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

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.

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

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

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

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.

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.

Education: Community and Conservation

Four teenaged girls recently assisted the Detroit Zoological Society (DZS) with our amphibian conservation efforts by pairing up with staff members to build mudpuppy shelters at the Detroit Zoo’s Ford Education Center. These young ladies were from Oakland County’s Children’s Village, a residential treatment and detention center for youth. The DZS began a partnership with Children’s Village in 2009 to instill respect and reverence for wildlife and wild places within the hearts of these teenagers. The program expanded in 2016 to offer off-site community service opportunities for the residents.

Mudpuppy shelters are an important piece of our ongoing conservation work as we monitor the population of these aquatic amphibians on the shorelines of the Detroit River and the inland lakes of Belle Isle. Mudpuppies are indicators of water quality; they cannot survive in polluted or contaminated water, so their presence is a sign of a healthy aquatic ecosystem.

DZS amphibian staff provided the specifications for the height, width and depth of these cement structures, as well as the materials to make them. The young ladies worked in pairs with DZS staff members, donning thick gloves and using wire cutters to trim heavy-duty wire mesh, before folding and binding it to form the bottom of the shelter. They then layered the cement over the wire mesh and built it into a solid, smooth floor and walls. Separate pieces of wire mesh were then cut to size and layered with the cement mixture to create roofs for the shelter.

Once the weather warms up, the shelters will be placed in the water around Belle Isle in hopes that mudpuppies will find them a desirable place to lay their eggs. They tend to lay their eggs under rocks in their natural habitat, which makes it difficult for researchers to locate the eggs without potentially disturbing them by having to move rocks. With the easy-to-remove roof on these homemade shelters, mudpuppies could lay their eggs inside and DZS staff would be able to lift the top and easily check on the eggs without disturbing them.

The young ladies who helped build the shelters will join us down on Belle Isle in the coming weeks to place them in the water. They will have the opportunity to work alongside DZS amphibian and education staff to record weather, water quality and shelter placement as well as check on previously placed shelters.

These teens are facing many challenges in their lives and working alongside scientists in the field offers them the chance to explore careers they may not have otherwise known about or considered. It is an opportunity for them to try a new experience, build skills and understanding, and give back to the community through conservation.

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