Humans aren’t the only ones who enjoy cozying up inside when the fall chill takes over — so do some of the animals who call the Detroit Zoo home!
If you are visiting the Zoo this season, you may notice that Suka, a female polar bear, has not been as visible inside the Arctic Ring of Life habitat. But there’s no need to worry, her absence is for a heartwarming reason. This fall and winter, Suka will be nestled in her cozy den behind the scenes in hopes of welcoming a polar bear cub (or two!) into the world.
Last spring, Suka and her male counterpart, Nuka, were observed engaging in an important act of nature — breeding. This pair has successfully mated in the past, resulting in twins Astra and Laerke, who were born in 2020 and moved to the Point Defiance Zoo and Aquarium in June 2023. After their past success, experts with the Association of Zoos and Aquariums — an organization dedicated to animal well-being, conservation and the sustainable management of animal populations in human care — recommended that Suka and Nuka be paired together again. So far, all seems to be going well.
Suka and Nuka
It’s important to note that female polar bears will den whether or not they are pregnant. While we are hopeful Suka and Nuka’s union was successful, unfortunately, our staff has no way to confirm if Suka is indeed pregnant. Polar bear pregnancy tests don’t exist, and polar bear cubs are so tiny in the womb that they cannot be seen via ultrasound. Instead, our dedicated animal care team will be closely monitoring Suka for any subtle signs that might indicate an impending birth. We won’t know for sure if there are cubs on the way until November or December.
To give this momma bear the best chance of success, Suka must remain undisturbed during her denning period. Denning is a critical phase in the life of a pregnant polar bear, where she seeks seclusion and tranquility to give birth and raise her cubs. Zoo staff is committed to providing Suka with a stress-free environment to ensure her comfort and well-being. Our team is hopeful that Suka will emerge from this denning season as the mother of some new cubs!
While Suka is cozied up in the bear den these next few months, visitors are encouraged to drop by and say “hi” to Nuka and the sea otters who call the Arctic Ring of Life home. And don’t forget to send Suka all your well wishes.
Update as of January 2024: After months of rest and relaxation under the careful monitoring of our animal care team, Suka emerged from her den. Though we were hopeful for cubs, this was not the case. Suka is now acclimating to life outside the den and will not always be in sight. The team will monitor her closely to determine when she is ready to be reintroduced to male polar bear Nuka. We look forward to a winter full of polar bear fun with Suka and Nuka!
Suka with her past cub, Astra, who was born in 2020.
Leah Seldon created an educational video about wolverines during her internship for the Detroit Zoological Society.
By Leah Seldon, high school intern for The Detroit Zoological Society (DZS).
It was a Monday morning, and instead of making a right to go to school, my father kept straight on a path we hadn’t taken before. It was the first day of my Senior May Project (a program where seniors at my school do a three-week internship in place of attending classes), and I felt everything: nerves, sleepiness and excitement with no idea of what to expect on my first day. Luckily, I was met with smiling faces and people eager to assist me in finding my way. To give some context, I decided to intern for the DZS because the Detroit Zoo was always a place of fun for me. So, when I heard students in the year ahead of me interned there, I decided I would too. Before my first day, I virtually met with my supervisors to go over how my interests would fit within the education department’s needs. Together, we decided I would produce a video as an independent project. What type? That, we were unaware of.
I spent tons of time exploring and learning during my first week. Through a tour of the Zoo, I was introduced to all the animals as I walked past each of their habitats. I shadowed Learning Labs, programs where a member of the education staff teaches a group of students on a specific animal-related topic. During those times, I observed teaching methods that encouraged student engagement to enhance the learning process. It was a technique I had not seen used often. Also, I read a book and learned about humane education, which taught me the importance of teaching children to be kind to everything and everyone and to be aware of their choices. During my first education staff meeting, it was mentioned that the Zoo was working towards creating an experience for people to recognize the animals as living beings and not just as objects of beauty to admire. It was that piece of information from the meeting that I took with me when I went on to create my video. I wanted to help people connect with an animal.
Yaro and Janis caught Leah’s attention during her internship.
As part of my first project, I learned about the DZS’s conservation efforts with the creation of a script for a CARE Grant. My goal was to create a script that highlighted how a specific CARE Grant was to fund a trip that would encourage teens to get involved in the conservation of amphibians. Through my research, I was introduced to Species Survival Plans. I learned how the DZS partnered with other zoos to increase the population of certain amphibian species through breeding, releasing into the wild and research. I used my newfound knowledge to help me craft a script for the CARE Grant program. With the completion of this script draft, I was able to work more on my independent project.
Something I can’t fully explain drew me to the wolverine habitat each day, which wolverines Yaro and Janis call home. Maybe my dog’s name Wolverine made me biased, but it was much more than that. They ran around so freely. They kept me wondering what they were going to do next. I found myself watching them, being mesmerized and going into a trance. They constantly kept my attention day after day. They became my favorite animal in the Zoo.
In the middle of my second week, it came time for me to decide on an independent project. I knew I wanted the wolverines to be the focus of the video I was to create after watching them for so long. I started brainstorming and realized that I wanted to create something directed toward children because I find it very important to educate youth. This required me to get into the mind of a child. Luckily, I was one not very long ago. I remember that my favorite way of learning was when cartoon animals taught me. They were always more fun, and they were cool to look at. Also, I felt close to them because they were characters I could relate to. Therefore, I decided to create a video that gave information about wolverines from a wolverine… plush.
The wolverines enjoy exploring their habitat at the Detroit Zoo.
After mentioning this idea to one of my supervisors, they informed me of anthropomorphism.
This term was unknown to me, but after a conversation with them, I learned the importance of it. Anthropomorphism is when human characteristics are attributed to an animal. During our conversation, we brainstormed a list of the pros and cons of anthropomorphism. There were ways of using it that would create harm and ways that would be beneficial. It was important to me that I was careful with my usage of anthropomorphism to not unintentionally misrepresent the wolverine species. After navigating this new term, I was ready to make a video focused on wolverines. I didn’t stop there, though.
When thinking of creating this video, I wanted to include the wolverines who initially captivated my attention, Yaro and Janis. I wanted the viewer to watch the video and learn more about individual wolverines. That was a lesson the education staff taught me 𑁋 to focus on the species but also highlight the individual. As I went out into the Zoo each day, I saw that happening. There were conservation plans put in place for the protection of specific species. Also, each animal was cared for, and their needs were met. Each animal had a tailored diet, enrichment items and the appropriate habitat. I could tell they were each given the attention they deserved. That prompted me to include a segment in my video that focused on Yaro and Janis to give them their spotlight.
Creating this video has been a process of love. I am truly grateful to the entire education and volunteer services teams for taking me in and teaching me. They taught me that being part of a team makes everything better. Reaching out to call on others for support is okay and at times necessary. They also showed me that it takes drive and true dedication to be involved with such important work. Before coming here, I was unaware that the DZS was involved in so much, including humane education, animal well-being and conservation. I had no idea that such a pillar in all these topics lived so close to me.
By Mary Humbyrd, coordinator of behavioral husbandry for the Detroit Zoological Society (DZS)
National Zoo Keeper Week starts annually on the third Sunday of July. Representative Susan A. Davis introduced House Resolution 509 on June 21, 2007. This resolution was proposed to encourage individuals on a national level to engage in programs, activities and ceremonies during National Zoo Keeper Week that encourage species conservation and public awareness of the important role of zoos in wildlife conservation.
It is an absolute honor to celebrate our DZS zookeepers. Zookeepers are a unique bunch and have many amazing talents not often seen by zoo guests. Our animal care team is creative, innovative and can build just about anything with some zip ties and duct tape. Zookeepers brave the hottest days of summer and the freezing days of winter. Animal care specialists are on a constant quest for knowledge to improve and raise the bar to provide the best care of the animals they adore. They are involved with the animals from birth to passing and build lifelong relationships. They have their heart and soul in the profession. Zookeepers are advocates, educators, scientists and enjoy sharing their passion with anyone and everyone they encounter. As no day is ever the same, zookeepers have an incredible ability to go with the flow — but with precision and accuracy. Their passion for all living things is inspiring and enlightens all of us who have the privilege of hearing their stories.
From ice cream socials and cookouts to food trucks and Tigers games, scroll through the gallery below to see how we celebrated the DZS animal care team this past National Zoo Keeper Week!
Isa (right) is certainly aware of guests – but how do they make her feel?
Authored by Julia King, external researcher from Hunter College.
The Detroit Zoo’s Australian Outback Adventure is a favorite among Zoo guests for good reason – you can follow a designated path through the habitat and view 11 red kangaroos and two red-necked wallabies without any barriers! Although the opportunity to cross paths and appreciate these marvelous marsupials up close is an exciting draw for Zoo guests, it begs the question: how do the kangaroos feel about having people in their home?
My name is Julia King, I am a graduate student in Hunter College’s Animal Behavior and Conservation program, and I set out to answer this question in an investigation of kangaroo well-being.
Animal well-being refers to the overall quality of an animal’s physical, mental and emotional health. Well-being can range on a continuum from great to poor and can vary over time and across individuals. Just as no two people are the same, no two animals are the same, and therefore do not have the same well-being. Two individual animals of the same species housed in the same environment may respond to the same stimuli in different ways – one kangaroo may be intrigued by a foreign object in their habitat, while another may be fearful of the same object. Because of this, well-being is best assessed at an individual level.
Julia King places a foraging ball in the kangaroos’ favorite spot.
The Detroit Zoological Society (DZS) strives to ensure all its resident animals have great well-being and are thriving. The unique design of walk-though habitats begs the question: how does the presence of people in the habitat affect the kangaroos? Wild kangaroos may perceive humans as threats and respond fearfully, so it is possible that captive kangaroos may feel similarly. Studies on zoo-living kangaroos, both at the Detroit Zoo and elsewhere, have looked at kangaroo behavior, levels of hormones related to the stress response and habitat use in response to visitor presence. These studies have shown that kangaroos may restrict their spatial use (i.e., use less of their habitat) with higher numbers of visitors in their habitat. However, there are no direct links to suggest visitors are a source of stress for inhabitants of walk-through marsupial habitats.
With the help of DZS animal welfare and mammal staff, I designed a scientific study to see whether the presence of guests inside the kangaroo habitat would have an impact on the kangaroos’ emotional well-being. The idea is simple: give them treats and make them work for it! Like people, animals may be willing to work harder for a reward when they are in a positive headspace and less so when they’re experiencing negative emotions. The kangaroos were offered yummy treats (wheat grass and willow clippings) in feeders with varying levels of difficulty, and the interactions with these treats were analyzed with respect to visitor number. If the kangaroos experience negative emotions when more guests are present, they should be less willing to work for food. Therefore, I predicted that the kangaroos would not work as hard for treats when there were more people present in their habitat.
To make the treats more difficult to access, I used location and a foraging ball challenge feeder. Going to an unusual or avoided area or manipulating a foraging ball to get treats requires more work than eating treats directly off the ground in your favorite place – it’s harder to get ice cream from a shop than from your freezer, and harder still when you must pull it out of a box and unwrap it. Treats were placed out in the kangaroos’ favorite spot, either directly on the ground or hidden within the foraging ball. Treats were also placed in a location in the habitat that kangaroos used less frequently, again either directly on the ground or within the foraging ball.
Many kangaroos seemed to enjoy engaging with and obtaining treats from the foraging ball.
What happened? As you might expect, the kangaroos were much more likely to eat the treats placed in their favorite spot, while they rarely ventured to the less favored area. There were also no observed effects of visitor presence, meaning, the number of people in the habitat did not influence when and where the kangaroos were willing to get the treats. This may be because at the time of the study, which took place November to December 2021, there were very few guests present in general. Or it may be because many of the kangaroos were born and raised at the Detroit Zoo, and they are used to seeing people on the guest pathway in their enclosure.
An unexpected result from this study was that the kangaroos were far more likely to eat the treats when they were hidden inside the foraging ball than presented freely on the ground. This may seem counterintuitive at first – why would you prefer to unbox and unwrap ice cream when you can just eat it right out of the carton? But it turns out that many captive animals may prefer to work for food even if they don’t have to. This well-documented phenomenon is called contra-freeloading, and it is the basis for many foraging enrichment designs. Environmental enrichment is just that—something that benefits a captive animals’ daily life, usually by eliciting natural behaviors. Food is never free in the wild. By providing an additional challenge like a foraging ball, eating becomes much more interactive and mimics some of the challenges associated with foraging in the wild. Working for food provides mental stimulation and a sense of accomplishment, promoting positive well-being in captive animals.
This study brings some good news to the Detroit Zoo, the kangaroos and all the people who love to visit them. First, the kangaroos do not show any negative responses to the people in their habitat, confirming the results of an earlier study at the Detroit Zoo. Second, we may have inadvertently found a fun and easy way to add some enjoyment and fulfillment to these kangaroos’ lives!
Authored by Erica Graber, snail care specialist at the Detroit Zoological Society.
On April 15, 2,413 total partula nodosa snails were released into Papahue Valley, Tahiti, making this the largest wild release that has ever happened for this species. Partula nodosa, also known as Polynesian tree snails, are considered extinct in the wild by the International Union for Conservation of Nature —making this record-breaking release extremely important.
Of the 2,413 partula nodosa released, 1,449 were from our collection at the Detroit Zoo! In November 2022, we sent 1,500 snails to the St. Louis Zoo in preparation for this release. From there, we shipped the snails to Tahiti in early April. Once they arrived in Tahiti, they were all marked with UV reflective paint, making them more visible on the trees and easier to track during post-release checks — even in the dark. They were placed in slow-release containers so they could leave and head up to the tree canopies at their own pace.
The Detroit Zoo released 1,500 snails to restore populations abroad.
Multiple partula snail species were driven to near extinction after African giant land snails were introduced to the islands as a food source for the people living there. Unfortunately, the African giant land snails escaped and thrived in the island habitat, causing them to quickly become invasive and destroy the vegetation, wreaking havoc on the island’s fragile ecosystem. Predatory rosy wolf snails were introduced as biological control, which backfired when they only went after native snail species, including partula snails. Partula snails are vital to maintaining tropical forest health as they eat decaying plant matter and fungi and recycle those nutrients into the soil. They are also an important part of Polynesian culture, as their shells were used in ceremonial jewelry and the decorations of the indigenous islanders. Losing this species is devastating both to the balance of the forest ecosystem and the history of the people living there.
At the Detroit Zoo, we have a room dedicated to our snails. As of May 23, we have 41 Kritter Keepers housing 3,595 snails. Each tank has paper towel as substrate, a feed tray, a cuttlebone and a fake plant to hide and climb on. The food is a mixture of organic nettle powder, ground organic oats, ground trout chow, a powdered calcium supplement and Teklad snail stress powder. When ready to use, we mix it with water to create a paste that we spread across the feed tray for the snails to easily eat. We keep the humidity in the room between 60 and 80 percent, and the temperature is consistently at 68 to 72 degrees Fahrenheit. To keep the humidity up, which can be challenging in the dry winter months, up to five humidifiers run at once. We also mist the tanks daily to keep the paper towel moist.
The snail room at the Detroit Zoo keeps the animals in optimal conditions.
As this species is extinct in the wild, we must track how many snails are in our captive population. Every month, I count all the snails and separate them based on size — newborn, juvenile, sub-adult and adult. Newborns are tiny, less than 3 millimeters. Juveniles are between 3 and 7 millimeters. Sub-adults and adults are similar in size, more than 8 millimeters, but the adults are most distinguishable by the thick white “lip” around the shell opening.
As a result of all these conditions being just right, Detroit Zoo team has been able to consistently breed this rare snail and contribute to the reintroduction process. The recent release of 1,500 snails was record-breaking for our facility — our previous record was 100 snails in May 2015.
Our captive population is still flourishing and growing. There is talk of doing releases more frequently — as soon as September! With the commitment of Detroit, St. Louis, Akron, Woodland Park, Disney’s Animal Kingdom and all the other facilities working together to protect this species, the future is looking big and bright for these little snails.
Erica Graber helps organize this project at the Detroit Zoo.
You don’t need to head up north or plan a camping trip to connect with nature – there are amazing animals all around us! Let us introduce you to three of your wild neighbors.
They call it mudpuppy love!
Mudpuppies are the second-largest salamander in the western hemisphere. These amphibians may not give off total puppy-dog vibes, but when you see them up-close and in-person, you can’t help but to fall for their charms. There is even a whole celebration in their honor called Mudpuppypalooza taking place March 26 at the Belle Isle Nature Center!
Mudpuppies have wide faces and frilly, external gills on the sides of their heads that act like filters in the water. This means they need to live in clean water to stay healthy. These pups spend most of their time under the cover of flat rocks or slabs of concrete at the bottom of rivers – including our very own Detroit River. They are an important part of Michigan’s aquatic ecosystem, and the Detroit Zoological Society has been collecting data on mudpuppies and water quality in the Detroit River since 2004. Learn more about our monitoring efforts.
Say hi to Michigan’s largest snake!
Black rat snakes can grow to be an impressive 8 feet long – but don’t worry, they are non-venomous and harmless to humans. Rodents, however, are not so lucky. As their name suggests, this species hunts rats and will often enter barns or abandoned buildings in search of food. They use the constriction method of hunting and consume their prey in a single bite! Rat snakes can also be found hiding in tall grasses, under fallen trees or in hallowed out logs, just like our friend here, who just emerging after a taking a nice afternoon nap. The habitats at the Belle Isle Nature Center are designed to mirror the landscape the species might experience in the wild – do any of the elements look familiar to you?
Do I spot a spotted turtle?
If you have visited our Nature Center before, you may be familiar with our turtle pond. This expansive indoor habitat is home to several turtle species, including this pair of spotted turtles. They may be smaller than most of their pond mates, but as you can see from this video, they make up for it in moxie! Spotted turtles can be found in bogs, marshes, swamps, ponds and woodland streams throughout Michigan. They can often be seen basking in the midday sun, but when surprised, spotted turtles will dive underwater and completely bury themselves in the mud. They also retreat to these muddy beds to stay cool on hot summer days. Spotted turtles in Michigan are threatened by habitat loss and from being removed from the wild by reptile collectors. That brings us to a rule that applies to all wild animals – look don’t touch! This is the best way to keep your new friend safe.
The Belle Isle Nature Center is all about making connections. People, animals, natural and unnatural landscapes are all a part of the unique tapestry that is Detroit. Visit belleislenaturecenter.detroitzoo.org to plan your visit. The Nature Center is open every day from 10 a.m. to 5 p.m. and and is always free!
Winter Nature Camp recently took place at the Belle Isle Nature Center.
Authored by Luke Grange, senior education specialist at the Belle Isle Nature Center.
“Can we write on this?”
The campers looked hopefully at the butcher paper-covered tables and cups of markers. When they were told that indeed the markers were for drawing on the tables, they happily got to work drawing, signing their names and making their mark.
This was the scene at the Belle Isle Nature Center’s Winter Nature Camp on Jan. 3. Those campers had just arrived at the Nature Center’s first camp since 2019. The campers didn’t seem to mind the layoff as they drew rainbows, birds and the odd video game character as they got to know one another before breaking up into age groups to go explore outside.
The Belle Isle Nature Center’s habitats and interactive exhibits celebrate places in the city where you can connect with the natural world. Similarly, campers experienced both the natural and man-made portions of Belle Isle ― walking on top of deer prints and under willow trees to explore the rarely seen inside of a covered footbridge. Fire hydrants poked up from alongside the trails like steel mushrooms as raptors flew overhead.
Campers loved building their beginner birding skills at Winter Nature Camp. Brittany Leick, program coordinator of the Detroit Audubon, assisted Winter Nature campers in learning to identify seven local, colorful birds and then practicing how to use binoculars. Campers also visited the bird viewing window and learned about the ultraviolet patterns inside the glass that the Belle Isle Nature Center installed to help make the windows bird safe. Campers then got to paint their own bird shapes to put on their windows at home.
The new Belle Isle Nature Center was thoroughly enjoyed by campers. Children visited the young learner’s space to act as ants and move giant seeds and dirt throughout the tunnels. They experienced life in the pollinator hallway as a bumblebee, seeing the normally invisible UV patterns that flowers advertise to insects. Each day, the campers would find something new to do in the space.
At the end of the week, campers were asked to draw their favorite camp activities. Almost everyone mentioned spending time out in nature with the new friends they made. As they had made their mark on the tables over the course of the week, adding to their drawings with each meal and snack, campers had made their own mark with the friendships they had formed.
Registration for Winter Nature Camp was done through community partners in Detroit. A waiting list was used for any remaining spots. Summer Nature Camp enrollment will happen the same way and is coming soon! Stay connected with the Belle Isle Nature Center website for updates.
The Belle Isle Nature Center is located at 176 Lakeside Dr., Detroit.
Stay tuned to the Belle Isle Nature Center’s website for more camp opportunities!
Authored by Dr. Kylen N. Gartland, manager of applied animal welfare science for the Detroit Zoological Society (DZS).
Making a happy home requires an abundance of care, creativity and finesse – especially when that home is for gorillas!
The Detroit Zoo’s Great Apes of Harambee habitat is home to three adult male gorillas, Chipua (Chip), Kong-Mbeli (Kongo) and Pendeka (Pende). You may notice something unique about this group – there are no females! Chip, Kongo and Pende are part of a bachelor group. Although gorilla family groups are generally composed of one adult male, multiple adult females and their juvenile offspring, gorillas may also form bachelor groups composed of multiple young and maturing male gorillas. These bachelor groups provide individuals with opportunities for a healthy social environment with companions with whom to form complex and lasting relationships.
Forming a successful bachelor group is no small feat. Zoo staff and managers must consider a plethora of variables such as age, personality and family history. Although many all-male gorilla groups are formed when the individuals are juveniles, the relationships and dynamics within the group may undergo any number of changes as individuals grow and mature. The ideal management strategy for a group of 10-year-old gorillas can look very different from that for a group of 20-year-olds. What’s more, gorillas develop unique personalities and preferences, just like humans! Plans for long-term care and well-being must integrate not only group needs but individual factors as well.
Chip, Kongo and Pende have been a cohesive social unit for more than 20 years, due in large part to the excellent care provided by the Detroit Zoological Society team! Zoo staff are always on the lookout for new information that can help us manage the complex inter-relationship between time, group-level needs and individual-level preferences that leads to a happy, healthy home.
One way animal care staff can ensure the gorillas are living in optimal conditions is through tools such as Qualitative Behavioral Assessments (QBAs). QBAs are keeper rating tools that allow expert care staff to evaluate the well-being of a given animal based on subtle cues like movement, posture, dynamic expressions, and individualistic indicators of emotional states. Using QBAs, care staff and welfare scientists can collaboratively explore new and innovative strategies for maximizing animal well-being.
Recent nationwide work between members of the DZS’s Center for Zoo and Aquarium Animal Welfare and Ethics (CZAAWE) and experts at other zoos accredited by the Association of Zoos and Aquariums (AZA) created opportunities to investigate overnight housing. This work suggested that groups of younger gorillas may thrive with the constant access to group members provided by social overnight housing, while groups with more mature gorillas may benefit from the space and solitude provided by individual overnight housing. Judging what is right for each individual and each group is an ever-evolving challenge, as an individual’s well-being varies over time. The gorillas at the Detroit Zoo provided a unique opportunity to investigate overnight housing, as the group has historically been managed on a rotation with three nights spent together socially and the fourth night spent solitarily.
To make this investigation possible, CZAAWE staff members came together with mammal supervisor Melissa Thueme and other members of the primate care team to create and validate a QBA tool just for gorillas! This tool, called the Gorilla Behavioral Assessment Tool (GBAT), combined CZAAWE staff’s scientific training with the primate care team’s gorilla expertise. Using the GBAT, primate care staff conducted three months of daily evaluations of Chip, Pende and Kongo from June to August 2022. Once the primate team had collected the data, it was time for CZAAWE to step in! CZAAWE staff used statistics to analyze the data from the GBAT evaluations to look at differences between the overnight housing conditions.
With a lot of input from the diverse supporting departments — and more than a little math — staff concluded that the gorillas generally demonstrated increased welfare from being housed separately overnight as compared to being housed socially. Individuals were more curious, less anxious and less aggressive with other gorillas! With these data in hand, the primate care team transitioned to housing the gorillas separately every night.
The DZS is proud to invest in studies like these that support care staff in making the best possible management decisions and offer opportunities for cross-departmental collaborations. With the support of four other AZA-accredited zoos, we have set out to establish the GBAT as a reliable and useful tool for zoos across the United States and beyond! Stay tuned for more exciting updates as we continue this study.
The Wyoming toad was once found in abundance in the Laramie River Basin. However, catastrophic population declines were observed throughout the 1970s. By 1983, the Wyoming toad was thought to be extinct. Biologists could make no clear determination for the cause of the decline.
With a bit of luck, a small population of about 20 animals was rediscovered in 1987 at Mortenson Lake, bringing hope that the species could be saved. Rescuing the species by bringing it into captivity was the only option to avoid extinction.
Amphibian Chytrid Fungus and Preventing Amphibian Extinctions
Throughout the 1980s and 1990s, amphibian declines were common around the globe – something that puzzled biologists. At the time, there was no obvious answer as to why multiple amphibian species were rapidly disappearing in Australia, Central America and the United States. In 1998, the amphibian chytrid fungus – a microscopic primitive fungi – was discovered to be the cause of disease resulting in these declines. Biologists have attributed the amphibian chytrid fungus to be the primary cause of approximately 100 amphibian extinctions and to have impacted more than 700 amphibian species. No other wildlife disease has impacted biodiversity as much as this fungus.
The Wyoming toad is highly susceptible to the amphibian chytrid fungus. The National Amphibian Conservation Center at the Detroit Zoo was built in part as a response to the amphibian biodiversity crisis, which assisted in keeping some of the most imperiled species away from the edge of extinction. The Wyoming toads at Detroit Zoo live in a biosecure room, which keeps them safe from being potentially exposed to the disease!
Ex-situ rescue, which is when a species is brought out of the wild into captivity for conservation, is a last resort. Unfortunately, we are often left with no other options. Rescuing a species in captivity requires intensive management to maintain the population, and it’s a long-term commitment by a dedicated and passionate team.
Wyoming Toads at the DZS
The DZS was an early partner in rescuing Wyoming toads, welcoming our first toads in 1995. A Species Survival Program (SSP) was also formed in 1996 to organize efforts among zoo partners and the U.S. Fish and Wildlife Service. The amphibian team at the DZS has produced 10,730 Wyoming toad tadpoles, toadlets and adults for reintroduction since joining the program in 2001! These animals are bred at the DZS and later sent to Wyoming to be released into the wild. The Center for Zoo and Aquarium Animal Welfare and Ethics at the Detroit Zoo has also led studies that have helped improve the husbandry of Wyoming toads in captivity by comparing the preferences for substrate, which improves our care for this very important species.
Caring for Wyoming Toads at the Detroit Zoo
Mike Andrus is the primary colleague who takes care of the Wyoming toads at the DZS, and his years of experience in the amphibian department caring for these toads is one of the keys to Detroit Zoo’s success. Mike handles more than 30 toads at the Zoo
Mike Andrus is the primary colleague who takes care of the Wyoming toads at the DZS, and his years of experience in the amphibian department caring for these toads is one of the keys to Detroit Zoo’s success. Mike handles more than 30 toads at the Zoo, where he carefully cycles the temperature throughout the year, including when he places the toads in a refrigerator to hibernate. This process requires a lot of fine-tuning and experience – and prepares the toads, which are each equipped with their own individual ID to track genetics, for breeding.
Mike Andrus holds a Wyoming toad in the biosecure room.
Wyoming toad tadpole reintroductions
In June 2022, Mike traveled to Laramie, Wyoming to participate in the reintroduction of Wyoming toad tadpoles. Several thousand tadpoles were sent from SSP partners for reintroductions. It was a busy day, as tadpoles were placed in bags of about 100 animals and methodically distributed around reintroduction sites.
Tadpole reintroductions are very important to continue supporting the recruitment of new toads into the population. In the months following the tadpole reintroductions, hundreds of recently meta morphed toads are found — each one with the potential to make it to adulthood and breed in the wild.
Bags of tadpoles produced by zoos around the country and U.S. Fish and Wildlife Service acclimate before reintroduction.
Wyoming toad surveys
In August 2022, I participated in the Wyoming toad field surveys and an annual SSP meeting. The team was successful in finding many young toads, likely from tadpole reintroductions and some wild breeding. The most exciting part was finding more than 15 breeding-sized adults! Some of the toads had a small identification tag, demonstrating that reintroduced juveniles and adults from captivity are surviving in the wild.
Wyoming toads were found at all four field sites the team visited, a very good sign for a species that was once thought to be on the verge of extinction. Currently, there is no method to mitigate the amphibian chytrid fungus in the wild, but in recent years there are an increasing number of rediscoveries of species once thought to be extinct and vulnerable species persisting in the presence of chytrid.
We’re optimistic that the Wyoming toad will soon hop back from extinction!
A toad reintroduced months beforehand was found during our surveys and appeared in good health. Adult toads receive a tiny tag, much like a micro-chip for a cat or dog, that let us know who they are when they are found in the wild!
Thank you to our SSP partners, who make saving this species possible:
Throughout spring migration, the Detroit Zoo’s 125 acres provided refuge to many weary travelers. Now that the season is coming to a close, our staff is looking back at all the feathered friends who used our grounds as a stop on their journeys.
Over the last couple months, Detroit Zoological Society (DZS) team members have spent many hours surveying what bird species have been utilizing the habitats here at the Detroit Zoo. Some of these species live here year-round, while many species have shown up during migration and will spend the summer here breeding on Zoo grounds. Additionally, several species have used the Zoo to rest or refuel for a matter of hours or days on a long journey home to their breeding grounds.
We have seen and heard many species of songbirds, black-crowned night herons, a redhead, spotted sandpipers and much more! From March until the end of May, we accumulated at least 93 species on Zoo grounds.
Canada warbler
The incredible journeys these brave travelers make every year are hard to put into words. Many winter as far south as Central or South America and may head far north of us into the Upper Peninsula or northern Canada to breed. The blackpoll warbler is one of these extraordinary migrants who recharged at the Zoo this May. This tiny, insectivorous species only weighs around 11 grams and sings a very high-pitched song. They often travel more than 10,000 miles round trip — including an Atlantic Ocean crossing — as they head back and forth from South America to northern Canada and Alaska.
Migrating birds overcome extreme challenges when heading back and forth between breeding and wintering grounds. Besides exhaustion and native predators, there are many human-made challenges. Fragmented habitats, light pollution, domestic cats and windows are just some of the man-made threats that make migration even harder. Here at the Detroit Zoo, we are proud to provide these birds an excellent, protected habitat on their perilous journeys.
Detroit Zoological Society Blog 