April 20, 2022
Fernando Nájera, DVM MS PhD
Saint Louis Zoo Canid Conservation Initiative
The Saint Louis Zoo is leading a new Missouri-based project called the Canid Conservation Initiative. This is a collaborative program between the Zoo, Washington University (Living Earth Collaborative) and the Endangered Wolf Center located in Eureka, Missouri.
We are looking to answer ecological and health-related questions about canids – red foxes, gray foxes, and coyotes – as well as bobcats, which live in close association with canids. We are studying where these native Missouri animals live, their health status, and if these animals are suitable indicators of ecosystem health. The project is working in two ecologically distinct study sites: a rural area at the Tyson Research Center near Eureka, and a suburban area at the Saint Louis Zoo WildCare Park, located in north St. Louis County.Top left: red fox; top right: bobcat. Bottom: coyote. These photographs were taken at Tyson Research Center in 2021. Credit: Tyson Research Center.
For researchers to follow and study the local wildlife, they lean on telemetry tracking devices. These devices, which look similar to a dog collar, are placed on the targeted species and use GPS to track their movements. But before we can track the canids, we first have to humanely and safely trap the animals. Based on previous camera trap photos provided by Tyson Research Center researchers, humane cage traps are placed in areas intensively used by the target species and supplied with bait. These traps are built to hold the animal without causing harm or undue stress to the individual. As you might guess, meat is an appealing bait for carnivores! One of the most successful baits has been road-killed deer provided by our partners at the Endangered Wolf Center.
When we have a new animal, we take blood, hair and feces samples of the target species, as well as those they interact with, such as raccoons and opossums. This information helps the researchers understand the health of these wild animals and provides a database of information that may be relevant in years to come in this field.Researchers take biological samples, measurements and perform a physical examination on an opossum under anesthesia. Credit: Saint Louis Zoo Institute for Conservation Medicine
Patience Is Key
This process has taught the team to be patient, as these animals are smart and wary of anything unusual in their environment. It can take many nights before an animal is comfortable enough to walk into the trap for a free meal.
These photos of a red fox (shown below) represent over a month of attempted trapping. As the animal became more and more enticed by the food, it eventually went into the cage trap. We were then able to collect data, add the tracking device and release it back into the wild.Photos of a fox moving around the trap. It took over a month before the team was able to safely capture the fox. Credit: Tyson Research Center.
With over 200 trap-nights into the research project, researchers were able to take samples from 16 opossums, 12 raccoons and a red fox. Excitingly, the Zoo recently was able to sample two bobcats as well!
Sampling the carnivore community at the Tyson Research Center and the Saint Louis Zoo WildCare Park will give researchers the information needed to understand disease exposure in these species, including the possible presence of diseases that are transmitted from animals to humans, called zoonotic diseases.
So far, we have one fox and two bobcats running around the forest of Missouri with GPS devices! As we continue to research in the coming months, we will learn more information about the health and ecology of these amazing creatures that share our habitats with us!
January 24, 2022
Author: Corinne Kozlowski
A fennec fox wearing a collar with a Fitbit activity monitor inside. Credit: Saint Louis Zoo.
Have you ever visited the Zoo and enjoyed a close-up encounter with an animal? If so, you likely interacted with one of the Zoo’s many animal ambassadors. Animal ambassadors are individual animals that help educate the public about their species. Currently, the Saint Louis Zoo does not have these animals interacting with guests. But previously, many species have served as zoo ambassadors, and one of the most popular was the fennec fox, a small fox with long ears and a friendly disposition. Zoo educators utilized fennec foxes to inform visitors about climate change and desert adaptations, and these foxes helped inspire guests to take action in protecting wildlife.
A staff member holds a fennec fox during a guest event at the Saint Louis Zoo. Credit: Saint Louis Zoo.
Zoos have long known that up-close guest interactions with ambassador animals can increase learning about the natural world and help develop positive attitudes about animals and conservation. But, while the benefits of engaging guests with ambassador animals are well established, there is still more to learn about how ambassador programs impact the animals themselves. To address this question, scientists at the Zoo received funding from the Association of Zoos and Aquariums Conservation Grants Fund to determine if fennec foxes participating in ambassador programs showed differences in activity patterns, hormone production, or personality traits. Zoo staff were particularly interested in whether fennec foxes, which are considered nocturnal, would show changes in activity if they participated in programs during the day, similar to a person working a night shift.
We collected data from 36 fennec foxes at three institutions, including the Saint Louis Zoo. Foxes were each fitted with a Fitbit One© activity monitor which was worn in a collar around the foxes necks. Similar to the Fitbits that many people wear to measure movement, these devices are used to measure activity in zoo animals.
Fitbit One® activity monitor worn by fennec foxes.
Zoo staff also collected fecal samples to measure cortisol, a hormone associated with activity, metabolism and sometimes stress. Finally, we assessed the personality of fennec foxes in zoos. Like people, animals can show noticeable differences in personality, from bold to shy, or confident to cautious. We wanted to know whether certain traits might be more common in foxes that routinely interact with zoo staff and guests.
We found that ambassador foxes, like other zoo foxes, were most active around midnight. There was no evidence that ambassador foxes were active earlier in the day, as we had expected, since programs take place during the morning and afternoon.
Activity pattern of a fennec fox at the Saint Louis Zoo. Foxes were most active at night.
The Zoo also found that levels of cortisol were comparable among zoo foxes, but that personality traits differed. Foxes that participated in ambassador programs were more likely to be described as playful, confident, and friendly in comparison to other foxes in our study. This could mean that animals that participate in ambassador programs become more approachable to humans.
Educating our community about wildlife and motivating guests to preserve the natural world are goals of the Zoo. Our results confirm that fennec foxes can serve as ambassadors to help meet these goals without disrupting their normal activity patterns or increasing their stress. This information is invaluable, as it confirms that we can engage our guests with these charismatic animals while meeting our foxes’ behavioral and psychological needs.
This study was conducted before the Zoo’s ambassador programs were put on hold. More details about the Zoo’s study can be found here.
December 26, 2021
Author: Ashley Edes
Animal Welfare Scientist
Guests look at the Humboldt penguins at the Saint Louis Zoo Penguin & Puffin Coast. Credit: Saint Louis Zoo
If you have visited the Saint Louis Zoo, then chances are you’ve been splashed with icy cold water from frolicking penguins at the always-chilly Lichtenstein Penguin Cove at Penguin & Puffin Coast. In the wild, these natural swimmers spend much of their lives in the ocean hunting for food. But in zoos, penguins are well-fed, and without the need to find their next meal, they generally spend less time in the water. Guests are always excited to see penguins swim, whether they are calmly floating or zipping around underneath the surface. From a welfare perspective, animal care teams at the Zoo also like to see the penguins in the pool – as a natural behavior, swimming is a great form of exercise, provides stimulation for the animals, and can improve penguin health.
In a recent Zoo study, the Research Department at the Zoo explored the relationship between guests and penguin activity, specifically swimming. Do guests hinder a penguin’s interest in swimming? Do guests have any effect on this natural behavior? We had good reasons for asking these questions, as we were not the first group to address these topics. As scientists at the Zoo, part of our jobs involves being well-versed in studies published by other researchers that relate to the animals in our care. We were aware of conflicting findings on the effect of people on penguin behavior, including swimming.
For example, a few studies, observing both penguins in the wild and in human care, demonstrate that certain species of penguins, or specific groups of penguins, are sensitive to visitors. These studies showed increased levels of stress-related hormones and avoidance behaviors in the animals when humans were near. However, other studies show the opposite effect, with penguins exhibiting no negative behavioral or hormonal changes. Some studies even show an increase in activity or interest in interacting with visitors! With the considerable variation in results between different species and at different zoos, we decided to conduct our own study investigating how visitors impact swimming behavior in our mixed-species penguin colony at Penguin & Puffin Coast.
A Gentoo penguin swims in front of visitors at the Saint Louis Zoo. The study showed the gentoo penguins engaged in more pool use when crowd sizes were larger, suggesting visitors are a positive stimulus that attracts individuals to the water. Credit: Saint Louis Zoo
Our study was performed remotely using cameras and microphones mounted inside Lichtenstein Penguin Cove where the king, gentoo and southern rockhopper penguins live. We also used the Zoo’s Penguin Webcam that guests can watch from home. Using video and sound recordings from the summer of 2016, we counted how many guests were present, determined the composition of the crowd (i.e., how many guests were adults and how many were children), and measured the noise level. For the penguins, we counted how many of each species were on land versus in the water. During the study period, there were 20 king, 14 gentoo, and 24 southern rockhopper penguins living at Penguin & Puffin Coast – all 58 penguins had to be counted each time data were collected, which was 2,545 times!
King penguins at the Zoo. This study found guests are likely a neutral stimulus to this species. Credit: Saint Louis Zoo
So, what did we discover about our tuxedo-clad swimmers? Each species showed different results in this study, which was expected as we know some species and individuals are more gregarious than others. Regarding the king penguins: crowd size, composition and noise levels did not impact swimming behavior, indicating visitors are likely a neutral stimulus to this species. However, the gentoo penguins engaged in more pool use when crowd sizes were larger, suggesting visitors are a positive stimulus that attract individuals to the water (where they can be closer to people). Guests also may promote swimming behavior in the southern rockhopper penguins, for which we saw increased pool use with louder crowds.
Visitors may promote swimming behavior in the southern rockhopper penguins. Credit: Saint Louis Zoo
Overall, these results are encouraging! They tell us that visitors do not inhibit pool use and that some of our penguins actually swim more when guests are visiting. This suggests some penguins find humans to be a source of enrichment, which is great news, since guests are able to walk right up to the edge of the pool and experience the penguins up close. It is important to note, there is plenty of space for penguins to move away from our guests, and the habitat is designed so that the animals may choose to either be close to people or stay away, either on land or in the water. The Zoo also has a staff member inside the building at all times who makes sure visitors don’t touch or feed the birds. This helps ensure our birds feel safe in expressing their interest in humans by approaching guests and performing their natural behaviors when visitors are nearby.
This study and similar efforts are one way the Zoo works to provide positive welfare for all the animals in our care. In this instance, we found that the penguins are able to perform swimming behaviors that are important to them at their leisure because they are not trying to avoid visitors. This promotes natural activity patterns, better health and a positive emotional state, all of which are critical to good welfare. So, the next time you are at the Zoo, don’t be shy! Guests should be sure to stop by Penguin & Puffin Coast and say hello to the penguins!
This study was published in a special issue of the journal Animal Behavior and Cognition focused on animal-visitor interactions.
Click here to read the full paper.