Written by EMILY ANDERSON, ROBERT WELADJI, and PATRICK PARÉ
Like many others, we have fond memories of going to the zoo as children. It is such an iconic experience in a North American’s upbringing that there is even a children’s song written about it – people outside of Canada have heard of Raffi, right? However, few people know that zoos have existed for thousands of years (Fig. 1). Once mainly in existence for religious purposes or as a show of power and wealth, zoos slowly evolved into places for public viewing of exotic animals by the 16th century. It wasn’t until the founding of the London Zoological Society in 1826 that the research potential of animals housed at zoos began to be realized. The public was becoming more interested in the true nature of captive animals, and the zoo community slowly started shifting away from small, sterile cages towards a more naturalistic approach. Thus, the modern zoo was born! In the past two centuries, the zoo community has continued to progress with the growing prevalence of organizations, such as the American Association of Zoos and Aquariums (AZA), that promote scientific research and higher welfare standards. Despite the significant improvement in housing standards that has been observed over the years, the welfare of animals in zoos is still a hotly debated issue.Before we can delve too far into the zoo animal welfare debate, we must ask ourselves: what is welfare? Therein lies the problem. One of the major issues in welfare research is that welfare, as it refers to animals, has yet to receive a widely accepted and functional definition. The meaning often varies depending on whether it is being applied to agricultural animals, laboratory animals, or to companion animals. In general, welfare is considered to be the subjective quality of life experienced by an individual as determined by their physiological and psychological state. As welfare is subjective, it can only be assessed indirectly. To do so, we generally have to look at an animal’s physiology, such as measuring their levels of stress hormones, their productivity (e.g. growth and reproduction) and their behaviour, and whether it is considered “normal.” Based on these measurements, we are able to get an idea of an individual’s ability to cope with its current environment.
In a zoo environment, animals cope with many stimuli that are not experienced by their wild counterparts. Obviously, the near constant presence of large numbers of humans is one of the main factors that sets the zoo apart from the field and the laboratory. These captive animals also experience artificial habitats and social groupings that could inflict excess stress and, inevitably, cause deviations in behaviour. Though behaviour varies between species and between individuals, there are several behavioural indicators of low welfare that are commonly accepted. Stereotypic behaviours, that is, highly repetitive behaviours that appear to serve no proximate purpose, tend to increase in stressful situations. In addition to abnormal behaviours, any normal behaviour, such as self-grooming or resting, that is performed significantly more or less than in a wild individual, could be cause for concern in captivity. In particular, excessive aggression, directed either at other individuals or at oneself, is considered to stem from frustration. It is no surprise, then, that high levels of these indicator behaviours are often observed when animals are housed in small enclosures that lack complexity, or when they are surrounded by a high number of visitors.
Empirical studies are needed to fully understand how housing and husbandry practices impact the welfare of animals in zoos. Welfare has become a relatively common research subject in zoos; however, the majority of studies focus on the most popular and charismatic species – mainly the large cats and great apes. We set out to investigate the behaviour of two troops of Japanese macaques (Fig. 2) housed at the Zoo Granby, in Granby, Quebec, with the hopes of gaining some insight into their species-specific experience in captivity. Japanese macaques are one of the most studied primates in the wild and in research centers. These “snow monkeys,” as they are often referred to, are the most northern-living nonhuman primate (Yes, they are the ones you have all seen in photographs and on TV lounging in hot springs) and over 50 years of research has revealed a huge amount of information on their social structure, feeding habits, and natural behaviour. Despite this, not much effort has been dedicated to understanding how they react to the zoo environment. The first question we wanted to answer was: Does the behaviour of Japanese macaques in a zoo differ from the behaviour of those in nature?
We collected over 400 hours of observations between July and October, 2014. During this time, we observed everything from same-sex mounting to play-fighting in mature adults to an affiliative behaviour that can only really be described as “twerking.” There was even an interesting incidence of an individual chasing and accidentally killing a bird, which was followed by the entire troop taking turns grooming the poor dead thing (Fig. 3). The data collected were used to create a preliminary activity budget that could be compared to non-zoo populations. Specifically, it was compared to a troop of 24 individuals from western Yakushima and to a troop of 32–41 individuals housed in a large, naturalistic enclosure at the Primate Research Institute at Kyoto University, Japan. The results were not all that surprising. In short: yes, there is evidence that Japanese macaques behave differently in the zoo than they do in the wild or at the research center, but when we look at the frequencies of specific behaviours, things get much more interesting.
In the wild, the activity budget of Japanese macaques is mainly influenced by environmental factors, such as food availability, which do not apply to zoo populations. In extremely restrictive conditions, Japanese macaques have the potential to display many abnormal behaviour patterns commonly seen in primates in captivity. On the positive side, the Zoo de Granby Japanese macaques did not display an excessive amount of abnormal or aggressive behaviour. Aggression, directed at each other and occasionally at zoo visitors (and myself), only made up 4% to 5% of the observations, which is similar to what was observed in the research population (these behaviours were lumped into “Other” for the wild troop). Though abnormal behaviour was observed on occasion, most was performed by only two individuals: Shiwa, a relatively anxious, young-adult female and Remon, a young male who had been rejected by his mother as an infant and, consequently, was raised by hand.
All said and done, the activity budgets of both Zoo Granby troops were still very different from the wild and research populations used in the comparison. Vigilance was the most commonly performed behaviour (Fig. 4) in both the zoo groups but was relatively uncommon in the research population. Unfortunately, vigilance on its own was also not recorded for the wild population but was pooled into “other” behaviours, making any direct comparison of the behaviour impossible. As the zoo troops did perform more “other” behaviour than the wild troops, it is reasonable to assume this could be due to a difference in vigilance levels. It is possible that the high level of vigilance observed in the zoo was due to visitor presence, as the majority of the data was collected when the zoo was open to the public. Vigilance is a common anti-predatory behaviour; hence the macaques at the Zoo de Granby may view visitors as a potential threat to their well-being.
Vigilance was not the only behaviour that differed between the populations. Feeding was much less predominant in the zoo macaques than it was in the research and wild macaques. Both wild and research populations had access to a much greater diversity of plant life than is available in the Japanese macaque enclosure at the Zoo de Granby. Even when provisioned, macaques in a highly vegetated enclosure will still feed significantly more to supplement their diet with plant matter. Grooming was also observed much more often in the two zoo groups than in the research population (Fig. 5) and the wild population, and the number of self-grooming observations was particularly high. Beisner and Isbell (2009) speculated that grooming could actually be influenced by vegetation presence as well, as both foraging and grooming may fill a need for fine motor stimulation. An equally likely hypothesis is that the excessive amount of grooming in the Zoo de Granby macaques is linked to stress. Self-grooming, though playing an important role in hygiene and self-maintenance, is considered a displacement behaviour. What this means is when the animal is faced with uncertainty or conflicted as to what behaviour to perform (let’s say, whether to run away from zoo visitors or aggressively display at them), they perform a completely unrelated behaviour, such as grooming one’s self, scratching, or yawning. To make matters worse, many of the individuals at Zoo Granby are currently suffering from varying degrees of hair loss. This could be due to a number of causes ranging from hormonal imbalances to old age, but spending ten to twenty percent of your time grooming yourself probably wouldn’t help the matter!
In the past, researchers have suggested that, because captive animals feed less than their wild counterparts, it leaves them a large amount of time that must be filled with other activities. This may be true, and the Zoo Granby macaques did feed relatively little compared to the other populations, but we believe this statement oversimplifies the issue. One could argue that these animals are grooming more simply to fill their time, or that vigilance is not necessarily stress-related but the animals are simply interested in their surroundings. Without further research, we can’t know these things for sure. That is why the next step in this research project is to investigate how enclosure design and the presence of visitors impact Japanese macaque behaviour. Until we find a way to read the minds of animals, there will always be some ambiguity to the study of welfare, but if we are able to identify the conditions in which animals thrive at one zoo, we can work to replicate them in others and guide all zoos towards a higher standard of animal care.
Emily Anderson is an M.Sc candidate in the Biology Department at Concordia University, in Montreal, Quebec. Her field of research is applied animal behaviour, with a focus on primate behaviour and the welfare of zoo-housed animals
Dr. Robert Weladji is an associate professor of biology at Concordia University, in Montreal, Quebec. His research interest is rather broad and includes population ecology, behavioral and evolutionary ecology, wildlife conservation and management, ecology, and welfare of captive wildife.
Patrick Paré is a biologist and the director of the Research and Conservation Department at the Zoo Granby, in Granby Quebec. He has an M.Sc in science from Laval University