The Importance Of Natural Stimuli For Captive Animals
According to a broad range of research, humans tend to show a preference for natural over built environments; looking at money as a metric of value, proximity to vegetation, bodies of water, and natural landscape views all increase the value of real estate, while artificial stimuli have the opposite effect, as views of buildings, for example, reduce the value of property. This preference for natural over artificial views is also true for photographs and other forms of visual media, and humans often also show a preference for natural sounds over artificial ones, though this correlation is not as strong, and studies are not as extensive.
This was intended to encourage further research on animal welfare, based on research done on human welfare. Since studies have shown that humans have beneficial reactions to natural stimuli, the researchers believed that we should examine the effect of these natural stimuli on captive animals in farms, laboratories, and zoos. The study begins with an examination of how humans react to natural stimuli as opposed to anthropogenic stimuli.
Aside from personal preference, natural stimuli have been shown to help us psychologically. A British study of 20,000 participants used cell phones to determine this; the participants were asked to report their psychological well-being while an app tracked their location to determine whether they were in natural or human-made areas. This variable was isolated through control questions, eliminating possible influence of whether the participants were at work or leisure, alone or with friends, etc. The study concluded that people are happier when outdoors in natural areas as opposed to artificial ones.
Meanwhile, a Danish study found that proximity to green space is associated with lower feelings of stress, and a Dutch study found that anxiety and depression were negatively correlated with proximity to vegetation. Water is also found to be a similar stress-reducer; of the vegetated areas used in the British study, those bordered by water were found to be those where people are happiest. These benefits were also found to hold true in Japan, through a government-sponsored study of “forest bathing” – spending extended time in wooded areas. Furthermore, studies have found that these psychological benefits can be found even in people who are exposed to natural stimuli only from window views, videos, and photographs of nature.
Importantly for the purposes of this study, the benefits that may be derived from some natural stimuli appear to be universal – culture, socioeconomic status, race, and gender do not significantly affect the outcome. This suggests that our affinity for certain natural stimuli is innate, rather than taught. This assertion is further supported by studies of infants, who are able to distinguish between natural and artificial phenomena, and seem to prefer the former to the latter. Furthermore, this preference may not even be conscious; studies have shown us to be better and quicker at identifying natural stimuli in rapid object detection tasks.
The authors extrapolate from this information that certain natural stimuli may be beneficial for non-human animals as well. They clarify that not all natural stimuli are beneficial, and that exposure to the natural world can come with its own risks to animal welfare. However, they also bring up studies showing that farmed animals consistently choose to spend time outdoors when given the choice, even in bad weather. There is also limited evidence that they are likely to use windows to view the outdoors, when possible.
Finally, there are some studies that show physical and mental health benefits to some natural stimuli: pigs are less prone to destructive behavior when given natural bedding, and lab rats given natural items in their cages appear less anxious than those in completely artificial environments, for example. However, these are rough observations, and confounding variables have not been completely accounted for. Many animals on farms, in laboratories, or in zoos could be studied in scenarios that account for more variables, as their lifestyles tend to be monitored and controlled since birth. Though studying captive animals may not ever be ideal, in this case it would be done to actually provide a better life for other captive animals.
For animal advocates, the study is an interesting twist: while animals are often studied in an attempt to improve human lives, in this case researchers are using human data to potentially improve captive animals’ lives. In addition to improving captive animals’ lives, the authors stress that findings of further experiments could give us more understanding of the mechanisms by which these natural stimuli improve our lives, as well as possible explanations for our innate preference of them. For animal advocates, however, improving captive animal welfare is a noble end in itself, and likely requires no further benefit to humans to be relevant.