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 Living Links, 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.

 

Reference:

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.

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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.

 

Reference

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

 

Living Links changing the way animal social cognition is measured. Are photograph measures reliable?

Kirsty & BlakeWritten by Kirsty-Marie Moran & Blake Morton with thanks to Alaina Macri and Christoph Voelter.

 

 

I think we could all agree that seeing a photo of a person or place is different to seeing that person or place in real life…right? We react differently to photographs. For instance, if there was a picture of your boss, this wouldn’t stop you checking your private emails, would it? But if this person was there, it might. So, recording the behavioural responses to a photograph in humans, couldn’t possibly be representative of how humans would react to the real-life scenario.

However, this is exactly what is happening when measuring responses to photographs in primates. Scientists often use photos to test how animals perceive the world around them. For example, to test whether a dog can tell the difference between a happy versus sad person, they might record whether the dog whimpers more when it sees an image of a person crying versus laughing. Scientists can use photos instead of real-life stimuli to study animal behaviour because they’re cheaper and easier to bring into the lab. But in the absence of depth, smell, and movement, most animals can likely tell the difference between a photo versus the real thing. Behavioural responses to photos are interpreted to reflect how the primate would react in the real-life situation. Thus, recording how animals react to photos may not necessarily tell us how they would behave towards the same scenario in real life. Surprisingly, very few scientists take this problem into consideration when interpreting animals’ responses to photos.

In a recent collaborative study between Living Links and the Language Research Center of Georgia State University, Morton et al. (2016) investigated for the first time whether brown capuchin monkeys react to photos of the alpha male of their group (see below) in the same way as they do in real life.

LL morton experiment picture

Typically, lower-ranking capuchins react to the presence of an alpha male by either avoiding them or acting submissively in their presence (e.g. letting the alpha have first dibs on food). By placing food in front of a photo of the alpha male and then doing the same but in front of the real-life alpha, the researchers were able to compare whether the monkeys’ behaviour towards the photo could predict what would happen in reality.

The researchers found that the capuchins did not react to the photo in the same way as they did to the real-life alpha. Thus, a picture of their “boss” (the alpha male) did not fool the monkeys, let alone prevent them from grabbing the food next to the photo.

This study provides scientists with an important cautionary note when using photos to study animal behaviour.

Morton, F. B., Brosnan, S. F., Prétôt, L., Buchanan-Smith, H. M., O’Sullivan, E., Stocker, M., Wilson, V. A. (2016). Using photographs to study animal social cognition and behaviour: Do capuchins’ responses to photos reflect reality? Behavioural Processes, 124, 38-46. doi:10.1016/j.beproc.2015.10.005