmers in optimising group housing for sows and improving sow welfare throughout gestation.

Credits

Host: Dr Dyani Lewis
Producers: Eric van Bemmel, Kelvin Param
Associate Producer: Dr Dyani Lewis
Audio Engineer: Gavin Nebauer
Voiceover: Nerissa Hannink
Series Creators: Kelvin Param & Eric van Bemmel

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VOICEOVER 
Welcome to Up Close, the research talk show from the University of Melbourne, Australia. 

DYANI LEWIS 
I’m Dyani Lewis.  Thanks for joining us.  Human beings have a long history of living in proximity to other animals.  We have domesticated cats and dogs to be our companions; horses to ease the burden of our work and numerous other species to be eaten at our dinner table.Beyond domestication our fascination with animals has seen millions of animals globally placed in zoos, aquariums and wildlife sanctuaries, mostly to satisfy our curiosity, but increasingly for captive breeding programs to bolster wild populations in decline.Keeping animals captive, for whatever purposes, requires that animals feel secure and content, but how do animal keepers ensure the welfare of their charges, whether on the farm or in the zoo and what are we still learning about animals and how they behave and cope in captive settings?Joining us today on Up Close for our annual PhD episode are two young researchers who are exploring animal behaviour and welfare as part of their doctoral studies at the Animal Welfare Science Centre, a joint centre of the University of Melbourne, Ohio State University and the Victorian Department of Primary Industries.Later in the program we will be talking to Megan Verdon about understanding the behaviour of domesticated pigs kept in enclosures. But first we are joined by Sally Sherwen.  Sally is looking at the behaviour of a variety of zoo animals for her dissertation, and in particular how they respond to zoo visitors.Welcome to Up Close Sally.

SALLY SHERWEN
Thank you.

DYANI LEWIS 
Now Sally when we think about zoo animals and their interactions with people we would often think about them interacting with keepers, but you are studying animals responses to visitors.  Has this kind of study been done before?

SALLY SHERWEN
It’s a relatively new area of research for zoos.  Most of the zoo research to date has really focused on things like enrichment programs and how that benefits the animals, or captive breeding programs and how to get animals to be more reproductively productive, with really little attention being given to human animal relationships in zoos, which is quite surprising because it’s actually a really well established area of research in the agricultural setting and the same types of models can be applied to animals in zoos.Obviously in zoos there are several types of humans that can interact with animals.  The two main categories are keepers and zoo visitors.  Keeper interaction I am not focusing on, but there has been a little bit of work done on that, overseas particularly, but the visitor side of things is what I focus on because it’s a condition that the animals are constantly exposed to and it has the potential to be certainly enriching if it’s a constantly changing part of the zoo animals environment, as well as potentially stressful if close proximity to humans is a source of stress for the animals.So research on the visitor effect in zoo animals is, as I said, relatively new, but there have been a few studies that have been done - particularly in the US and the UK, not so much in Australia. There are still significant gaps in our knowledge in the area because much of the work to date it faces lots of methodological challenges in the field - things like replication and confounding variables of working with different zoos.For example lots of the studies have been looking at natural fluctuation in visitor numbers - so busy days and quiet days - and then they look at the animal behaviour in response to that, so more of a correlation type study.The problem with those studies is that the high visitor days and low visitor days are likely to coincide with things like weather conditions. So it might be a rainy day and there are low visitor numbers, and of course this is going to influence the animal behaviour as well.

DYANI LEWIS 
Explain to me what your study is and how it gets around some of these problems.

SALLY SHERWEN
Well basically rather than trying to deal with the natural variation in visitor numbers, which is confounded by things like weather conditions and season and holidays and other bits and pieces that can influence animal behaviour as well, I try and focus on using experiments to test the different effects of visitors on animal behaviour and welfare.

DYANI LEWIS 
So give us an example. Like what species are you working on and what would be the experimental set up?

SALLY SHERWEN
So for example meerkats are the species I started working with, just because there are huge numbers of them in Australia.  Meerkats - they’re a small carnivore part of the mongoose family that live in the southern parts of Africa in the dessert and live in big family groups and there is actually a popular TV show called Meerkat Manor that follow a group in the desserts of southern Africa.Australian zoos work with meerkats really easily.  There’s good numbers and similarly designed enclosures, so I had several sites readily available of meerkats to study.  For those guys I was really interested in intensity of visitor behaviour and how that influenced their response.  Being such a small little carnivore I was interested in what intense visitor behaviours like sudden movements, shouting, loud noises, things like that - how those type of behaviours influenced the little meerkats’ response.So I set out to manipulate that and I did that by having at each enclosure several uniformed people and signs up asking the visitors to passively watch the meerkats and not make any noise and then I had uncontrolled days where people were free to do whatever they want.

DYANI LEWIS
So in general the public are fairly disruptive unless you have someone in there to stop them?

SALLY SHERWEN
In general the meerkats are a species in the zoo that the public really enjoy interacting with, in that there is usually only a piece of glass that separates humans and meerkats.  It’s quite common for people to bang on the glass, run up and down, throw things over; they’re a very popular zoo animal and kids particularly get really excited by all their activity and running around.So the potential with those exhibits is to be, like really high intensity of visitor behaviour which can obviously impact their behaviour and welfare.

DYANI LEWIS 
So how did the meerkats respond?

SALLY SHERWEN
Well at all sites there was no significant difference in meerkat posture, behaviour, position, vigilance, any type of behavioural indicator that they would be avoiding humans.But on the other hand the experiment in itself where the noise level was significantly reduced with the treatments, the visitor behaviour was significantly reduced, so we did create a significant difference in visitor conditions for them in that we had very passive crowds and quiet noises on some days and then very high interactivity on other days with the people.The meerkats still didn’t adjust their behaviour at all, which is not all that surprising with meerkats because they do tend to do, as I said before, really well in captivity.  They breed well. They eat well.  They’re very active.

DYANI LEWIS 
You’ve mentioned breeding a couple of times; I guess that would be a clear indicator if an animal is not happy, if it’s not breeding well, is that right?

SALLY SHERWEN
Yes, the physiological mechanism of stress can influence an animal’s hormones which means that it can disrupt their breeding and their health and their longevity.  Things like that are really good indicators that something is not quite right with their welfare.

DYANI LEWIS 
So you have looked at meerkats and they seem to do quite well. What are some of the other species that you have looked at and do they do equally as well?

SALLY SHERWEN
Other species that I have looked at are kangaroos in free range exhibits.  So here in Australia there are lots of - they’re called free range or walk through exhibits where people can walk through on designated paths and the animals have the option of coming across the path or going into their quiet zone.  So there is like a physical barrier there.  So the potential for interaction is really quite high as well.So I have looked at the effect of these types of high intense kind of interactions with sudden movements, loud noises, overall noise level of crowd and overall number of visitors; looking at the effect of that on kangaroos in particular in several walk through exhibits.  My data is still being analysed, but the preliminary look at it shows that the kangaroos are further away on busy type conditions, rowdy type crowds - further away from the visitor path - and also more vigilant, which is suggestive of avoidance behaviour.  But I haven’t analysed faecal samples yet which will give me a nice measure of the physiological side of things.

DYANI LEWIS 
So what are you measuring in the faecal samples?

SALLY SHERWEN
The faecal samples is a good way in zoo animals; it’s a very non-invasive way of sampling glucocorticoids.

DYANI LEWIS
Glucocorticoids - are they a substance that is commonly used to measure stress in animals?

SALLY SHERWEN
Yes, a nice way to get a physiological indicator of how an animal is doing in terms of its welfare is by measuring cortisol levels - which is a stress hormone - which can be picked up in a range of different things like saliva, blood, faeces, urine, and lots of the agricultural research actually samples for blood and that’s a really good indicator of how stressful a particular event is.But in zoo animals when you are more interested in an average kind of level of stress hormone over say a 24 hour period, faeces is a nice way to do it because it gives you rather than an event, an average level over a period of time in which the animals have experienced a particular condition.  So say busy, stressful, school holiday periods versus quiet, low visitor numbers, passive visitor behaviour; things like that.  So it’s a nice way that you can measure physiologically stress as well, coupled with behavioural observations.

DYANI LEWIS
So presumably some of this information you would ideally like to be fed back into management practices, so how does knowing when an animal is distressed help to control the management of zoo animals?

SALLY SHERWEN
With the visitor effect there is evidence that I can be either enriching or it can be negative or it can be no response at all to the animal.  So the animals can perceive visitors as just a regular part of their environment and it has no effect on their behaviour or welfare.So depending in what effect visitors have on the animal, that’s going to then depend on the management outcome for that.So for example, if orang-utans say are relatively stimulated by the constant variation of the visitor crowds moving through, then that may be an opportunity to enhance that interaction with the visitors which would be a form of enrichment for the animals.So some zoos have actually introduced different puzzle games that visitors can do with orang-utans through the glass barriers and things like that, and look at the interaction as a form of enrichment with the humans.Other animals that may show avoidance of the visitors or may be more stressed by visitors; it’s a matter of simple changes to the enclosure structure and design.  So potentially one-way vision or adjusting the height of the visitors, so the visitors may be lower looking up at the animals to make them feel more secure; and if it’s just more of an inanimate part of the environment then obviously no changes need to be done.The most important thing is to firstly understand the visitor effect in the species and then decisions can be made.

DYANI LEWIS
Are there some species that will never be happy in zoos no matter how much you change the style of their enclosure?

SALLY SHERWEN
That’s a tricky question.  Obviously species in zoos are selected really carefully and it depends on a lot of things.  So enclosure design as well as nutrition and basically zoos have to meet all the requirements of the species for its survival. Some zoos have tried and failed at certain species and some of these have done really well, but others - for example proboscis monkeys, big nose monkeys found in Borneo - they are notoriously difficult to keep in captivity and that reason is mainly because of the nutritional requirements are so hard to meet because the variety of plants they eat in the Borneo rainforests.I think only maybe Singapore Zoo and maybe one in Canada as well have successfully kept proboscis monkeys in zoos.But as I said before, meerkats on the other hand are a species that tend to do pretty well in zoos - breed well, highly active, lack of stereotypical behaviour, things like that.  So as to what it is exactly about a species that makes it do well in a zoo or not well in a zoo, there are so many different factors - and proximity to humans is one of the many factors that need to be considered.

DYANI LEWIS 
Sally thanks for telling us about your research.

SALLY SHERWEN
Thanks for having me.

DYANI LEWIS 
Sally Sherwen is a PhD student at the Animal Welfare Science Centre here at the University of Melbourne.You’re listening to Up Close. I’m Dyani Lewis.Our second guest on Up Close today is Megan Verdon, also from the Animal Welfare Science Centre. Megan is doing her doctoral studies on animal domesticated thousands of years ago - the humble pig. While some pigs are kept as pets and others as workers to sniff out truffles; the vast majority are raised for human consumption and our voracious appetite for pork has seen pig farming become more intensive to meet the growing demand.Pig welfare under these circumstances is even more important, and this is what Megan is here to speak to us about.Welcome to Up Close Megan.

MEGAN VERDON
Thanks Dyani.  Happy to be here.

DYANI LEWIS
Now Megan there has been quite a lot of consumer interest in improving the wellbeing of pigs in intensive farms. What practices in particular are unpopular with animal welfare advocates?

MEGAN VERDON
Well in regards to gestating sows - so the sows are the mother pigs who give birth to the piglets which we then fatten up and slaughter for consumption.  Most of it is to do with how they’re housed.  Often in intensive systems these growing sows are housed in what we call a gestation crate, which is pretty much a metal cage that individually house the sow and it prevents her from interacting with other sows, but is also is so small she can’t turn around and she can’t really walk.  She can take a step forward or a step backwards.So this sort of confinement housing seems to strike a chord with animal welfare activists.

DYANI LEWIS
How long are the sows in this sow crate for?

MEGAN VERDON
They’re impregnated by artificial insemination in the crates and they will remain in there for their 16 week pregnancy after which they’re then moved to what we call a farrowing crate, which is a similar system but it has a creep space underneath and that allows the piglets to be drawn away from the mother and means that they won’t get squashed from her.  So they go from crate to crate basically their whole lives.

DYANI LEWIS
So this system that’s used, is that common all around the world?

MEGAN VERDON
It is a fairly common system all over the world, but we are also seeing it beginning to be phased out.  Already in Europe it will be banned by 2013. When we say banned usually it involves a period that they’re still in stalls.  So in the EU it’s for four weeks until they confirm pregnancy. In the UK it’s been banned since 1999.  In New Zealand it will be banned for that post four weeks pregnancy confirmation by 2015.  IN the USA it is still a bit controversial although they are going by State by State legislating against it.  Currently there are approximately nine States, but the largest pork producers in the world - called Smithfield, from the USA - and Smithfield have committed to phasing stall housing before pregnancy confirmation by 2017.  Here in Australia we have got quite a unique system in that our pork producers have voluntarily agreed to phase out the housing of sows in stalls by 2017.

DYANI LEWIS
What are the alternatives to sow stalls?

MEGAN VERDON
For intensive systems the alternative is housing them in groups; putting them all into large groups ranging from 10 to 100 animals.

DYANI LEWIS
And when we put a whole lot of pigs in together like that how well does this replicate what we might know about social structure of pig groups in the wild?

MEGAN VERDON
Well this is the problem that we’re finding with group housing.  In the wild sows live in really small groups of maybe two to four females; they’re related; and they live with their piglets and they have all this space, they have all these resources.  So we see not much aggression between these animals who are familiar with each other, unless they encounter an unfamiliar group; then they might fight; or an unfamiliar sow.In contrast, when we house the sows in commercial groups, we are often mixing unfamiliar sows together; they don’t know each other; they didn’t grow up together; they have limited space and they have limited resources such as food; some of their welfare is quite severely compromised as a result of that high aggression.

DYANI LEWIS
So when you say aggression, what kind of things do they do?  Do they attack each other?

MEGAN VERDON
The nature of the aggression does change with time.  so when we first mix them there is a lot of fighting, reciprocal fighting and it can go on for over 10 minutes between two sows, and it’s quite violent.  Some of these animals are over 300 kilos, so you see they will push quite heavily against each other, but mostly it’s biting. They have got quiet sharp teeth and they can slash each other with them.After the hierarchy is established, so with time the fighting changes to be a bit more for priority access to a restricted resource; so often it’s food.  We see a bit more bullying in that case or dominant sows having achieved that position after mixing by fighting, it’s more one-way aggression towards more submissive animals.

DYANI LEWIS 
And I guess with pregnant sows you really want to be able to control the welfare for each individual sow.

MEGAN VERDON
Yeah, so for the pork producer the group housing is associated with a lot of risks in terms of producing the amount of pigs that they need to produce, and it’s because when sows are chronically stressed, or when any animal is chronically stressed, then this hormone cortisol is released into their blood and over the long-term it can have detrimental effects on their health and it suppresses the reproductive system. It’s also associated with the sow aborting and also reduced weight gain and not gaining access to the food as well.  We can see reduced litter weight, reduced litter size and more abortions associated with the stress in group housing.

DYANI LEWIS
So how do you go about assessing the level of aggression for individual pigs that might be housed together?

MEGAN VERDON
What I’m doing at the moment is looking at individual variation in aggressive behaviour and how that relates to an individual’s welfare.  Often in the past studies have looked at welfare and aggressional behaviour of the sows as a group average, and I feel like this can be a bit misleading because as we know animals, they don’t all show the same temperament or behavioural characteristics.So what we have done is we have just sprayed big symbols on their backs and we have groups of 10 so it’s easy to identify them, and we video record their behaviour after mixing and on the day after mixing, around feeding, and later on in gestation.So for each individual we can then watch how much aggression she delivers and how much aggression she also receives, and from that kind of determine a way of where she stands in the hierarchy.

DYANI LEWIS
What about if you were to take a pig, an individual pig away from a group situation, is there a way of determining their, I guess innate level of aggression?

MEGAN VERDON
That’s something else that we’re looking at.  Sows do vary individually and it means that not all their welfare is the same in these groups.  We need to find a way to identify those who are performing less well.Similar to the way dogs are tested in shelters, we are trying to design some temperament tests for these sows. The ones that we have found so far which have shown some level of consistency over age with the same sows is we introduce them to stalls - so a stall next to each other - and we watch how long it takes for them to try and interact.  We also introduce them to a stall with a fibreglass sow in the middle, and we use the fibreglass sow because it kind of standardises the procedure, whereas if you have them next to another sow her behaviour may depend on the sow who is next to her.  Whereas the fibreglass sow, it always looks the same.We have found that those sows who interact with the fibreglass sow or attempt to interact with her in under three seconds, there’s a 90 per cent chance that they will also deliver aggression on the day after mixing.

DYANI LEWIS
So how does this information about an individual pig’s aggressiveness help in pig management?

MEGAN VERDON
Via a number of ways, like firstly it is important for us to recognise that there are some sows out there who are doing really badly in group situations. There are also some that do really well. Those ones who are doing badly they do need to be identified.  It’s not good to have sows doing badly in group situations; otherwise they’re going from a bad system to a bad system.So it’s important for the farmer that we can identify them.  It’s important that we try and find a test which could be quick and simple to identify them with as they don’t have a lot of time already.At the moment people try to reduce aggression by controlling the environment or changing the environment, but as pigs are social animals this group dynamics and group composition is equally as important as the environment in which they live in.  So we need to start looking at how we can help them achieve a hierarchy more quickly, or understand that they operate individually in order to understand how the social group works and hence try and reduce aggression by that mechanism.

DYANI LEWIS
So you wouldn’t necessarily be weeding out the aggressive pigs, but just creating more of a natural situation, is that right?

MEGAN VERDON
Yeah. It’s quite interesting, because there have been thoughts of trying to weed out the aggressive pigs and going down genetic paths of selecting against aggressiveness, but if you look at the wild situation, the wild social group, then all animals exist in that group, so it’s possible that these aggressive dominant pigs are needed to help stabilise the structure of the group in the long run.For example, if we weed them out and we end up with a group of sows who are submissive, does one of them just jump up and be dominant or if we have a clearly dominant sow in with the clearly submissive sow we might see less aggression there because the submissive sow would just automatically submit to the dominant one and there’s no need for fights.

DYANI LEWIS
Sounds really interesting.  Thanks a lot for telling us about your research.

MEGAN VERDON
Thank you for having me.

DYANI LEWIS
Megan Verdon is conducting her research into pig welfare at the Animal Welfare Science Centre here at the University of Melbourne.Relevant links, a full transcript and more info on this episode can be found at our website at upclose.unimelb.edu.au.Up Close is a production of the University of Melbourne, Australia. This episode was recorded on 6 December 2012. Producers were Kelvin Param and Eric van Bemmel.  The Associate Producer was myself, Dyani Lewis, with audio engineering by Gavin Nebaur. Up Close is created by Eric van Bemmel and Kelvin Param.Until next time, goodbye.

VOICEOVER
You have been listening to Up Close.  We’re also on Twitter and Facebook.  For more info visit upclose.unimelb.edu.au. Copyright 2012 The University of Melbourne.


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