frog

Detroit Zoological Society Helps Students Explore Alternative Dissection

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Millions of frogs are dissected every year in science classrooms across the country and unfortunately, many of these animals are taken from the wild. With more than half of all amphibian species at risk of extinction, it is critical to leave amphibians in their native habitats.

This summer, the Detroit Zoological Society’s Berman Academy for Humane Education purchased state-of-the-art virtual-reality frog dissection software. Combined with 3-D models, students can participate in an engaging, hands-on humane dissection alternative. In its current form, this alternative dissection approach is instilling a better appreciation for amphibians in classrooms, camps and other education programs.

During the DZS’s Summer Safari Camp at the Detroit Zoo this summer, students entering eighth grade focused on veterinary medicine as a potential career. Through this lens, campers used iPads to explore, rotate and connect how a frog’s physiology works beneath the surface. The augmented reality part of the app allows students to zoom in and manipulate the view of the virtual frog on their tables. Hands-on models of the same species of frog allows them to physically take apart and reassemble parts of the frogs’ anatomy. This experience, combined with a guided tour of the National Amphibian Conservation Center, gave campers the opportunity to see frogs in a different light.

Middle school teachers can schedule their class to visit the Zoo to participate in a Learning Lab focused on virtual dissection. In this program, students use the virtual reality software on a classroom set of iPads to learn about frogs and dissect them, without the cost and environmental impact of taking amphibians from the wild. The software also allows students to go through the process multiple times, to better understand frog anatomy while ensuring wild populations of these critically important species are not compromised.

For more information or to schedule a classroom for the Virtual Dissection Learning Lab, visit https://detroitzoo.org/education/school-groups/ or email us at education@dzs.org.

– Carla Van Kampen is a curator of education for the Detroit Zoological Society.

Amphibian Conservation: Saving the Panamanian Golden Frog

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The Panamanian golden frog (Atelopus zeteki) is a unique and beautiful amphibian from the highlands of Panama. This yellow or orange and black “frog” is actually a type of toad that walks more than it hops. It resides in areas near fast-moving streams and rivers in the mountainous forests within the country. The International Union for Conservation of Nature (IUCN) lists the Panamanian golden frog as Critically Endangered, which is one step before becoming Extinct.

In the wild they are believed to be in such low numbers that they may no longer be able to sustain as a wild population; in fact, no one has seen a Panamanian golden frog in the wild for quite some time. Massive population decreases are believed to be caused by chytrid fungus, habitat destruction, the exotic animal trade and sedimentation of egg-laying sites in rivers and streams. Now, they exist mostly in captive zoo breeding populations.

One of these breeding populations has been housed in a bio-secure room at the Detroit Zoo’s National Amphibian Conservation Center for 16 years, and has contributed several years of offspring to the Panamanian Golden Frog Species Survival Plan (SSP). SSPs are cooperative management programs through the Association of Zoos & Aquariums (AZA) that aim to reproduce, genetically manage and possibly reintroduce endangered animals into the wild with the assistance of other wildlife management organizations. In addition to its active role in the SSP, the Detroit Zoological Society (DZS) employs several other strategies to conserve the Panamanian golden frog in the wild. At this time, there is nowhere identified in the wilds of Panama to safely release captive-bred tadpole or juvenile golden frogs to the wild.

Breeding the Panamanian golden frog in captivity involves understanding the complex conditions found in their wild habitat. They have an interesting life cycle from courtship to final metamorphosis. In the wild, males of this species will perch on rock outcroppings or on top of large leaves that overhang or are near a flowing stream or river. The males then begin to call, thrusting out the vocal sacs on their throats as they produce a low trill vocalization meant to alert females to their presence as well as warn other males to stay away. Since these animals breed and live in close proximity to the loud sound of rushing water, their low-toned vocalizations can be very difficult to hear. For this reason, golden frogs have evolved a type of sign language they can use to communicate to mates as well as rivals. These amphibians have the ability to execute a “wave” using their front legs to take the place of their hard-to-hear vocalization when conditions around the stream are noisy. This type of communication is known as semaphore behavior.

Once a pair of golden frogs has successfully mated in the wild, the female will deposit up to several thousand small round white eggs underneath a rock in a steam or river and away from direct sunlight. This is done because the white eggs lack pigment entirely and would be adversely harmed by the ultra violet (UV) radiation from the sun. This same issue has to be addressed at the Detroit Zoo. The animals are bred inside aquariums in a specially modified room just for this species. After the breeding pairs are chosen for the year, the animals are placed together in an aquarium. Prior to the onset of the “wet season,” misting cycles within the frogs’ habitat are coordinated to simulate the “dry season,” giving the frogs a sense of seasonality, which helps stimulate them to breed. If eggs are laid in the aquarium, amphibian staff must protect the eggs from the naturalistic UV lighting over the breeding tanks by wrapping black trash bags around the aquarium. This simulates total darkness, which allows the light-sensitive eggs to develop unharmed. Once eggs develop pigment, the trash bags can be removed.

Eventually, the eggs develop and a small black and yellow tadpole emerges from the egg casing. These tadpoles are very well adapted to living in fast, flowing stream environments with strong mouthparts which assist them in clinging to the rocks in turbulent water as they scrape away at algae and the microorganisms they depend on for food. At the Detroit Zoo, we reproduce the golden frog food source by smearing a wet algae mix on small plastic food plates and allowing the mixture to dry. Once the algae is dry, the plates are placed in the water and the tadpoles move over and around the plate, scraping off the food with their specialized mouthpart. After several weeks, the tadpoles metamorphose into fully formed little toadlets, which are turquoise green and black in color, a color phase that camouflages them in while living in a forest habitat. They eventually turn mostly yellow or orange and black upon reaching adulthood.

Along with the extensive breeding program, conserving the Panamanian golden frog involves reaching out to the communities where these animals live and educating the public. In 2015, I assisted the staff at a small conservation center in El Valle, Panama, called the El Valle Amphibian Conservation Center (EVACC). This center is dedicated to breeding, exhibiting and educating the public on Panama’s native amphibians. While in Panama, I assisted EVACC with their amphibian exhibits and breeding programs. The DZS is also becoming involved in developing educational materials to better educate an already sympathetic public about conserving their environment and this important amphibian. Recently, DZS Curator of Education Claire Lannoye-Hall has been appointed as the SSP Education Advisor for the Panamanian Golden Frog SSP. Within this role, the Detroit Zoo will be instrumental in developing educational programs and cultural awareness within Panama.

The Panamanian golden frog holds a special place in the Panamanian culture. Signifying good luck, the golden frog can be seen on lottery tickets and in gift shops all around the country. The history of this little amphibian within Panama can be illustrated by the presence of “rana dorada” or golden frog, in some of the petroglyphs within the country dating back to pre-European contact. Perhaps those ancient artists were hoping for a little luck as they etched images of this mystical amphibian into the rocks of the cloud forest. Hopefully, with a little of that same luck and continued dedication from the Detroit Zoological Society and its conservation partners, the Panamanian golden frog will not disappear from history for good.

– Mark Vassallo is an amphibian department zookeeper for the Detroit Zoological Society, and works in the National Amphibian Conservation Center at the Detroit Zoo.

Amphibian Conservation: Crawfish Frogs in Crisis

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What is the best way to repurpose a basement in one of the buildings at the Detroit Zoo? Turn it into an amphibian’s paradise!

Amphibians across the globe are in crisis, with populations declining rapidly due to climate change, habitat destruction and a disease called the chytrid fungus. In an effort to reverse this trend for the crawfish frog (Lithobates areolatus), which is listed as Endangered in the state of Indiana, the Detroit Zoological Society (DZS) partnered with the U.S. Fish and Wildlife Service, the Department of Natural Resources and staff at Indiana University. In 2013 these entities began a repatriation project, which is an effort to return a species to its natural habitat. This involved the collection of egg masses from grasslands in Indiana, which were then transported to the Detroit Zoo, where staff raised them until they were almost froglets before releasing them back into the wild.

The crawfish frog can lay egg masses with as many as 5,000 eggs. That might make one wonder how these animals could be endangered, right? Well, even if all of those eggs hatched into tadpoles, less than one percent of those tadpoles would ever make it out of the water. Tadpoles are an easy prey for a wide variety of animals including birds, fish, mammals, frogs and even larger tadpoles. And even fewer tadpoles would make it far enough into adulthood to breed. This shows how vulnerable the tadpole stage is in a frog’s life, which is why we focused our efforts on this stage.

We knew what we needed to do, but where is there enough room for thousands of tadpoles at the Detroit Zoo? How about right under the noses of Jasiri and Tamba, two Southern white rhinos! Not directly under them, since 12,000 pounds of rhino would be harmful to a tadpole, but rather in the basement of their indoor habitat. It took a lot of hard work from staff, but the space was eventually turned into a fantastic temporary home for crawfish frog tadpoles. Some of their luxury items include manufactured ponds with an automatic rain system, spotlights and temperature control systems – and of course, plenty of food.

In April, the crawfish frog egg mass is transported from Indiana to the Detroit Zoo in a cooler. We take this egg mass right down to the basement where it is placed in water. In a couple of weeks, tadpoles start to emerge, which are then counted and moved into long pond-like pools. We raise these newly hatched tadpoles for about three months, with the amphibian department staff feeding and cleaning them daily. It takes hours to care for the tadpoles each day, but it is all worth it in the end when they are driven back to Indiana and released. The total number of tadpoles varies from year to year, but since this project started in 2013, the DZS has released a total of 10,411 tadpoles back into the wild.

While wild tadpoles have less than a one percent chance of survivability, we were able raise that to an astounding 99 percent in 2014 and 2015 for these “basement” tadpoles. That’s because they don’t need to worry about predators, disease, lack of food or pollution. This lets them get a good head start on life – but we don’t make it too easy for them. Otherwise, they wouldn’t know what to do once they got back to the wild. So before they fully metamorphose – or turn into frogs – they are taken back to Indiana and released into the ponds. Since some frogs lead a “double life” – aquatic and terrestrial – they are able to finish their aquatic life stage in enclosed repatariums, or screened-in containers, that allow protection before they are released as full frogs in the environment in which they will live. This method works well and provides exposure to the environment they will be living in before they become too accustomed to the luxury of the rhino basement.

The DZS crawfish frog conservation project requires long hours, but it is also the best time of the year as a member of the amphibian department staff. Seeing how the DZS can make a positive impact on this species and the ecosystem is very rewarding.

– Michael Andrus is an amphibian department zookeeper for the Detroit Zoological Society and works in the National Amphibian Conservation Center at the Detroit Zoo.

Notes From the Field: Amphibian Diversity in Peru

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Hola mis amigas y amigos!

My Peruvian friends have been telling me that the last few months have been very dry, so I had no idea what to expect upon my arrival. I was very surprised to see that the Amazon River was at least 30 or more feet lower than when I was here in March, which could potentially have a huge impact on what amphibians we see. Areas where there would normally be ponds could be completely dry. As you can imagine, I couldn’t wait to get out into the rainforest and see what may be waiting for us.

Unfortunately, my suspicions were accurate and amphibians were much harder to find than usual. Since we monitor some of the same areas year after year, I had a pretty good hunch on where and what I might find in certain areas. When we have time, we always check other areas but our priority is to first survey our research sites. Among many other pieces of data we have been collecting, we are looking at diversity and abundance of species – basically, what types of frogs and toads and how many. This year seems to be the most obvious change, likely, due to the dryness. The humidity levels even felt different – normally my skin stays moist but this time I was using lotion.So far, the most interesting or peculiar sighting was a toad that had climbed a tree. The toad, common to South America, was at least four feet off the ground with no visible easy climbing point. I can hardly wait to see what else we may find!

Buenos noches!

– Marcy Sieggreen is the curator of amphibians for the Detroit Zoological Society and is doing fieldwork in Peru, studying amphibians in the lower elevations of the Amazon River to see how they are faring with increased human populations and impacts in their habitats.

Editor’s note: Marcy Sieggreen was the curator of amphibians for the Detroit Zoological Society from 2008 until her passing in 2016. The Detroit Zoological Society established the Sieggreen Amphibian Conservation Fund in Marcy’s memory to continue to advance the work she so passionately championed.

Notes from the Field: Two Weeks in the Panamanian Jungle

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Recently, I found myself trekking through the jungle, holding a machete, in search of the perfect piece of wood. This wasn’t a typical day of work for me with the Detroit Zoological Society (DZS) – I’m usually found in the National Amphibian Conservation Center (NACC) at the Detroit Zoo, changing filters, cleaning misting lines and feeding tadpoles. But on this particular day, I was in El Valle, Panama, a small town situated in the valley of an extinct volcano; the historic home to the Panamanian golden frog (Atelopus zeteki), a species that is critically endangered in the wild.

The DZS has maintained a breeding population of Panamanian golden frogs at the NACC since the year 2000 as part of the Association of Zoos and Aquariums’ Species Survival Plan, a cooperative management program that ensures genetically healthy, diverse and self-sustaining populations of threatened and endangered species. Since I personally care for and breed this delicate species at the Detroit Zoo, it was truly awe-inspiring for me to travel to Panama; to see and experience the tropical cloud forest habitat that was home to the golden frog until the late 1950s, when the last sightings were reported in the area.

Like many amphibian population declines worldwide, the threat to the Panamanian golden frog is a multi-pronged, human-induced sucker punch of climate change, de-forestation and over-collection for the pet trade. Also, a very serious parasitic fungus known as Batrachochytrium dendrobatidis or “chytrid Bd” [ki-trid] became present in the area. This fungus thrives in the environment of a cloud forest and caused a dramatic decline in amphibians through the region.

Despite the thrill of viewing some amazing wildlife on our walk through the Panamanian jungle, I wasn’t there to enjoy the scenery. My purpose in traveling to El Valle was to assist the limited staff at the El Valle Amphibian Conservation Center (EVACC), a small conservation center dedicated to breeding and researching the country’s most endangered amphibians, as well as educating the community in Panama about the amphibians in the area.

For two weeks, I trained the staff at EVACC on habitat design and maintenance. I shared techniques for designing water features, drilling enclosures for bulkhead placement and “propping” habitats – gathering supplies like logs, plants and rocks to create a naturalistic environment. One day was dedicated to removing and replacing an old “roof ” of a habitat planned for golden frogs, which was the size of a living room. Other days involved finding things like sticks, logs and foliage to prop the habitats, and since all of the animals were from the surrounding area, most of what we were collecting could be found and disinfected within the grounds of the conservation center.

The EVACC’s newly designed habitats would be playing an important role in the “Golden Frog Day” in El Valle, a celebration of the magical amphibian that once lived and thrived among the misty forests of the mountains. Without public support in its country of origin, there could be no future for this animal. With newly renovated habitats and the beauty of this vibrantly colored amphibian, visitors to the center can begin to understand the value of this species and the power it holds as members of the community work to conserve it.

A true reward for all of this hard work and training came several days after leaving Panama, when I received an email from EVACC staff informing me that they had drilled their first tank and were using techniques that I taught them to install a new waterfall feature. While I had ditched my machete and my head lamp, no longer needing to trek into the jungle for my work with the Panamanian golden frogs at the Detroit Zoo, I know that the work we are doing some 4,000 miles away from their home is just as critical to the survival of this incredible species.

– Mark Vassallo is an amphibian department zookeeper for the Detroit Zoological Society.