Staff from the Detroit Zoological Society’s Center for Zoo Animal Welfare and Ethics have been observing the barn owl living at the Detroit Zoo to study his sleep patterns. Jim’s home in the Barn is a popular spot for visitors – Thoroughbred horses, donkeys, steer and pigs also live there. And while barn owls are nocturnal, spending the majority of the daylight hours sleeping, the noises and activity in the Barn may cause mild disturbances during the owl’s normal sleep cycle. Jim has lived at the Detroit Zoo for many years and appears to be healthy and happy, but it is important that we look at other measures of welfare.
Sleep patterns and sleep quality have been proposed as animal welfare monitoring tools, as links between well-being and sleep have been documented in humans. If you have gone through stressful times in your life, you may have experienced poor quality sleep, perhaps waking up more often. Similar effects have been found in other animals, such as rats and chimpanzees. However, poor sleep itself can also have an impact on welfare. Rats whose sleep cycles were disturbed by routine caretaking activities were found to groom themselves less and engage in fewer enrichment-related behaviors.
Sleep research typically makes use of electroencephalograms (EEGs) – which use small sensors attached to the head to measure brain activity – as well as other types of devices, which, as you can imagine, could be disruptive and rather challenging to use with animals living in zoos. We are therefore using behavioral and endocrine measures as non-invasive means to assess the welfare of the barn owl in relation to environmental factors such as noise.
We made observations of the barn owl’s behavior multiple times each day, primarily focusing on body and head position and degree of eye closure. We also recorded noise levels and other environmental factors. Fecal samples are being analyzed in our endocrinology lab by Dr. Grace Fuller, manager of applied animal welfare science and Jennifer Hamilton, applied animal welfare programs coordinator, to look for any changes in hormone levels. The samples were collected on a daily basis by animal care staff and prepared for analysis by our dedicated volunteers, whose help is invaluable!
The barn owl’s behavior could indicate how well he is sleeping and if any external factors are contributing to his sleep patterns. The hormone analysis – along with data on his food consumption – will be a way for us to validate the behavioral information we gathered. If we understand how to measure sleep quality non-invasively, we can apply this methodology to other species and expand our toolkit to monitor animal welfare.
– Dr. Stephanie Allard is the director of animal welfare for the Detroit Zoological Society and oversees the Center for Zoo Animal Welfare and Ethics.