Animal Welfare: In the Dark – Aardvark Well-Being

If you share your home with an animal companion, have you ever wondered what he or she does when you are not home? Some people install cameras that allow them to use their phones to take a peek at what their dog is up to, or where the cat is spending her time. We also wonder about what animals do at the Detroit Zoo when we are not here, and this is especially true for nocturnal animals who are most active when we are sleeping. Aardvarks are one of those species, and the Detroit Zoological Society has been using cameras to study their behavior.

Aardvarks are native to sub-Saharan Africa, and not only are they primarily nocturnal, but they are also fossorial, meaning they dig and burrow underground. This makes them even more challenging to observe, as you can imagine! The four aardvarks who live at the Detroit Zoo are cared for by the night keeper unit, whose hours allow for expanded opportunities for animals, including those who are active later into the night. The staff come up with creative ideas to engage the aardvarks and stimulate natural behaviors.

We installed a number of infrared cameras in the habitat, allowing us to record what the aardvarks do and where they choose to spend their time. Initial research revealed that they had specific preferences, such as sleeping in culverts, which are reminiscent of underground burrows, and that their activity levels varied by individual. Roxaanne, one of the females, preferred to stay up much later than the others, for example. Additionally, we found that when the aardvarks engaged in more investigative behaviors, they had lower fecal glucocorticoid metabolite (FGM) concentrations. Decreased levels of FGMs have been correlated with lower stress levels and overall positive welfare. By taking behavior and hormones into account, we get a more comprehensive picture of the well-being of the aardvarks under different conditions.

Jennifer Hamilton, DZS animal welfare programs coordinator, worked with the animal care staff to develop a new project aimed to increase behavioral opportunities for the aardvarks, by specifically targeting more foraging and investigative behaviors. Jennifer and a small team of dedicated volunteers watched more than 220 hours of “aardvark television”. Talk about binge-watching reality TV! In addition to the behavioral data, the care staff once again collected daily fecal samples on each aardvark so that we could analyze them for FGMs.

Higher levels of investigative behaviors were again linked to lower levels of FGMs. This suggests that these types of behaviors are important for aardvarks and need to be encouraged. The behavior data also showed that foraging opportunities were used for longer periods of time when initially presented, but that investigative opportunities were used more as the night went on. As part of the project, the aardvarks were presented with seven opportunities once a week for eight weeks. We were able to confirm that the aardvarks did not lose interest over time, meaning that repeated interactions don’t bore them! Finally, the aardvarks’ use of the opportunities differed based on their location. The aardvarks have access to different spaces, which vary in their substrates and features. One of the spaces has a very large and deep dirt area, and the aardvarks spent less time engaged in the extra opportunities provided when in that habitat. This may be indicative of a flexible value system, with less value placed on additional opportunities when overall conditions may already be more stimulating. This is an important concept as we explore what type of choices are meaningful to animals and how to create environments that enable them to thrive.

– Dr. Stephanie Allard is the director of animal welfare for the Detroit Zoological Society and oversees the Center for Zoo and Aquarium Animal Welfare and Ethics.