Wildlife Conservation: Breeding Eastern Tiger Salamanders

Amphibian breeding season is here! That means it’s time to start helping amphibians get in the mood for love and romance.

The Institution of Museum and Library Sciences (IMLS) recently awarded a $500,000 National Leadership Grant for the purpose of improving reproduction within captive assurance colonies of imperiled salamanders. The Detroit Zoological Society is one of the primary partners on this grant. My doctoral research focused on salamanders, their reproductive physiology and techniques to help them breed, and that very research was the basis for the recent IMLS grant proposal.

Other partners on the grant include Mississippi State University and Omaha’s Henry Doorly Zoo and Aquarium. Now that the grant was awarded, techniques must be taught to the other partners so we can all work together in salamander conservation efforts. I recently visited Mississippi State University in order to train the other principal investigators and the graduate students involved on this salamander grant in principles of natural salamander reproduction and performing assisted reproduction techniques with salamanders.

The training session involved eastern tiger salamanders (Ambystoma tigrinum), which are regionally threatened and endangered in various areas of North America. Like many species of salamanders, the tiger salamander is very difficult to breed in human care. Similar to other species in the “mole salamander” family, tiger salamanders respond to changes in air pressure and temperature when seasonal rain storms occur. These storms are what cue breeding behavior and are very difficult to replicate in human care. Without the ability to provide the appropriate “mood”, tiger salamanders in human care will not often feel romantically inclined. Natural breeding is always the first goal when breeding animals for conservation, but sometimes this is extremely challenging. In these cases, we use alternative techniques while we perfect replicating the natural breeding environment.

In vitro fertilization is a technique used to assist salamanders and other amphibians in breeding. Most salamander species undergo internal fertilization, in which the female picks up a capsule of male sperm, called a spermatophore, which the male has deposited into the environment. The female holds the sperm in an internal pouch that she later empties over her eggs as the eggs are laid. In in vitro fertilization of salamanders, sperm is collected from males by giving them a massage. Eggs are then collected from the female into a small dish where sperm is placed on top of the eggs. Just add water, and presto, you have salamander babies. Of course, it is never just that easy, but the concept is straightforward.

I trained the other primary investigators and students in other techniques as well, including cryopreservation – or freezing and long-term storage – of salamander sperm and sperm quality assessment. The training was very successful, with nearly 100 tiger salamander babies produced. Now the trainees can go on to teach more amphibian conservationists, and we can save more species by assisting with breeding!

– Dr. Ruth Marcec is the director of the National Amphibian Conservation Center at the Detroit Zoo.

Animal Welfare: A Compassionate Approach to Toad Conservation

Staff members from the Detroit Zoological Society’s (DZS) National Amphibian Conservation Center and Center for Zoo and Aquarium Animal Welfare and Ethics are collaborating to find out what toads like. By doing so, we can ensure we are providing for their welfare while they’re in our care and also contributing to the conservation of this species in the wild.

Wyoming toads (Anaxyrus baxteri), also known as Baxter’s toads, are considered extinct in the wild, and their numbers must be bolstered each year by reintroductions of individuals born and reared in the care of humans. They can be found in two locations within the Laramie Basin in Wyoming, thanks to efforts by the U.S. Fish and Wildlife Service and other dedicated organizations including the Detroit Zoological Society.

Wyoming toads were abundant until the 1970s when their numbers began to plummet due to the spraying of aerial pesticides, habitat alteration and the fungal infection caused by chytridiomycosis, which is decimating amphibian populations worldwide. By 1984, the species was listed as endangered and in 1993, that listing changed to extinct in the wild. That year, what were believed to be the last 10 remaining Wyoming toads were brought into a facility to safeguard them and begin a breeding program in the hopes of one day reestablishing the species in the wild.

The Association of Zoos & Aquariums started an official Species Survival Plan for the Wyoming toad in 1996, a program in which the DZS has been very active, including releasing thousands of toads hatched at the Detroit Zoo since 2001. Through the efforts of this collaborative breeding program, more than 1,500 Wyoming toads are currently believed to live in the wild.

Because breeding success continues to be a great concern for this species, the Wyoming Toad Species Survival Plan established strict guidelines for habitat setup at the participating institutions. The habitats are rather sterile to reduce the potential development of any disease processes and consist of a dry area typically made of PVC, a water feature, a basking lamp and a shelter. This type of setup was necessary to properly monitor conditions to promote higher survival rate and breeding success. Due to the success of the reintroduction program, new habitat parameters can be explored, providing the toads with a more stimulating environment.

It is important that we assess how this affects the toads and what preferences they might have. To that end, habitats are being created that provide the toads with a choice between the standard habitat and one that has more naturalistic elements, such as soft substrates, multiple shelters and water features of varying shapes and sizes. With the assistance of our current resident, Emilie Gupta, we will be studying the toads to determine if this choice is important to them. Providing animals with choices and agency – or control – over certain aspects of their lives has been proven to positively affect welfare in some animals. This research will augment what we know about amphibian well-being and will add a compassionate dimension to this conservation success story, in which ensuring the welfare of individuals is a critical part of protecting the species.

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: Mitigating Human-Bear Conflicts in Armenia

Armenia is a small country in the south Caucasus Mountains of west Asia between the Black and Caspian seas. Despite its size, Armenia is a hotspot for biodiversity and important for wildlife conservation because of its location at an intersection where wildlife converge from Eurasia, Africa and the Indian sub-continent.

The Detroit Zoological Society is a world-renowned leader in animal welfare, and an important convergence between wildlife conservation and animal welfare is the reduction of human-wildlife conflict. Far too often, humans perceive wildlife as having negative impacts on their productive activities and security – particularly in the case of large predators – which leads to the regular practice of animals being killed. As the largest predator in Armenia, the brown bear (Ursus arctos) suffers heavy persecution from intrusions into farmlands and perceived threats to human life. A recent global survey of the human-bear conflict emphasizes the need for investigations into the effectiveness of various approaches to mitigate the conflicts, such as providing compensation for damage to fields and the use of electric fencing to prevent bear intrusions. This is especially true for Armenia, where there is no current plan to alleviate the human-bear conflict, despite its ubiquity. Fortunately, there is great potential in Armenia for compassionate conservation work that mitigates the human-bear conflict and decreases the intances of humans killing bears in retribution.

I recently convened with our partners with the National Academy of Sciences to document the distribution and intensity of this conflict by conducting interviews and installing trail cameras. In early August, I travelled to the Shikahogh State Reserve in southern Armenia and the Vayats Dzor region in central Armenia. Our team connected with reserve officials, village leaders and landowners, and documented a great deal of evidence of this conflict including damage to orchards, fields and beehives – most interviewees indicated an increase in conflict over the last several years. To verify the presence of bears, we set trail cameras in the Shikahogh Reserve and adjacent villages as well as in the villages of Vayats Dzor.

We also gathered data on other wildlife in the area. For example, at one of the sites in the Vayats Dzor region, we heard reports of Eurasian otters (Lutra lutra); the camera we set in this area will take pictures of both bears and otters. Otters are endangered in Armenia and one of the threats comes from hunters mistaking otters for introduced nutria (Myocastor coypus) and other wildlife. There is potential for us to implement an education program that would educate hunters about the protected status of otters in the hopes that it would prevent them from killing these animals. In addition, several of the cameras at Shikahogh were set in areas that are also promising for endangered Persian leopards (Panthera pardus taxicolor). Shikahogh borders protected areas in Iran where underpasses were recently established to act as wildlife corridors. Evidence of leopards using these underpasses would be very significant.

The trail cameras will be moved and reset this fall and additional cameras will be set in new villages. Next spring, we plan to establish a robust estimate of the number of bears in Vayats Dzor by placing cameras in all or most villages. We will also analyze the time stamps on the photos together with the characteristics of the bears photographed. In the coming years, we will document the bear conflict in the Syunik region between Shikahogh and Vayats Dzor as well as northern Armenia and explore ways to mitigate the conflict, such as offering compensation programs, installing electric fencing and facilitating safe bear ecotourism, so the bear presence can positively impact the economy. The camera data will also be used to find important areas to potentially implement protected status. The National Academy of Sciences in Armenia is striving to set up a network of protected areas that will stretch across Armenia, linking Iran in the south with Georgia in the north.

Paul Buzzard, Ph.D., is the field conservation officer for the Detroit Zoological Society.

Experience a Story of Survival

Nearly three decades ago, a tiny Tahitian land snail called the Partula nodosa was declared extinct in the wild – only 26 individual snails remained. In a final attempt to save the species from being completely wiped from the Earth, those 26 snails were sent to the Detroit Zoo as part of a cooperative breeding program.

Animal care staff worked carefully to provide the best possible living conditions for the snails while focusing on their successful reproduction, which eventually resulted in the rescue and recovery of the species. Thirty years later, there are now more than 6,000 individuals living in North American zoos, all descendants from the original group that came to the Detroit Zoo. In the last two years, 160 of these snails have been sent to Tahiti for reintroduction in the wild.

Visitors to the Detroit Zoo can become a part of this story at Shelle Isle, an exhibit in the Wildlife Interpretive Gallery that features the conservation story of these tiny mollusks. Guests are transported to the Tahitian rainforest, surrounded by tropical plants. A short video tells the snails’ story from a stable population in the first half of the 20th century to their sharp decline in the late 1970s, when an attempt to protect farmers’ crops from African land snails went awry and the Florida rosy wolf snails that were introduced to control the population preferred to eat the Partulid snails. The video also includes footage from the release of the Detroit-bred snails in Tahiti in 2015. Guests are invited to feel the shell of a giant replica of the Partula nodosa and more closely observe its structure and form. A second monitor has a live camera feed into the p. nodosa habitat in a behind-the-scenes area at the Detroit Zoo, giving guests a glimpse of the snails’ daily lives.

A favorite feature in this space is a large, “fallen” log where tiny, exact replica snails sit. Two magnifying glasses attached to the log allow visitors to get a close view of these tiny creatures. Many of them have a yellow number painted on their shell, which represents the way the snails are tagged by scientists before being released in Tahiti in order to monitor their movements and survival. The few that don’t have numbers painted on them are meant to demonstrate the successful reproduction in the wild that researchers have already observed, and the project’s continued success.

For us, an important part of this story is that it focuses not on a charismatic megavertebrate, but on a species that is not well-known, isn’t found on nursery walls or represented in the rows of stuffed animals on a toy store shelf. Conservation is not a beauty contest; all animals are important and the Detroit Zoological Society (DZS) works tirelessly to conserve species large and small – including the tiniest and slimiest of snails. By supporting the DZS, you are a critical part of this important work.

– Claire Lannoye Hall is a curator of education for the Detroit Zoological Society.

Detroit Zoo Honored with International Conservation Award

The Detroit Zoo was recently honored along with eight other zoos with the 2016 International Conservation Award from the Association of Zoos & Aquariums (AZA) for our work with the Gorilla Rehabilitation and Conservation Education (GRACE) Center. Located in the Democratic Republic of Congo, GRACE is dedicated to rescuing orphaned Grauer’s gorillas, which are among the most critically endangered primates in the world. As the conservation and preservation of wildlife is paramount to the mission of the Detroit Zoological Society (DZS), we couldn’t be more proud of this partnership or of this achievement.

Sadly, the Grauer’s gorilla is endangered due to widespread habitat destruction, poaching and threats associated with the ever-growing human population, caused in part by regional conflicts and government unrest. However, GRACE bravely fights against this, taking in the gorillas that have been separated from their birth families and/or confiscated from illegal trading. The rescued animals are provided nutrition and medical care as they explore the facility’s 370 acres – the largest gorilla enclosure in the world – situated within a 1,235-acre forested area of Central Africa. The hope – and the goal – is that these majestic animals will also learn the skills necessary for an eventual return to the wild.

 

Founded in 2009, GRACE is overseen by a dedicated board of directors, which includes Ron Kagan, DZS CEO and executive director, who has also served as board chair. In addition to Ron’s valuable leadership, the DZS’s involvement with GRACE has also included financial and staff support. In 2015, Ron helped secure funds for a new night house enclosure for the gorillas. Also that year, DZS Director of Animal Health Dr. Ann Duncan traveled to the Congo to perform health examinations on 12 gorillas, which had never been done before.

This amazing conservation, welfare and humane education initiative is a wonderful collaboration of important organizations working together with a very special Congolese community to ensure that this population of extremely endangered gorillas survives.

The AZA’s International Conservation Award annually recognizes accredited AZA institutions and conservation partners that make efforts to restore habitats, preserve species and support biodiversity.  Our zoo partners who join us in receiving this award include the Los Angeles Zoo, Utah’s Hogle Zoo, Jacksonville Zoo and Gardens, Nashville Zoo, Houston Zoo, Dallas Zoo, Sedgwick County Zoo and Disney’s Animal Kingdom.

We are looking forward to continuing our partnership with GRACE and dedicating our efforts to ensure the safety of the beloved Grauer’s gorilla for generations to come. This partnership is arguably the most exciting, unique and promising conservation, welfare and humane education initiative the Detroit Zoological Society has ever been involved with.

Veterinary Care: Ultrasound Exams for Frogs

Spring is in the air, and as I hike and bike the trails in southeast Michigan I find myself excited to be immersed in the lovely chorus of spring peepers and tree frogs as they prepare for this year’s breeding season. This also means it won’t be long until it is amphibian breeding season at the Detroit Zoo! Each year, the veterinary team works closely with our amphibian staff to provide support for our amphibian breeding programs. Our curators and keepers set up special breeding areas and adjust the temperature, light cycles, humidity and water access to simulate conditions in the wild and encourage natural breeding. They even set up simulated rainfall and play tape-recorded sounds of breeding calls collected from the wild.

Even with all of this, some of our endangered amphibians need a little more help to breed successfully.   At the Detroit Zoo, we have over a decade of experience administering special hormones to Wyoming toads and Puerto Rican crested toads to help with breeding. We have been very successful with these programs; two years ago the amphibian staff sent 3,914 Wyoming toad tadpoles to Wyoming and last year they sent 22,571 Puerto Rican crested toad tadpoles to Puerto Rico for release into their native habitat. This is important work and we are proud to be able to help.

As zoo husbandry staff and amphibian reproductive experts have gained expertise, it has become clear that not all amphibians respond the same way to changes in their environment and established hormone protocols. Two years ago, we purchased a high frequency ultrasound probe, and we have found that we can monitor the appearance of the ovaries and follicles as they develop and mature within female frogs and toads. This provides a very powerful tool for understanding the impact of the husbandry and hormone treatments that we apply, and will allow us to establish assisted reproduction methods for other endangered species.

This season we have some exciting things planned, and have started the early work to check the females we are hoping to breed. Last week, we performed ultrasound exams on our three female giant waxy tree frogs, and were able to see that they are all developing large, follicle-filled ovaries. Based on the appearance of the follicles, we think that they will be ready to breed in the next few weeks to a month.

This week, we will be conducting ultrasound exams on our endangered Mississippi gopher frog females. Once we see their degree of follicle development, we’ll be able to plan a hormone and husbandry strategy for this year’s breeding season. Hopefully we will have exciting news to share in the coming months!

– Dr. Ann Duncan is the Director of Animal Health for the Detroit Zoological Society and oversees the Ruth Roby Glancy Animal Health Complex.

Amphibian Conservation: Breeding Puerto Rican Crested Toads

April is an important time for the Detroit Zoological Society’s amphibian conservation programs. Three of the four animals we work with at the National Amphibian Conservation Center (NACC) that are a part of Species Survival Plans (SSP) are preparing to take part in precisely planned and scheduled breeding events. The outcome is the release of captive-born offspring into the wild to aid in the increase of their populations.

First up for the season is the Puerto Rican crested toad, Peltophryne lemur. The PRC toad, as we like to call them, has been part of a well-managed SSP since 1984. Habitat loss and competition from the invasive cane or marine toad (Rhinella marina) are believed to have been primary causes for the toad’s decline. Listed as critically endangered by the International Union of the Conservation of Nature (IUCN), collaborative efforts by the Associations of Zoos and Aquariums, U.S. Fish and Wildlife Service and the Puerto Rico Department of Natural and Environmental Resources have aided the recovery of this toad in the wild. More than 300,000 captive-bred tadpoles produced by 20 zoos have been released to the wild since 1982. Since the year 2000, the Detroit Zoological Society has produced more than 45,000 tadpoles for this program. In 2015, three clutches of eggs laid produced 22,571 tadpoles for release – the largest amount the Detroit Zoo had ever sent. Ongoing research and the creation and protection of pond habitats have also assisted in the recovery of this toad in its natural habitat.

You may be wondering what it takes to produce thousands of tadpoles from toads half the size of the palm of your hand. The breeding season starts with the assignment of four breeding pairs from the SSP. Each toad in captivity is identified and tracked using a studbook. Specialized software chooses pairs of toads that will produce the most genetically diverse offspring. By mid-March, we know who these eight toads are and we can begin preparing them for breeding.

Each toad must be easily identifiable – if you think all toads look alike you’ll be surprised to know that wart patterns and throat markings are very unique, although reading glasses are sometimes needed to make the proper ID. Toads are conditioned by slightly cooling and drying their environments out for a month-long period. A thermostat-controlled refrigeration unit keeps the toads cooled precisely at 66 degrees Fahrenheit. While the toads are “sleeping”, their primary zookeeper works diligently on preparing the breeding tanks where the pairs will breed and the eggs will develop. At this same time, veterinarians prepare a schedule of specialized breeding hormones that will further assist in ensuring that eggs are laid and fertilization happens at the right moment.

Upon their exit from cooling, they return to normal husbandry to warm up and eat for a few days. Breeding calls of male toads are played to encourage breeding behaviors. Males are first to go into the breeding tanks, followed hours later by the females. If all the preparation works, pairs of toads will be in amplexus – which happens when a male is positioned on top of a female and he squeezes her to encourage egg-laying – before we leave for the evening, followed by a morning of tanks full of eggs.

It takes two to three days for eggs to hatch and another couple of days for tadpoles to begin swimming around and actively eating. Tadpoles can be some of the hungriest creatures you will ever encounter. Keepers spend the next 10 days keeping them fully fed by offering them algae pellets, powdered diets and romaine lettuce sometimes three times a day. At the same time, all those foraging tadpoles create a lot of waste, so keepers spend the rest of their time keeping their water clean with frequent water changes.

During all of this, we keep a very important date in the backs of our minds – the last big event in our PRC toad breeding season. Any facility that breeds the PRC toad needs to ship them to Puerto Rico for release on the same date. The release of the tadpoles is timed with the season in which the tads would grow and develop the best in the wild. Tadpoles also need to be shipped at a certain age, before they get too big and begin to develop appendages.

Amphibian staff can spend well over 24 hours collectively counting and packing the tadpoles into Styrofoam-protected shipping boxes. Heavy-duty fish shipping bags are used, doubled up and filled with oxygen to keep tadpoles healthy and safe on their trip to Puerto Rico. Approximately 24 hours later, they will reach their new home in a pond located in a well-protected forest in Puerto Rico. As they develop and grow, they will add to the wild population and one day, hopefully, participate in creating many more thousands of tadpoles!

Rebecca Johnson is the associate curator of amphibians for the Detroit Zoological Society.