Designing experimental apparatus for monkeys!

Written by Dr Emma McEwen

In many of the experiments at Living Links we use physical apparatuses that the monkeys can interact with, like different puzzle boxes, enrichment containers, dispenser shoots or objects for them to explore. When we design these new apparatuses, there are lots of different considerations we have to be aware of, and its often a collaborative effort between the researcher, the keeper team, and our Psychology & Neuroscience workshop to come up with the best solutions!

Our primary concern is always the safety of the monkeys, and of the experimenters. We always have to consider that a material is safe for the monkeys to touch in a way that they can’t get hurt, is non-toxic and easily cleaned so that it’s safe for their food rewards to touch, and something they can’t pull into their enclosure and do damage with.

Some design process stages including workshop cutting of materials, sketches and mock up protocol

Secondly, it has to be durable – capuchin monkeys can be stronger that you might think! We always have to consider the durability of the materials we use, making sure they can’t be easily torn or snapped, and that the monkeys can’t knock them off the experimenter’s table.

It also has to be enjoyable – we always want our research sessions to be enjoyable experiences and only positively reinforce behaviour. This includes only using materials and apparatuses that the capuchins enjoy interacting with. Sometimes, it can be difficult to predict whether they will enjoy touching certain materials. For this reason, we sometimes run some taster sessions, called pilot sessions, to offer the monkeys a chance to interact with a material or part of an apparatus before we build the finished product.

Two types of flap material (green plastic and black silicone) and a monkey reaching into the flap box for a reward!

For example, myself and my collaborator Andreea Miscov are currently testing two types of material to be used as potential ‘flaps’ for a grid box the monkeys will need to search for food rewards in, as part of a memory experiment. One is a silicone material and the other a harder plastic material. There are often individual differences between monkeys, and while some of the monkeys have no problem touching the silicone material, others have not wanted to! On the other hand the plastic material seems preferred from pilot testing so far. It can be important that there are no major differences between how the monkeys interact with apparatus, especially with experiments looking at time measures (a monkey less keen to touch an area of the apparatus will take longer to get their food reward!).

Video example showing durability test, prototype flap box and piloting with the monkeys!

Last but not least, it must be practical – for the designs of our experiments, we need our apparatuses to function in particular ways such as hiding food, sliding things into other things, moving in certain ways, or having certain weights. It can sometimes take us lots of time and trips to hardware shops to browse different materials and find the one that functions or moves in the exact way we’ve dreamed of when designing the experiment!

It can be very challenging to find something that fits all these criteria, but it’s a fun problem to solve!

Squirrel Monkey Training at Living Links

Written by Kenna Valles, Keeper, RZSS Edinburgh Zoo

Training in zoos provides several benefits to the animals and keepers. Training helps to keep animals both physically and mentally stimulated, while building a positive relationship between the keepers and animals, increasing the trust and communication between the two and encouraging animals to voluntarily participate in veterinary and husbandry procedures. This both builds the animal’s confidence and reduces their stress levels during these necessary events.

Figure 1: Squirrel monkeys playing in their enclosure

Just like for your pets at home, veterinary procedures in particular can be very stressful for monkeys; they often have to be separated from their group in a smaller area of the enclosure, sometimes physically restrained and handled by the keepers, without an understanding of why. However, to keep our animals healthy, these procedures are necessary to carry out regularly. Specifically training animals for veterinary purposes decreases an animal’s fear towards these procedures, allowing them to cooperate in their veterinary care and associate the procedure with a positive outcome by giving them a reward for participating.

The training performed at Living Links by keepers uses exclusively positive reinforcement techniques. This means that the training is voluntary to participate in and the monkeys are given a valuable reward, such as a food item, for performing a desired behaviour, without any punishment for not performing a behaviour. It is also perfectly acceptable for an animal to choose not to engage in training and their daily routine will continue as normal. Our research activities followed a similar training strategy, with the monkeys developing over the years a strong positive association with our research cubicles, the fun cognitively enriching games, and very tasty food rewards! Monkeys voluntarily come into the cubicles to take part as they find the experience so positively rewarding, and it’s this that keeps them returning each day for research.

Figure 2: Dominant male Boa from the ‘East’ squirrel monkey group taking part in scale training

The keepers have been training the monkeys to have this positive association with various veterinary procedures, such as voluntarily sitting on a weighing scale to check body weight (one important indicator of overall health) and entering an area of their enclosure called the ‘holding area’ which is used for veterinary checks and procedures.

To encourage the monkeys to start coming into the holding area and build a positive association with it, keepers rewarded each monkey for coming in by giving them a raisin, a highly valued food reward. When the training first started, the “West” monkeys were very nervous coming into the holding area; only around eight monkeys would come in for a raisin and they would then immediately run back out again. However over several training sessions, the monkeys started to become more confident and trusting of coming into the holding area and soon all 16 “West” monkeys were coming in for raisins! They also became more comfortable staying in the holding area for longer periods of time and now most monkeys will stay there eating for several minutes before leaving.

Figure 3: Keeper Kenna Valles training the squirrel monkeys in the holding area

Prior to this training, when the monkeys were closed in the holding area for procedures, they would be visibly stressed and huddle in a large group in a corner. During the annual vaccinations a year ago, only one ‘West’ squirrel monkeys voluntarily entered the holding area, but this year, after all the hard work with training, all 16 monkeys chose to come in by themselves! In addition to this they were not huddled together and instead were wandering around the holding area and continued to come to the keepers for raisins, suggesting they were significantly more comfortable being in the area than previous years. This is a really great success for both keeper and monkeys!

The “East” squirrel monkey group have also been participating in the same training but have a bit more work to do before they reach the same comfort level as the ‘West’ group, but the keepers are confident they will get there! It is still stressful for the monkeys when the actual procedures are carried out (i.e. injections, being weighed) but Kenna and the keeping team hope to work on training them for these procedures as well, and hopefully with enough training, the monkeys (both our squirrel monkeys and our capuchin monkeys) will eventually be comfortable participating in any veterinary procedure.

First Impressions- a research intern’s view

Written by: Wilson Chen

Hello, and welcome to the Living Links Blog! My name is Wilson, I am a second-year psychology student at the University of St Andrews. I am currently working in a public engagement with research internship at Living Links. I was interested in an internship at Living Links because I wanted to learn more about the role of monkeys in the study of behaviour and cognition. Moreover, I believe that bridging the gap between psychology research at Living Links and the visitors at Edinburgh Zoo is a meaningful endeavour that can promote and educate the public about psychology as a scientific subject.

Starting a new internship in a zoo can be both exciting and nerve-wracking. I may have been looking forward to this opportunity for a long time, but it can be hard to know what to expect when you’re stepping into a new environment with new people and animals. In this blog post, I will talk about my first impression of the centre and share some of my experiences talking to visitors during my first weekend as an intern.

            Originally, I thought the first thing I was likely to notice was the smell. The smell of monkey enclosures can be quite striking, as primates have strong body odour and produce a lot of waste. However, I was pleasantly surprised at how everything is clean and tidy at Living Links. The environment on the main platform (which is where I spend most of my time working) is fantastic. I can get a great view of both the east wing and the west wing enclosures. It can get quite chilly sometimes, especially when the wind picks up, but I am sure the weather will be much more pleasant when spring comes around.

            Whether it’s to see the exotic animals or to learn about wildlife conservation efforts, visitors often come with their own expectations and interests, and it is very apparent that most visitors are very engaged with the experience Living Links has to offer. When I approached visitors about doing a visitor feedback survey, many visitors reacted positively. To be completely honest, I thought I was going to get shut down most of the time, but I was happy to be proven wrong. Visitors of all ages can be seen at Living Links, and we see a lot of families. For the children coming with their parents, this could well be their first time learning about scientific research. The Living Links centre could be a great starting point in children’s engagement with scientific inquiry and the nature of science.

            While walking around the place asking people to fill in surveys about visitor experiences, I get a lot of opportunities to watch the capuchin monkeys go about their day. As I started to observe them, I began seeing a lot of similarities between their behaviour and human behaviour. Capuchins are social animals that form complex relationships and have a wide range of emotions. Watching them interact with each other can be very fascinating and heart-warming. You may also be struck by how intelligent they are, as you observe them playing, using tools, and communicating with each other in sophisticated ways. One thing that stood out to me is the similarity between the dietary habits of capuchin monkeys and human beings and how they do a lot of the same things as humans. They will remove seeds from food like bell peppers and skin from chickpeas (I noticed they are particularly efficient at this one). Compared to larger mammals who are often seen inhaling entire pieces of food at once, capuchin monkeys are more advanced in their methods of dealing with food.

            Perhaps one of the most rewarding aspects of interning at Living Links is the opportunity to build an understanding of the monkeys. Obviously, I am not there yet as I can barely recognise a handful of monkeys. But I hope that over time, I will be able to tell them apart, get to know each individual’s unique personality and preferences, and develop a deep appreciation for the complexity and beauty of their lives.

            I am looking forward to the rest of my internship at Living Links and I am sure this will be an eye-opening experience.

Understanding primate feelings through their personalities – a keeper insight.

Written by: Kirsty-Marie Moran

Personalities come in all shapes and forms, contributing to what makes you different from another person. It is also an intriguing aspect of ourselves that we share with our primate cousins. We can ask each other if we are well but with animals, this is not so easy. It is each individual primate personality that could be the key to understanding how primates feel and because we are unable to ask how they feel, we can only observe and record what we see. 

There are several ways in which researchers have attempted to answer questions on how primates feel such as taking blood samples, measuring hormones, or sitting observing behaviours.

However, in a recent study at the National Institutes of Health, Georgia State University, the researchers asked for the help of the keepers – after all, many of them have spent years with these animals. Who would know the personalities of the primates better?

Positive allo-grooming. Known to strength the relationship between the giver and receiver.
Positive behaviours. These brown capuchins are engaging in some allogrooming.

Using a questionnaire based on studies of people’s happiness it has been possible to assess happiness in nonhuman primates. With many studies suggesting the results are similar to that of humans. In humans, happiness and welfare are directly linked and the study at Living Links attempted to assess welfare and subjective well-being (SWB) in brown capuchins. In doing this they aimed to determine if happiness and welfare are directly relatable in capuchins.

It was found (between 10 keepers and over 200 ratings completed), that there was a high agreement on the capuchins welfare. Finding no difference between SWB and welfare ratings, which suggests that like humans SWB and welfare are linked. Also, any low ratings of SWB and welfare ratings were found to be associated with the display of stereotypic behaviours (i.e. self-grooming), indicated that a questionnaire which took on average 3minutes could be a quick and reliable form of studying welfare.

This may change the way welfare is studied in the future. With findings such as these, it may be worthwhile incorporating SWB and welfare related questionnaires into any welfare related research in the future. Especially when you are lucky to have keepers who have spent considerably longer with these animals than the researcher (in most cases) has.



Robinson, L. M., Waran, N. K., Leach, M. C., Morton, F. B., Paukner, A., Lonsdorf, E., Weiss, A. (2016). Happiness is positive welfare in brown capuchins (Sapajus apella). Applied Animal Behaviour Science, 181, 145-151. doi:10.1016/j.applanim.2016.05.029

The effect you as a ‘visitor’ have on squirrel monkeys.


Written by Kirsty-Marie Moran and Zita Polgár

Ever wondered if the animals at the zoo notice your presence? And if they do, if they mind you peering in on them?

These are very important welfare questions with many zoos attempting to answer them, including our very own here at Living Links Research Centre situated within Edinburgh Zoo. A recently published paper in the American Journal of Primatology details the results of a study examining the ‘individual differences in zoo-housed squirrel monkeys’ reactions to visitors, research participation, and personality ratings’. The study tackles the important question on whether monkeys with different personalities react differently to visitors, as well as how the size of the visiting groups influences their responses. Understanding individual differences is important because it can improve the animals welfare by catering to each individual’s needs.

During the study, the researchers recorded how long the monkeys spent by the observation window when there were small groups of visitors, large groups or no visitors. They found that the monkeys spent more time up at the window when there were large groups of visitors than when there were small groups or no visitors at the observation window. Specifically, the researchers found personality differences between the monkeys. Those who scored higher on playfulness and scored lower on cautiousness, depression and solitude were more likely to be at the window when there were visitors there.

These results suggest that zoo visitors do not have a negative impact on the squirrel monkeys but rather have a positive impact. Zoo visitors appear to be a form of enrichment, especially in those monkeys with social personalities.

The researchers speculate that the squirrel monkeys at the centre have developed this response due to a number of factors, namely that they are provided with a variety of enrichment opportunities. They frequently have positive interactions with a variety of humans through voluntary research studies and they have the option to choose from five different enclosure areas with different levels of exposure to zoo visitors.



Polgár, Z., Wood, L., & Haskell, M. J. (2016). Individual differences in zoo-housed squirrel monkeys’ (Saimiri sciureus) reactions to visitors, research participation, and personality ratings. American Journal of Primatology. doi:10.1002/ajp.22639


What does it mean to be a Living Links researcher?


Written by Sophia Daoudi

Walking through Living Links you may have either seen someone industriously walking around with a clipboard and binoculars or in one of the monkey interview rooms dressed up in a boiler suit. These are the researchers at Living Links. Researchers upstairs will usually be observational researchers and downstairs, experimental researchers, studying the monkeys cognitive abilities (e.g. how good is their memory), prosocial behaviour (are they able to share) or their ability to use tools.


All research is approved by RZSS Edinburgh Zoo and Scottish Primate Research Group. The current Living Links team include, Donald Gow- Animal Research and Team Leader, Dr. Lara Wood- Research Coordinator, and Prof Andrew Whiten- Scientific Director. A lot of time and effort goes into the approval process, so it’s really important to do thorough background reading and know your subject area well. A successful applicant then goes through all the necessary induction and training at Living Links, receives a research badge and start date and finally it feels official.

Now comes the tricky part, it is essential that we know who is who. I remember the first time that I studied the capuchins and squirrel monkeys back in 2009, the groups were smaller then, but even so I thought “how on earth am I going to learn all of these monkeys?”

Initially they all looked the same and I would spend hours on the observationjunon2 deck looking at them.  The more I watched them, the more I realised that they did, indeed, look different and have their own individual personalities. Looking back it now seems silly to think that they all looked the same. For instance, Junon (one of the adult female capuchins from the East group) has a white outline of fur around her face, she is quite gentle and moves cautiously.


Often the easiest individuals to identify in each group, for both species, are the alpha males, as they are usually the largest. Nowadays, there are around 66 squirrel and capuchin monkeys with babies being born throughout the year. Thankfully, the squirrel monkey each have an individually recognisable tag, but you still need to learn which colour represents which individual before you have any chance of passing the id together

Then the fun begins, and even though there can be frustrations, such as the monkey you are watching disappears half way through the study period or you note something down and when you look back you can no longer locate them, getting to observe the monkeys in their day-to-day lives is such as wonderful experience and there is never a dull moment.

So if you are thinking of sending in a research proposal, hopefully, now you’ll have a bit more of an idea of what goes on and remember as a researcher you need to be flexible and allow enough time to collect all of your data, this way if/when, you have a “bad” day, you are less likely to panic with looming deadlines. Getting to observe the monkeys in their day-to-day lives was such a wonderful experience and there was never a dull moment. I wish I could do it all again. Now I have the joys of analysis to turn to but I’ll save that for a whole other blog.

‘I wanna talk like you’ – New chimp arrivals pick up the same calls as Edinburgh Zoo’s old residents.

louis by jamie norris

New research led by scientists from the University of York and the University of Zurich provide the first evidence that chimpanzees can ‘learn’ calls that refer to particular objects.

The paper by Watson, SK., Townsend, SW, Schel, AM., Wilke, C., Wallace, EK., Cheng, L., West, V. and Slocombe, KE. ‘Vocal Learning in the Functionally Referential Food Grunts of Chimpanzees’ has just been published in Current Biology.

Over many years researchers here at RZSS Edinburgh Zoo have been studying the various food calls of our chimpanzees. Dr Katie Slocombe, one of the senior scientists on this recently released paper has been involved in researching Edinburgh’s chimpanzees since 2002, so she and her colleagues have gathered a great wealth of knowledge on our troop.

If you are a regular follower of this blog or a visitor to Edinburgh Zoo you may know that in 2010 a new group of adult chimpanzees from Beekse Bergen Safari Park in the Netherlands were integrated with our Edinburgh chimpanzees. These new additions to our troop gave researchers a unique opportunity to investigate whether chimpanzees can change their food calls when they become incorporated into a new group.

Chimpanzees give distinct grunts when they find different types of food, and other chimpanzees understand the meaning of those grunts. They will give a high pitched sound for a preferred food and lower for less preferred item. Katie, Stuart and their colleagues found before integration the animals had different grunts for apples as well as different preferences for apples. They discovered that the Dutch chimpanzees modified their grunts referring to apples so that, three years after integration of the two groups, their calls were very similar to those produced by the resident Edinburgh chimpanzees.

Does this mean our Dutch chimps have learnt to speak Scottish?

Want to learn more about how we study chimpanzee communication, watch one of our learning resources videos.



or click on this BBC news link below to hear more about this amazing research and what our zoo visitors think too!




MOOC filmed at the Zoo


Have you ever taken a MOOC, a Massive Open Online Course? MOOCs are open access, unlimited participation courses that you can take from many leading Universities.

University of Edinburgh lecturers Dr Kenny Smith and Dr Suilin Lavelle filmed here at Edinburgh Zoo this summer to highlight many aspects of their course.

The full online MOOC entitled Philosophy and the Sciences is 8 weeks long and is split in 2 parts.

1.Philosophy of Physical Sciences

2.Philosophy of Cognitive Sciences

The discussions and topics in Part 2 are wonderfully highlighted by our capuchins and chimpanzees here in Living Links and the Budongo Trail.

Kenny and Suilin discuss how animals  have not only evolved by physically adapting to their environment but also mentally.  In addition they discuss how social learning can create animal traditions or cultures. Cultures such as different means of using tools in various chimpanzee or capuchin groups.


Click on the link below to sign up to the MOOC!

Please Knock

inti says please knock





Reliably signalling a startling husbandry event improves welfare of zoo-housed capuchins (Sapajus apella)

Kristina Rimpley and Prof Hannah Buchanan-Smith of Stirling University examined the effect of giving the capuchins a reliable signal (a knock on the door) 3 seconds prior to a keeper entering the enclosure to perform a husbandry event. The study hypothesised two main things;

1. That unreliable signals that indicate husbandry events may have a negative impact on capuchin behaviour.

2. Making a husbandry event predictable will decrease anxiety related behaviours prior to the husbandry event.

To address these hypotheses the researchers studied 12 of the capuchins at Living Links, 6 from the West and 6 from the East. Behaviours that were used as indicators for anxiety levels were scratch, vigilance and jerky motion.behaviour categories for please knock






Baseline information was gathered on the monkeys’ behaviour 5 minutes before and after door events, with a door event being defined as the opening and/or closing of any door in the keeper area which could be heard by the capuchins.

knock before you enter diagram






As you will see in the figure above there are many doors in the keeper area and they may be opened or closed for a variety of reasons. Thus hearing a door could not predictably signal a keeper would enter a capuchin enclosure. In fact only 30% of door events resulted in a keeper entering a capuchin enclosure.

Therefore the researchers implemented the treatment of the door knock 3 seconds prior to a husbandry event to allow the capuchins a predictable indicator that a keeper was about to enter. The capuchins were given 2 weeks to get used to knocking as a signal then observed again to see if their anxiety levels had changed towards door events.

picture 2 for please knock







The results indicate that there was a decrease in anxiety related behaviours of the capuchins in the after door event in the treatment phase, thus supporting the notion that giving the animals a predictable indicator of events can benefit the overall welfare of the monkeys.

This is a great technique that can be implemented very easily for no cost and no additional time and can have a great benefit to all our monkeys’ well being.


Rimpley, K and Buchanan-Smith, H (2013). Reliably signalling a startling husbandry event improves welfare of zoo-housed capuchins (Sapajus apella). Applied Animal Behaviour Science. 147, 205-213.

Royal Society of Edinburgh (RSE) honours Prof Andy Whiten

andy medal newsProfessor Andy Whiten the Director of Living Links has been awarded the Sir James Black Prize and Medal.

He has been bestowed this honour due to his outstanding work in primatology and his innovations within the field of social learning and the cultural transmission of behaviour.

Later on this year he will be giving a guest lecture for RSE entitled “Social Learning and the Cultural Transmission of Behaviour in Human and Non-human Animals: A ‘Second Inheritance System’ in Biology.”

As soon as we know the date and location for this lecture we will post it up here on the Living Links website.