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.

Animal Welfare: The Sensory World of Wildlife

What sounds do you hear when you wake up? I sometimes hear my dog gently urging me to get out of bed. Sometimes I hear a car alarm, which is less pleasant. What do feel when you wake up? For me, it’s my toasty warm sheets and if I’m lucky, I can reach my hand out and pet my dog on the head. What do you smell? What do you see? What about during the day, or at the end of the day? We experience sensations all the time, even when we aren’t awake to realize it. What do those sensations mean to you and how do they affect how you behave?

Animals experience all of the things we do, but not necessarily in the same way. For example, depending on how their sensory systems function, they may smell things much more strongly than we do. A dog’s sense of smell is approximately 40 times stronger than ours. This means what odors we notice may be negligible compared to what they do. While humans typically rely on their eyesight as their primary sense, many animals see differently than we do. Birds and reptiles can see in the ultraviolet range. Raptors can see much further than we can, and some animals see more of what’s around them due to the placement of their eyes. Some animals, such as pit vipers, sense things using infrared sensors, which allows them to find their prey using heat signals. All of this means that animals experience the world very differently than we do, and this can impact their welfare. The senses of animals are essential for every aspect of their daily lives, from finding food and shelter to recognizing others as friend or foe.

If we are concerned about the well-being of animals, we must be aware of how they experience the world around them. We must also be considerate of how our actions can affect their perception. Animals living in their natural habitat are becoming more vulnerable to our actions, from birds colliding with buildings that are lit up at night, to frogs who have to compete with man-made noises to hear one another.

When it comes to animals living in the care of humans, this can also prove to be a challenge. We don’t know enough about how other species perceive their world, but we use the knowledge we do have to make the best possible decisions. For animals living in zoos and aquariums, we have a lot to consider. Ultimately, we are the architects of the homes for other species. Imagine if a zebra was in charge of designing your home. What if a snake built your office? The field of sensory ecology, which is the study of how organisms acquire, process, and respond to information from their environment, continues to grow. We use that information to help create habitats at the Detroit Zoo and Belle Isle Nature Center that provide animals with positive experiences. Additionally, we take the sensory perception of animals into consideration when we plan special events and construction projects, as sounds, sights and smells may impact individual animals. We also think about what animals live near each other. Can an animal feel threatened or positively stimulated by the sight, sound or smell of another species?

In our own lives, we are aware of which sensations make our experiences positive and which don’t. We are often in control of those experiences, or we know they are temporary. Animals may not have those opportunities, and it is our responsibility to ensure we are creating positive experiences and minimizing our own contributions to impacts on welfare resulting from sensory inputs. Take a moment to think about the experiences of the animals who share your home with you. Is there room for improvement? If so, come up with ways to mitigate any negative sensory impacts. Also, take time to think about how the animals as the Zoo feel if people yell at them or create conditions that alters their ability to use their senses.

Those of us who care for animals for a living have to be extremely sensitive to the ways animals perceive their environment. This important concept is part of what the Detroit Zoological Society’s Center for Zoo and Aquarium Animal Welfare and Ethics teaches each year during our workshops. We immerse the participants in animal habitats in various ways in order to change our own human perspective. The understanding each person gains from these experiences is an invaluable part of their toolkit to further the welfare of every animal with whom they work and live.

– 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.

Animal Welfare: Seal of Approval

The Detroit Zoological Society (DZS) is investigating the effect of foraging opportunities on the welfare of the seals who live at the Detroit Zoo. Foraging is a very important behavior category for animals, as it typically involves mentally and physically stimulating behaviors. Wild gray seals may spend up to two-thirds of their time searching for food. Although they do have well-developed hearing and sight, seals often rely on their extremely sensitive whiskers to locate the fish they eat. This is necessary as visual conditions underwater can be poor and swimming fish may not generate much noise as they move. Instead, the fish – and other prey items – create vibration trails in the water and these are the stimuli the seals’ whiskers detect. Research has shown that harbor seals can use their whiskers to distinguish between objects of different sizes and shapes – a skill they can use to select better prey items when hunting.

Seals living in zoos and aquariums don’t need to forage in quite the same way as they would in the wild, and thus may not engage in as many complex feeding behaviors. As part of her residency with the Center for Zoo and Aquarium Animal Welfare and Ethics, Sara Zalewski worked with DZS staff to design a project examining the impact of three different ways to increase foraging behavior in the gray and harbor seals living at the Detroit Zoo. The seals were presented with fish frozen in ice, fish placed on top of a floating disk and sunken tubes the seals needed to manipulate to allow fish to fall out of holes in the tube. All three items were used to increase the amount of the work the seals would have to do to get to the food. As part of this research, Sara found that the seals differed by both species and individual in how they used the items.

The gray seals interacted with the items most when they were first presented with them, and the harbor seals’ level of interaction increased as time went on. The likely explanation for this is that the gray seals were younger and more dominant, and thus were able to use the items more easily. Once they had their fill of the food, they would lose interest and the harbor seals could begin to investigate the items. Dealing with dominance hierarchies can create challenges when providing animals with resources, and is therefore something we have to keep in mind when thinking about the welfare of all of the individuals.

Another challenge was getting the seals to use the items for longer periods of time. It makes sense that less interaction occurs without the motivation of obtaining food, so there is a need for more challenging devices that require the seals to use more of their foraging abilities. One unexpected outcome was that Georgie, one of the female gray seals, would sometimes use a floating disk as a resting place later in the day. However, it could not support her body weight, so she would lay on it on top of something else, such as a ledge in the pool. Other studies have shown that gray seals’ preferred prey, haul out sites, and feeding locations and techniques differ greatly between individuals. Finding ways that items can serve more than one purpose and allow each seal to make use of them as they choose are also goals.

Harbor seals are an especially playful species, including as adults. However, as animals age, play and exploratory behavior tend to decrease, regardless of the species. Additionally, decreases in their sensory abilities may occur. This means that for Sydney, the older male harbor seal, opportunities may be more challenging or potentially less engaging for him.

In order to create more engaging ways for all the seals to forage, Sara worked with DZS staff to refine the items and will observe Georgie and Jersey, the two gray seals, and Sydney, the harbor seal, to see how the modifications affect their behavior. DZS staff members are creating floating devices that the seals can use to rest – as well as interact with for access to fish – and are changing the design of the tubes so that they rest standing up, rather than lying flat on the bottom of the pool. This should make it a bit harder for the fish to fall out, and will be more stimulating for the seals as a result. Finally, Sydney will have some alone time with the items, to ensure the younger and more agile females don’t deplete the food before he has a chance to interact with the foraging devices. During your next visit, you may see these items in the seal pool at Arctic Ring of Life. Although we are only observing the seals at specific times, incorporating these types of behavioral opportunities is part of our daily comprehensive program of ensuring the environments for all the animals at the Detroit Zoo are ever changing and appropriately complex.

– 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.

Notes from the “Field”: Expedition to the Detroit Zoo’s Otter Habitat

The Detroit Zoological Society conducts field conservation work all over the world; however, a recent venture required traveling only a few hundred feet from my office. Preparatory research for an upcoming trip to Armenia to preserve otters involved traversing the Edward Mardigian Sr. River Otter Habitat at the Detroit Zoo. Otters are classified as Endangered in Armenia, but there is no current data on their status. As part of this project, we will be assessing the status of these animals across Armenia and identifying important areas for protection. Early on, the focus will be on conducting sign surveys along rivers and streams, looking for traces of otters. Becoming familiar with otter tracks and feces was essential before this fieldwork could begin; where better to do such research than inside the otter habitat at the Detroit Zoo?

Armenia is part of the greater Caucasus biodiversity hotspot, and otters are an important part of the diverse fauna. The otters in Armenia are Eurasian otters (Lutra lutra), a different species from the North American otters (Lontra Canadensis) that are present at the Detroit Zoo. However, both otter species are similarly sized and they both have diets that consist primarily of fish, so their feces is likely to be similar.

Detroit Zoological Society animal care staff shared helpful identifying information inside the otter habitat, including the variability and size of the feces, which were less compact than one might expect. Scratch marks often accompany the feces, which also often occurs with snow leopards. In addition, because the habitat at the Zoo is cleaned regularly, it was clear how quickly the feces can degrade. Proper estimation of the age of feces can be important for estimating animal density.

We’ll be sure to report back with findings following our research in Armenia.

– Dr. Paul Buzzard is the field conservation officer for the Detroit Zoological Society, which is involved in wildlife conservation efforts on six continents.

Animal Welfare: More than the “Bear” Necessities

The Detroit Zoological Society (DZS) recently renovated the grizzly bear habitat at the Detroit Zoo, doubling the amount of outdoor and indoor space available to the three rescued brothers. Staff with the Center for Zoo and Aquarium Animal Welfare and Ethics are measuring changes in the bears’ activity budgets, behavioral diversity and fecal glucocorticoid concentrations to assess the impact of the expanded habitat. We will also be testing the efficacy of a biomarker of oxidative stress as a novel indicator of animal welfare.

The grizzly bears living at the Detroit Zoo, Mike, Thor and Boo, are brothers who were rescued in Alaska after their mother was killed by a poacher and the cubs began foraging too close to humans. At just a year old, they were too young to care for themselves and the DZS has been able to provide them with a safe place to grow up. The bears are now 7 years old and weigh approximately 900 pounds. With their inquisitive nature and significant strength, they frequently “redecorate” their habitat by moving logs around and digging in various locations. It became clear that they were outgrowing the habitat they called home since 2012.

As part of the DZS’s commitment to ensuring individual animals experience great welfare, a significant expansion of the grizzly bears’ habitat is underway. Not only will this augment the amount of land space available to the bears, it will also provide them with new behavioral choices. They will have access to more features such as caves to provide cool, shaded areas. The larger habitat will also increase natural foraging opportunities for the bears.

When we make changes that affect the lives of animals, it is important that we understand how those changes impact them. To that end, we began collecting data last fall, prior to construction, to obtain a baseline of the bears’ behavior and hormone levels. Observations continued during construction and will end two months after the bears move back into their renovated home. Zookeepers have also been filling out daily surveys to add to the information we are gathering. Fecal samples are collected daily and these will be analyzed in our lab to measure hormone levels related to how the bears react to these changes. Using these different types of data in concert will increase our understanding of the expansion effect on the bears’ overall well-being.

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.

Animal Welfare: If You Build it, They Will Explore

Juvenile Madagascar giant hognose snakes recently moved into new homes in the Detroit Zoo’s Holden Reptile Conservation Center and indicators measured showed this had positive welfare impacts.

Although Madagascar giant hognose snakes can grow to 6 feet in length, the individuals that live at the Detroit Zoo are still rather small, and have been living behind the scenes since they hatched two years ago. They have a distinctive upturned snout, which they use to burrow and search through leaf litter and other ground substrates in search of food and shelter. Several months ago, the reptile department created new, more naturalistic habitats for the snakes, providing them with additional opportunities to display species-typical behaviors.

These larger spaces were outfitted with multiple types of shelter and natural substrates such as sand, mulch and cork bark. Complex spaces with ample options for making choices can contribute to positive welfare and one of our recent residents at the Center for Zoo Animal Welfare and Ethics, Marisa Spain, decided to conduct a study examining the impact that these new habitats had on the snakes. Little attention has been given to the welfare of reptiles, and as such, less information is available about conditions in which they thrive than for mammals and birds. Marisa studied the snakes before and after they moved into the new spaces, spending hours recording their movements. In their new habitats, the Madagascar giant hognose snakes significantly increased their rates of tongue flicking, which is indicative of exploratory behavior. Similar increases have been seen in other reptile species and categorized as positive indicators of welfare. The snakes also increased how much time they spent burrowing, which is a species-typical behavior now better supported by their enhanced environment. The snakes exhibited more active behaviors in general, something we were hoping to see, as activity levels can indicate how engaged an animal is with its environment. The snakes also showed an increase in behavioral diversity, which is also being used as an indicator of positive welfare.

Overall, we were thrilled to see that the move to their new homes was a valuable change for the snakes. Reptiles perform activities for the same reasons other animals do; for example, to seek food, to explore and to find comfortable places to rest. Because of these welfare studies, we have a better understanding of how reptiles living in the care of humans are faring. All individual animals have welfare needs and while it is our responsibility to ensure those needs are met, it is also incredibly rewarding to see the animals thrive.

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

Uncovering Turtle Personalities

Several years ago, we developed a project through the Detroit Zoological Society’s (DZS’s) Center for Zoo Animal Welfare to determine if we could identify specific personality traits in Blanding’s turtles. That’s right – turtles! Personality has been linked to survivorship in a number of species, and as the DZS is actively involved in conservation efforts with the Blanding’s turtle – a species of special concern in the state of Michigan – we wanted to learn more. Two personality traits emerged from our research: aggressiveness and exploration, with individuals ranging from low to high in either category. We also discovered that a connection exists between these traits and how Blanding’s turtles fare in the wild.

Researchers have been monitoring the population of Blanding’s turtles in Michigan for several years and making efforts to ensure their numbers don’t drop any further. Female Blanding’s turtles typically lay eggs this time of year, and they often travel rather long distances to find suitable nesting grounds. This certainly puts them at risk, especially as road mortality is one of the major threats they face. When baby turtles hatch, they must find their way back to water, which leaves them vulnerable to predation. The DZS became involved in a head-starting program for this species in 2011. This means that eggs are incubated at the Detroit Zoo and the hatchlings are allowed to grow up safely until they reach a certain size, at which point they are released back into the wild.

We used a series of behavioral tests to uncover specific personality traits, including what is often referred to as the mirror test. A mirror is placed in the testing space and the turtle can choose to approach it and to interact with it. As amazing as turtles are, they cannot recognize themselves in a mirror and hence perceive their reflection to be another turtle. By examining their reaction, we definitely saw each turtle as an individual. Some were reluctant to approach, some were uninterested, some were trying to interact gently, and some were very adamant that there was only room for one turtle in the pond!

Once we identified the personality traits, we wanted to understand what links there may be between personality and the turtles’ behavior and survival once released into their natural habitat. Field researchers from the University of Michigan-Flint tracked the turtles post-release for two years and shared their data with us.

Based on our analyses, turtles that demonstrated high exploration had better survival rates than those who scored low in exploration. During the first year, turtles that were more aggressive traveled further from their release site, but over the entire course of the tracking period, turtles that were more exploratory traveled the most. Turtles that were rated as more aggressive and exploratory were found basking more often. Turtles will rest in the sun to help thermoregulate. This helps them to be more energetically efficient, but being exposed may put them at higher risk of predation. The different personalities therefore behave in different ways that amount to a trade-off in risks and benefits.

Finally, all turtles, regardless of personality, showed a distinct preference for areas vegetated with cattails. Given this demonstrated preference, we now know that this type of habitat might really benefit turtles in future releases.

– Stephanie Allard, Ph.D., is the director of animal welfare for the Detroit Zoological Society and oversees the Center for Zoo Animal Welfare.