frogs

A Song in the Darkness: Audio Loggers and Panama’s Imperiled Amphibians

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Authored by Mark Vassallo, Detroit Zoological Society (DZS) Amphibian Department Supervisor.

The cloud forest of central Panama is a unique and mysterious place, full of rare creatures and plants that call these moisture-laden peaks home. At night, the jungle writhes with life as the nocturnal world takes over the mountainsides. In this veil of darkness and nestled in the elevations of these dense jungles, some of the earth’s rarest amphibian species reside. Many of these species are yet to be described by science, and others are considered to be extinct.  As I gazed up at the gathering rain clouds on the volcanic peaks of El Valle, I could not help but wonder which of these potentially extinct amphibians could still be out there.

I have been traveling to El Valle, Panama for the last seven years to work with the El Valle Amphibian Conservation Center (EVACC). This organization is run by Edgardo Griffith and Heidi Ross, a husband-and-wife biologist team, who have dedicated their lives to the conservation of Panama’s most endangered amphibians. Usually during these trips, I am undertaking projects involving the installation of life support and infrastructure or helping troubleshoot specific husbandry issues that arise in one of the modified shipping containers in which EVACC houses seven species of Panama’s rare and endangered amphibians, including the iconic Panamanian golden frog (Atelopus Zeteki). 

A Warzewitsch’s frog was identified in the area.

While those types of jobs are on the docket for this trip, we also have an important task to complete that will bring us into the upper reaches of the cloud forest in the hopes to hear a sound that could mean some hope for the imperiled amphibians of Panama. The sounds we are hoping to hear are the calls of thought-to-be-extinct amphibians, including Raab’s tree frogs (Ecnomiohyla rabborum), large and highly unique arboreal frogs who lays their eggs in tree cavities and can glide through the air to evade predators. In the last year, EVACC has begun the process of deploying audio loggers in some of the area’s hard-to-reach elevations to listen for the calls of amphibians like the Rabb’s tree frog that are widely thought to be potentially extinct. 

The audio loggers are sturdy boxes that contain a microphone, batteries and SD cards accompanied by a digital screen. The idea is that these listening devices, which are programmed to turn on during the dusk and nighttime hours, will pick up the call of one of these rare frogs. If a call from one of these frogs is detected on the logger recording, this would give the biologists at EVACC a very good lead on the areas where intensive surveys could take place to potentially locate this species.

Armed with some GPS coordinates, batteries, fresh SD cards and rough information about the audio logger’s location from a member of the last group who placed it, we headed up the mountain to start our journey. As we began to climb, the heat and humidity was intense — our clothes were soaked in less than an hour.  Large biting ants were swarming our boots as the incline steepened, and we came to a crossroads in the trail. We had reached the GPS coordinates but realized that these coordinates could not be correct. At this point, we decided to attempt to leave the trail and start climbing up what seemed like a cut in the dense jungle, which may have been caused by mudslides and heavy rains, certainly nothing even resembling an actual trail. The going was difficult as the clouds began to gather. Buckets of heavy rain soon began dumping on us, causing the mud to loosen and give, making the more vertical sections especially precarious. In addition to watching your footing in the jungles of Panama, it is also important to watch where you put your hands. Eyelash vipers and stinging insects of all kinds tend to rest on branches and sticks at about eye level. All of these thoughts were keeping our senses sharp as we broke through clearing after clearing, each time hoping that this was the top of the mountain and the audio logger would appear like a shining beacon amongst the dense jungle. Yet, each time the clearings revealed even more vertical walls of vines and thick jungle vegetation to climb. Our resolve was fading, but we pressed on. At one point, my balance gave way, and I fell face first into the side of the muddy slope. As I raised my head, I noticed I was face to face with a tiny gem of a frog. It was a blue-bellied poison frog (Adinobates minutus). This toxic little frog was just staring back at me, probably wondering why a silly, hairless ape had bothered to climb this far up a mountain during a thunderstorm. 

A rainforest rocket frog was identified in the area.

The rain was finally letting up, and this gave us a little boost as we could see some sunshine emanating from what looked like a break in the jungle ahead. As we approached, sharp painful sensations started overwhelming my hands and wrists. We were wading through a large column of sharp bladed grass, which when brushed against, caused a paper cut like lacerations on the skin. Once we emerged from the brush and into the clearing, we realized we had reached the top. The jungle was so dense there was no real spot to even look out to enjoy the view. We immediately got to work searching for the audio logger.  I looked left then right and passed through some thick brush. Then I saw it — a strip of white that stood out in the landscape of green. It was one of the zip ties used to attach the logger to the tree. We had found it! After several minutes of exulted celebrations and numerous high fives, we swapped out the SD cards and batteries, the unit was reprogrammed, and we locked up the protective case. The trip down was more like a ride down a luge course made of mud. This did make the process faster but certainly not any safer. 

Once we finally arrived back at the EVACC grounds, we were exhausted and coated in mud and insect bites but satisfied and content that we had achieved a seemingly insurmountable challenge. After a shower and a cold beverage, I walked out into the moonlight on the grounds of EVACC. Once again, the clouds were beginning to gather around the El Valle mountains, and my eyes settled on the tips of those green jungle peaks, wondering if the logger we had reset for another four months would record a sound of hope.

Learn more about the EVACC foundation and make a donation online to help them ensure the survival of Panamanian amphibian species for generations to come.

Mark Vassallo is pictured with an audio logger.

Amphibian Breeding Season

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Spring is the time of year when most amphibians in the wild are emerging from hibernation, breeding, and eventually laying eggs. This pattern also holds true for the animals at the Detroit Zoo’s National Amphibian Conservation Center (NACC). Every year in the early months of spring, the top-notch staff at the NACC facilitate hibernation, breeding and rearing for endangered amphibians from all over the world with the intention of releasing them into their respective habitats in the wild. A few of these species include Wyoming toads (Bufo baxteri), striped newts (Notophalmus perstriatus) and Puerto Rican crested toads (Peltophryne lemur). Amphibians are highly sensitive creatures who rely on the environmental conditions of their native habitats to cue their natural cycles of breeding and to maintain their overall health.  The NACC staff are experts at recreating these environmental cues.

Facilitating breeding in Wyoming toads, for example, is a complex process involving temperature changes and natural material for burrowing. The amphibian staff use a refrigerator to replicate the natural winter cool down experienced by these critically endangered creatures, and to ease them into a state of lowered activity and metabolism. The amphibians are also provided with a special mix of substrate to burrow into during this period – very similar to how Wyoming toads in the wild burrow below the frost line during the cold months.  When they warm up after this simulated winter, the toads at the NACC are ready to breed and are paired up with mates according to the recommendations of the Association of Zoos & Aquariums’ (AZA) Species Survival Plan (SSP) for Wyoming toads. An SSP is a cooperative breeding program that is overseen by AZA-accredited institutions that breed and house animal species who are endangered or threatened.

Another example of the specialized care required to breed the unique animals at the NACC is found in the reproduction patterns of striped newts. Endemic to the long leaf pine forests of Georgia and Florida, these amphibians are known to congregate and breed in temporary pools during specific times of the year when the water levels are highest.  In order to mimic these events for the striped newts at the NACC, their habitats’ water levels are lowered for a period of time – before being raised dramatically. The natural breeding cues of the striped newts are also replicated in other ways, such as changing their “photo period,” or daylight/nighttime hours, in order to simulate different seasons.  Inside the animals’ habitats, the zookeepers also place specific aquatic vegetation that the newts have been known to prefer as sites for laying eggs.

            Puerto Rican crested toads are among the many amphibians who are known to begin breeding activities during periods of heavy and sustained rainfall. Existing only in several small isolated populations within Puerto Rico, these toads emerge from hiding during seasonal rains to find a mate and reproduce.  Making use of this knowledge, the intuitive keepers at the NACC have produced a “love song mixtape” which includes the calls of male crested toads as well as the sound of heavy rainfall. While this track may not win any Grammy Awards, it serves to stimulate the crested toads into amplexus, which is an embrace used by male toads to hold onto the female and fertilize her eggs.

After countless hours of logging temperatures, researching literature and testing water quality, the real reward comes for the staff at the NACC when these fragile and endangered animals are released into the wild having received a head start towards a brighter future. This year, in the month of June, the amphibian department at the Detroit Zoo released 3,393 Puerto Rican Crested Toads, 634 Wyoming Toads and 41 Striped Newts into native habitats ranging from the dry forests of the Caribbean Islands to the plains of Wyoming. The amphibian staff take great pride in having contributed to the conservation of some of the most important animals on the planet as well as in furthering the mission of Detroit Zoological Society.

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

Frog-Themed Activities in Honor of World Frog Day!

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Spring is finally here — and so is World Frog Day! The weather is gradually warming up and plants are bursting through the soil, preparing to dazzle us with their blooms. Spring also brings the beautiful sounds of frogs and toads calling to each other. In honor of World Frog Day, we are sharing frog-themed activities that can be done at home with minimal supplies.

PT Borneo eared frog

Frogs live on six of the Earth’s seven continents, all of them except Antarctica. They are all different colors and sizes. The largest species of frog, the goliath frog, measures 8” to 12” in length. That is about the size of a piece of copy paper!  The smallest known frog, one of the microhylid frogs, measures less than half an inch, about the width of a regular size paperclip. If you have children at home, pull out a paper clip and a piece of copy paper. Have them compare the items to objects around the house to see what is larger than the world’s largest frog and what is smaller than the world’s smallest frog. Comparing sizes of different things helps people build number sense, or an intuitive understanding of numbers, an important skill for all of us to master, especially young children.

Green Mantella - Adam Dewey

Michigan is home to 13 species of frogs and toads. It is usually easier to hear them calling or singing to each other, than it is to actually see them. That is because they are well camouflaged, meaning they blend in with their surroundings. It is important to know which species of frogs and toads live in certain areas. They are considered bioindicators, which means they are species of animals who are greatly impacted by the health of the environment. If the water, wetlands and other places they live are polluted or contaminated, they cannot survive. If their habitat is clean and healthy, many species or individuals will be living there, all calling out to each other in a beautiful chorus.

FrogWatch - Bullfrog

The Detroit Zoological Society (DZS) leads a FrogWatch Chapter (aza.org/frogwatch and detroitzoo.org/animals/frogwatch/) to train people, like you, to recognize and record frog calls around Michigan. The data that people submit helps DZS staff and researchers to analyze and better understand frog populations throughout our area and across the country.

IMG_0474

This spring, consider spending time outside in the evening to listen for frogs and toads. You can practice being a frog and toad researcher, or a citizen scientist, by learning the calls and recording information like date, temperature, weather conditions, the time you start and stop listening, and the species you hear. The Michigan Department of Natural Resources has short recordings of each species on their website to help you learn them. Practicing recording data is an important skill, especially for kids. Send your data to Rebecca Johnson (rjohnson@dzs.org) or Mike Reed (mreed@dzs.org). Next year, you can join us for training to become a certified FrogWatch participant. The earliest calling frogs will be starting soon, the wood frogs and spring peepers, so pick a night where the temperature is above 40 degrees Fahrenheit and head outside to listen!

 

Notes from the Field: Protecting Amphibian Biodiversity in Peru

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You heard recently from one of our education experts about how the Detroit Zoological Society is working with Peruvian schools to conserve the rainforest through outreach and education. Conservation of the biodiversity in the Peruvian rainforest has been a priority of the Detroit Zoological Society for over a decade, and we have many programs in the rainforest that help to achieve this goal. One of our programs focuses specifically on amphibians, and that is where I have the great fortune to visit this incredible location.

Boana calcarata

There are over 600 species of frogs in Peru, with more species discovered every day. With this high number of species, Peru is called a “biodiversity hotspot.” These “hotspots” are very important to monitor for changes, because while there are many species they are all very dependent on one another. Small changes can cause drastic effects. Amphibians are some of the most sensitive animals, because their skin absorbs everything in the environment. If amphibians begins to get sick or have difficulty surviving, that is an excellent clue that something is wrong in the environment. All over the world, amphibians are currently having difficulty with changes we are seeing in the environment- because we are seeing global changes, it is extra important to study the animals in areas like the Amazon, where amphibians are in higher concentration, to try and understand patterns in these changes.

Boana calcarata call image

The convict tree frog (Boana calcarata) is a frog found in the Napo River region. This sound recording and image were made by the National Amphibian Conservation Center during a survey.

In order to keep an eye on the amphibians in the Peruvian Amazon, staff from the Detroit Zoo’s National Amphibian Conservation Center conducts surveys for frogs twice a year. This means we physically go out and look for frogs. Because we know we cannot possibly see all the frogs, also record the songs of frogs at night. Hearing the songs can help us guess numbers of animals singing and help us to hear the songs of species that are difficult to find on visual surveying. In addition to surveys, we monitor weather data in the Napo River valley. We have our own weather station that collects year-round information about the valley region. We also use small data loggers to collect immediate, specific “microclimate” changes where we visualize species breeding (for example: on a specific plant or under leaf litter). The weather data helps us understand both immediate changes in behavior of frogs, as well as changes in populations over time.

Weather stationDr. Ruth Marcec-Greaves downloads six months’ data from the weather station.

While data collection and surveying are important, fostering appreciation of animals in the local community is the primary goal of the visits to Peru. Our hope is that educating the community and creating excitement in future generations will help to preserve these animals for the future. The “Club de Protectores de Anfibios,” or Amphibian Protectors Club, is a club comprised of high school students that are local to the Napo River valley region. The club was founded in order to help impart enthusiasm for amphibians and the environment.

In Peru, there are many misconceptions surrounding frogs. There is a general belief that frogs are bad luck and should be kept away from homes. When the Detroit Zoo staff visited the Amphibian Protectors Club in June of 2019, the club members taught us how the Amphibian Protectors Club is changing the community. The club members performed a play in which they explained another local belief is that a woman will become pregnant if she spends time around frogs. Told from the perspective of high school students, this was a chilling superstition. Through the play, the students explained that by participating in the club they have learned not only that this is a myth, but also frogs are important for human health and humans need to protect frogs. The club members have taught their friends and families frogs are important and have begun to see more frogs in their villages since this change in attitude.

Night HikeAn Amphibian Protector’s Club member observes a frog up close on a night hike.

The students from the club went on an overnight excursion with the National Amphibian Conservation Center staff, where we visited one of our regular field research sites. We took a late night hike in order to see frogs calling and breeding at this special location. At this site, we saw species of frogs the students do not commonly see in their villages. After a good night rest, the club rose early in the morning to hike to the nearby canopy walkway- a breathtaking experience where the club members were able to look down on the rainforest from the treetops. While these students live in the rainforest, many of them have not seen their tropical home from this perspective. They were inspired by this view, observing the unique habitat of rare and diverse species. One club member called it “the view of the animals,” and asked very advanced questions about some of the plants and insects he observed.

Canopy

This was an incredibly rewarding trip. The students showed us that their appreciation for the amphibians is making a difference. While I will not see them in person for a few months, the students will continue to speak with me over a WhatsApp chat (they named our group “Whatsappos,” because “sapo” means toad in Spanish). While I am away, the club meets monthly to survey in their home towns and the students will send me photos and descriptions of frogs the see. Over the app, we talk about the species and have a question and answer session. Their excitement is inspiring and infectious, and I am confident their enthusiasm will be what helps save species.

– Dr. Ruth Marcec-Greaves is the director of the Detroit Zoo’s National Amphibian Conservation Center.

 

 

Detroit Zoological Society Leads Task Force to Evaluate Risks Facing Honduran Amphibians

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The International Union for the Conservation of Nature (IUCN) recently asked the Detroit Zoological Society to host an Amphibian Red List workshop in Honduras. The IUCN Red List is the world’s most comprehensive information source for understanding extinction risk for animals. To develop this list, a rigorous assessment process is conducted using all known data on each species. Based on what threats the animals are facing, e.g., habitat decline, population decline and habitat fragmentation, the animals are placed into one of eight categories:

  • Extinct – None left
  • Extinct in the Wild – None are left in the wild, but captive groups exist
  • Critically Endangered – These species are often labeled “probably extinct” and are in imminent danger of extinction
  • Endangered – These species are at high risk of extinction
  • Vulnerable – These species are at moderate risk of extinction
  • Near Threatened – These species are not currently at risk of extinction but are anticipated to be at risk in the near future
  • Least Concern – These species are not currently at risk of extinction
  • Data Deficient – Not enough information

It’s important to note that animals in the Least Concern category are still of concern and should not be ignored, but the threats facing animals in the other categories are currently causing more pressures. The Red List rating scale is often referred to as a “barometer of life”, with each category indicating the amount of pressure on a species pushing it closer toward extinction.

Hosting a Red Listing workshop for the amphibians in Honduras was an exciting and extremely intense process. Of all the countries in Central America, Honduras has the highest number of amphibians that are endemic – or found only in that country, which makes it a very important area for biodiversity. Unfortunately, Honduras doesn’t receive a lot of conservation attention and many of these amphibians are facing the threat of extinction. The Detroit Zoological Society was eager to help this underappreciated hot spot for biodiversity move forward toward understanding the conservation needs of its unique amphibians.

This IUCN assessment of amphibians was the first assessment of all amphibian species in Honduras for more than 15 years, and since the last assessment, 22 new amphibian species were discovered in the country. To assess the animals, the local Honduran amphibian experts were brought together at Universidad Zamarano outside Tegucigulpa for the workshop. With the help of myself, the IUCN facilitators, and two other amphibian experts from the U.S., we all sat down to share data on the 151 species of amphibians in Honduras and determine their IUCN categories. Holding this assessment in country was critical for the participation of these local experts who had intimate knowledge of the species, and who were able to discuss future steps in protecting species of critical need.

We learned a lot through this workshop. Although there were more species assessed in 2019 than in 2002, the overall number of species that are Extinct, Critically Endangered and Endangered all increased. This is especially concerning in this unique area of biodiversity. Because the Red List allows us to assess the specific threats facing the animals, we were able to discuss potential conservation actions needed. At the end of the workshop, a meeting was held with officials from Instituto de Conservaticion Forestal, the governmental institution similar to the U.S. Fish and Wildlife Service, in order to discuss the results of the assessments and what steps could be taken next. Additionally, we hosted a symposium at the Universidad Nacional Automona de Honduras in Tegucigalpa in order to raise awareness about the IUCN workshop and the state of amphibians in the country. More than 150 individuals attended the symposium, including government officials, researchers and students. It was encouraging to see the excitement within the country, especially in so many young students, for the preservation of amphibians. We will continue to evaluate what we’ve learned from this process and determine the next course of action to save these critical species.

– Dr. Ruth Marcec-Greaves is the director of the Detroit Zoo’s National Amphibian Conservation Center.

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.

Notes from the Field: Saving Tree Frogs in Honduras – Part III

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In my previous two blog entries, we examined three critically endangered species of tree frogs in Honduras and shared plans for the Detroit Zoological Society and the Honduras Amphibian Rescue and Conservation Center to begin a head-start program for tadpoles of these species to help increase their populations. If you haven’t had a chance to read these entries, click here and here.

Now, let’s take a peek at what the rescue center facilities look like, and the long-term vision for in-country involvement.

The facilities are currently located in El Jardin Botanico y Centro de Invastigacion Lancetilla, a botanical garden and research center run by Universidad Nacional de Ciencias Forestales. Construction began in 2015 through a collaboration of multiple institutions, including Omaha’s Henry Doorly Zoo and Aquarium, National Autononous University of Honduras, UNACIFOR, Operation Wallacea, Expendiciones y Servicios Ampbientales de Cusuco and the Honduran forestry department. By the spring of 2018, construction was completed and our team inspected the facilities. The team included myself, staff from Omaha’s Henry Doorly Zoo and Aquarium and the rescue center’s co-founder Brandon Greaves. The inspection was to assure that the facilities are ready to provide the best care, biosecurity and welfare for animals that will arrive later in the year.

The ingenious rescue center facilities utilize shipping containers in order to provide housing for the animals. The containers (called “pods”) are ideal for amphibian conservation and care as they are secure, well insulated and easily mobilized should the facility need to be relocated. The pods have full plumbing and electricity, with climate control to suit the needs of our three target species that live in the cool mountain habitats. Each pod is outfitted with a vestibule for caretakers to prepare for a bio-secure entry (which requires clean up and changing clothes).

The pods are outfitted with habitats for up to 1,200 animals (400 from each of the three target species: exquisite spike thumb frog, Cusuco spike thumb frog, and mossy red-eyed tree frog). Water for the animals is treated with reverse osmosis in order to make it safe for amphibians. All water and other waste leaving the pods is cleaned to prevent any contamination to animals of the Lancetilla Botanical Gardens. Live food items (flies, crickets, and other insects) are bred in-house in order to provide ideal nutrition and prevent non-native insect concerns. The individual habitats inside the pods are species specific, catering to the needs of each of the three animals with current, temperature, and substrate. In short…. I would like to live in the pods!

The rescue center facilities are in excellent condition and are ready for animals. As we prepare to bring animals in for head-starting, the rescue team is searching for the perfect local Honduran in order to care for amphibians full time. This individual will train at the Detroit Zoo’s National Amphibian Conservation Center in the care of amphibians. Once head-starting has begun, we will build outreach programs involving local Honduran schools and local researchers. Ultimately, the goal is for the rescue center to be entirely Honduran-run. Our Honduran partners are enthusiastic and we are excited to see their involvement grow.

Honduras is a country that does not receive much assistance in conservation, and the Detroit Zoological Society is proud to be a part of this groundbreaking project saving amphibians in this beautiful nation. We will definitely share more updates as we begin head-starting animals soon!

– Dr. Ruth Marcec is the director of amphibians for the Detroit Zoological Society and oversees the National Amphibian Conservation Center at the Detroit Zoo.

Notes from the Field: Saving Tree Frogs in Honduras – Part II

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As part of the Detroit Zoological Society’s (DZS’s) continuing efforts to save amphibians from extinction, we recently introduced readers of the DZS Blog to three species of endangered frogs that live in the Cusuco National Park in Honduras. These species are at high risk of extinction and we aim to help their populations. If you haven’t had a chance to read my previous blog entry, click here.

Amphibians are facing an extinction crisis, and one of the most tangible causes is disease. In my previous entry, I mentioned the chytrid fungus and how it is causing amphibian deaths globally. Many theories exist as to where chytrid originated and how it spread, but regardless of the answer to those questions, the fungus has now been found in almost every environment all over the world. Removing the fungus from the environment does not seem to be a possibility since it has become so widespread, as this could potentially damage the ecosystem and other lifeforms in it. So, the question becomes: How do we save the frogs?

Frogs are most susceptible to chytrid when they are young – tadpoles and juveniles have the highest death tolls as a result of this fungus. The tadpoles of the three target species we are focusing on in Honduras (the exquisite spike thumb frog, the Cusuco spike thumb frog, and the mossy red-eyed tree frog) are especially sensitive to chytrid. The tadpoles have very strong mouths, which they need to be able to use as a “suction” to hold onto rocks in rapid waters of rivers. Doing so is vital to their survival, and as such, chytrid is particularly damaging to these animals. Chytrid is attracted to keratinized skin cells, which are found in the mouths of tadpoles. The resulting infection causes them to lose function of their mouths, which can cause them to have trouble eating and difficulty with “suction” onto rocks. The loss of this suction can cause tadpoles to be swept downstream into unsafe waters.

Photo by Jon Kolby

This is all devastating; however, we came up with an idea for how we might be able to help.

What if we could remove tadpoles from the stresses of the environment during the stage in which they are most sensitive to chytrid? Using our skills and expertise in caring for amphibians, we might be able to nurture them in a pristine environment. The lack of stress would potentially prevent symptoms of the fungus from appearing. Alternatively, if symptoms did arise, caretakers could treat the fungus to assure survival. Then, when the animals have reached adulthood, they could be returned to the wild.

This method of rearing animals through sensitive stages is called “head-starting”, and is a method frequently used with amphibians. It has shown to be beneficial in instances just like this, where adults survive better than offspring. Long term, the hope is that the increased population from the head-started animals would be enough to booster the population into stability.

Photo by Jon Kolby

The Detroit Zoological Society and the Honduras Amphibian Rescue and Conservation Center are ready to start head-starting animals. Facilities have been built in Honduras in order to provide tadpoles a safe place to live and grow until they are ready for release. In an upcoming entry on the DZS Blog, we will go inside the rescue center’s facilities and show you what the tadpole rearing experience will look like!

– Dr. Ruth Marcec is the director of amphibians for the Detroit Zoological Society and oversees the National Amphibian Conservation Center at the Detroit Zoo.

Notes from the Field: Saving Tree Frogs in Honduras – Part I

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The Detroit Zoological Society is collaborating with the Honduras Amphibian Rescue and Conservation Center to preserve three species of endangered frogs from the cloud forests of the Cusuco National Park in Honduras. The rescue center is an in-country facility that aims to re-populate these three endangered species through programs such as head starting, captive breeding, habitat protection and community outreach.

Amphibians all over the world are suffering extinctions, and the species in the Cusuco National Park are at a particularly high risk. There is a fungal disease, called chytrid, that is causing drastic population declines amphibians globally. Chytrid fungus has been particularly devastating to amphibians that live at higher elevations in the tropics, because the fungus thrives in lower temperatures and high humidity. This fungus likes to live in keratinized skin cells, and because amphibians rely on their skin to breath and exchange nutrients, it can be very deadly. The Cusuco National Park is a protected area that is home to many rare amphibian species who, unfortunately, are subjected to this fungal disease. The Detroit Zoological Society is working with the rescue center to investigate how to help save these animals from extinction.

While there are many species of amphibians in Honduras that need help, we decided to start our mission with three “target species” of critically endangered tree frogs. Once we find the best way to help these species, we can apply what we learned to others locally. These three target species are the exquisite spike thumbed frog (Plectrohyla exquisita), the Cusuco spike thumbed frog (Plectrohyla dasypus), and the mossy red eyed frog (Duellmanohyla soralia). All three of these frogs have been found to have the highest infection rates with chytrid fungus in the Cusuco National Park and are at high risk of extinction. This spring, we conducted fieldwork in Honduras, visiting the natural habitat of the three target species to help gain a better understanding of their behavior. We were able to observe some never-before-seen behaviors of these interesting animals that will help us increase our chances of protecting them.

Before I get too carried away, let me introduce you to the three species!

Photo by Jon Kolby

Exquisite spike thumb frogs are the largest tree frog in the Cusuco National Park at approximately 4 inches long. These frogs are found exclusively in the small protected area of the park, and are listed as Critically Endangered by IUCN. The frogs get their name from the large boney projection that males have on the sides of their thumbs, called a prepollex. It is theorized this special appendage is used for male combat, but combat has not yet been observed in this species. Additionally, the call of these frogs has never been heard (or at least recognized) by human ears.

Photo by Jon Kolby

Cusuco spike thumb frogs also only live in the small protected region of the Cusuco National Park; they are also listed as Critically Endangered. This species also gets its name from a prepollex in the males. Cusuco spike thumb frogs are medium-sized, growing to about 2 inches. Their call is a “quack” noise, similar to a duck. When threatened, these frogs have been observed jumping into leaf litter and burying themselves, which is unusual behavior for tree frogs.

Photo by Jon Kolby

Mossy red-eyed tree frogs are the smallest of the three target species, at a maximum of about 1.5 inches, and are also listed as Critically Endangered. As tadpoles, they have a striking green sheen to them, and they perform an odd behavior. They will flip over on their backs to swim – bellies up – in the rapids of waterfalls. Mossy red-eyed tree frogs can be heard calling with a series of chirps and clicks.

The Detroit Zoological Society and the Honduras Amphibian Rescue and Conservation Center have a plan to save these amazing animals. I’ll be sharing more details about this plan in upcoming blog entries, so stay tuned!

– Dr. Ruth Marcec is the director of amphibians for the Detroit Zoological Society and oversees the National Amphibian Conservation Center at the Detroit Zoo.

Take Part in the Detroit Zoo’s FrogWatch USA Conservation Program

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By late winter and early spring, many people are looking forward to warmer weather, longer days and the fun the coming months will bring. I also look forward to this time of year, not only because of the warmer temperatures, but also the rains of spring and the wonderful creatures that will wake from their long, winter hibernation.

I am, of course, referring to frogs and toads! Here in southeast Michigan, most amphibians depend on rain to help them get “in the mood” for the breeding season. Soon after moving from deep winter to early spring, frogs and toads will make their presence known in full chorus, emitting sounds that also help to protect them from predators.

In 2011, the Detroit Zoological Society began hosting a local FrogWatch USA chapter to collect data on the frogs and toads living in the tri-county area. FrogWatch USA is an amphibian conservation and citizen science program managed by the Association of Zoos & Aquariums (AZA). Citizen science programs teach volunteers to collect data using the same protocol and methods, so all data can be can be counted as part of a scientific research project. One scientist working alone could never collect the amount of information a group of citizen scientists can.

There are currently 144 chapters of FrogWatch USA held throughout the U.S. and data has been collected since 1998. Training classes are primarily taught at AZA institutions, but may also be offered at nature centers, museums or colleges. The project focuses on frogs and toads – both amphibians and some of the most sensitive creatures on the planet. They are also indicators of a wetland’s health – if something toxic or lethal invades the wetlands where they live, they will be the first species to become sick, die or disappear.

All monitoring is done outdoors, so it gives volunteers the opportunity to spend time outside in the wetlands and natural areas of their community. Monitoring helps provide important information from each site, such as the diversity, population size and health of the particular frog or toad species that is present; whether or not there are rare or invasive species in the area, and what the overall health of the wetland is. Knowing what species are present at a sight can even help improve the management and protection of a wetland and all species living there.

Four-hour volunteer training sessions are offered at the Detroit Zoo just prior to the frog and toad breeding season, which is just about to begin. Each session includes:

  • An overview of what amphibians are and why they are valuable to the environment
  • Descriptions and key characteristics of the types of wetlands found in Michigan where frogs and toads may be found
  • Information about the locations of monitoring sites and the ability for participants to register
  • An explanation of the monitoring protocols that volunteers will use in the field
  • Information about how to identify the 14 native Michigan frog and toad species by their breeding calls (Identifying a species by its breeding call is by far the best part of the process. Even though it may be a bit challenging at first, surveying by ear is easy on both the surveyor and the frogs and toads, and it can be a lot of fun.)

Once training is complete, a volunteer’s first priority is to find and register for a site to monitor.  While most volunteers come in already knowing where they want to survey, some do not and we help them find locations in the area. Some sites are in backyards where frogs have been heard for years and others are in wetlands seen from afar and believed to be full of amphibians. Once the nighttime temperature is above 35 degrees Fahrenheit, volunteers can monitor at their sites throughout the FrogWatch season, typically February to August, at most twice a week.

Monitoring must take place at least 30 minutes after sunset. Darkness not only brings more amphibians to life but it also puts the noisy daytime animals, such as birds, to sleep. Whether volunteers have hiked into a wetland via a trail full of crunching leaves or are sitting on their back porch as quiet as can be, everyone must allow at least two minutes for the creatures around them to acclimate to their presence. Immediately after two minutes have passed, volunteers will listen for exactly three minutes to identify each species they hear. At the end of three minutes, the monitoring session is complete.

Monitoring the same site year after year is a great way to keep track of the health of frogs, toads and wetlands. If we lose amphibians, we lose a very precious resource and some really amazing creatures.

I hope you can attend one of the FrogWatch USA training sessions coming up at the end of this month, in February and in March. It is a fun and easy amphibian conservation program that anyone can take part in! Click here for more information: https://detroitzoo.org/press-release/leap-conservation-joining-frogwatch/

– Rebecca Johnson is the associate curator of amphibians for the Detroit Zoological Society and works in the National Amphibian Conservation Center.