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.

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

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.

Amphibian Conservation: Wyoming Toads Prepare for Breeding

A pair of small gold eyes peers out from under a mass of sphagnum moss. In a day or two, this warty creature will complete its climb out from the depths of the sandy soil where he has spent the last 30 days sleeping and “chilling” at a cool 38 degrees. Along with seven other individuals of this species, he will awaken due to an increase in temperature and light. By the time the temperature reaches 74 degrees, he will have completely removed himself from the soil and be sitting atop it, hopefully alongside his companion, a slightly larger female. In the week that follows, events these two small cold-blooded creatures will go through could lead to producing thousands of their species in a matter of hours due to their “explosive” nature.

The Wyoming toad (Anaxyrus baxteri) is one of North America’s most endangered species and one of the amphibians we work with as part of a Species Survival Plan (SSP) at the Detroit Zoo’s National Amphibian Conservation Center.  This toad’s wild populations began declining in the 1970s, and by the 1980s was listed as an Endangered Species by the International Union for the Conservation of Nature (IUCN). Possible causes for the population decline are use of aerial pesticides to eliminate mosquitoes, habitat manipulation, and disease in the form of the amphibian chytrid fungus. Realizing a decline was occurring, the last remaining toads were collected and by 1994, all remaining wild-born Wyoming toads were believed to be entirely in captivity. The IUCN now describes the Wyoming toad as extinct in the wild, meaning any toad currently found in the wild has come from captive breeding, in which the Detroit Zoological Society (DZS) has been actively involved.

The Wyoming toad SSP is managed by the Association of Zoos and Aquariums (AZA). The DZS has been a member of this conservation program since 1995 and since 2001 has sent a total of 6,505 tadpoles and toadlets to the wild. All Wyoming toads are the responsibility of the U.S. Fish and Wildlife Service (USFWS), so members of the AZA work closely with them to follow all USFWS permit guidelines for keeping them in captivity. The goal of any captive breeding program is to produce healthy offspring for release into the wild with the goal of rebuilding them into a self-sustaining population. Each toad in captivity is identified and tracked, which helps to pair toads that will produce the most genetically diverse and healthy offspring. Breeding pairs of toads are chosen almost a year in advance so toads have plenty of time to move from one zoo to another to create the breeding pairs.

Although not as well known as Jabari and Kivuli, the giraffe couple at the Detroit Zoo, Wyoming toads Butler and Beverly are a very important couple of toads. They are part of a “bio-secure” population and will never be seen by the public, which ensures they will not accidentally release diseases, known or unknown, into the wild via their offspring. They are held with four other pairs of Wyoming toads in a special room away from all other amphibians, so they will remain free of diseases that could otherwise be found in species not native to the western region of North America.

At the AZA’s recommendation, Butler arrived at the Detroit Zoo last October to be paired with Beverly, who arrived in 2012. Both are now 3 years old, which is about middle aged for a Wyoming toad. In early April, they were placed together into a thermostat-controlled “hibernaculum”, which is used to cool the toads, simulating the hibernation period a wild Wyoming toad would go through during the winter. The toads are kept cooled for about a month to help prepare them for breeding; eggs or sperms may develop and mature as a result of this cooling. The toads are given plenty of sandy soil to bury down into and sleep in just as they would have in the wild, and the Zoo’s animal care staff checks in on them weekly to make sure they are doing well.

At the end of May, the temperature in the hibernaculum will be increased to 70 degrees Fahrenheit and the toads will begin to awaken. Once they have climbed out from the soil, we will place them back into regular husbandry for a few days where they will continue to warm up and eat. Recordings of male toads calling are played during this time to condition toads further for breeding. Within a few days of emerging from hibernation, Butler and Beverly will be placed into a breeding chamber with 2-3 inches of water. The pair will hopefully go into “amplexus” within a few hours, which happens when the male positions himself on top of the female using his front legs and squeezes her, encouraging her to lay eggs. He fertilizes the eggs as she lays them, usually in the dark, overnight. Butler and Beverly should lay thousands of eggs, which is typical of toad species. Described as “explosive breeders”, the more eggs they can lay the better the chance offspring have of surviving the elements, diseases and predators. Since this is a captive breeding, we can help the thousands of eggs that Butler and Beverly produce survive into strong, healthy tadpoles.

Approximately two to three weeks after eggs have hatched into thousands of hungry tadpoles, arrangements are made with the USFWS to ship the tadpoles to Wyoming, where they will be released into protected wetlands. These tadpoles will add to those previously produced in captivity sent yearly by the zoos that participate in this program and the USFWS.

The wetlands are monitored during the spring and summer as part of yearly field surveys done to track the health and population of the toads. This year we hope that Butler, Beverly and the three other pairs of Wyoming toads at the Detroit Zoo are able to contribute thousands of healthy tadpoles to the wild population.

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

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: Species in Crisis

Let’s focus our attention on the smallest residents living at the Detroit Zoo: amphibians. No other class of vertebrates has the ability to adapt and evolve as quickly in our ever-changing planet as amphibians. They have used every reproductive strategy and developed life stages influenced by environmental factors; they can be colorful, camouflaged and cryptic, regenerate limbs, and have been on Earth for the last 200 million years.

Marcy Blog 4

Currently, amphibians are the most threatened group of animals in the world with 40 percent of all species at risk. This crisis is considered the greatest extinction event in history; it’s also the Earth’s sixth mass biological extinction. While previous mass extinctions have been driven by natural planetary transformations or catastrophic asteroid strikes, the current die-off can be associated directly with human activity. This epoch started when human activities began having a significant impact on the Earth’s ecosystems.

The Detroit Zoological Society (DZS) participates in Global Assessments, which provide a comprehensive inventory of the conservation status of biological species as well as a critical dataset for evaluating the health of key elements of biodiversity and identifying threats to their survival. Newly described species emerge yet extinctions are occurring at an even faster rate. Climate change is the most dramatic cause of declines, and it affects amphibians both directly and indirectly, as reproduction is dependent on temperatures and seasonal transitions. Low pond levels expose embryos to more ultra violet (UV) light and UVB radiation is harmful to many species. The shorter periods and earlier opportunities for breeding ultimately reduce the chances of success. Amphibians are also dependent upon water, which makes them vulnerable to desecration when ponds dry too quickly. But since amphibians rely on the environment, they also are excellent storytellers. They can help us determine where pollutants are and if there is misuse of habitat.

When the National Amphibian Conservation Center (NACC) opened at the Detroit Zoo in 2001, it was the first major facility dedicated entirely to conserving and exhibiting amphibians. The award-winning, state-of-the-art amphibian center is home to a spectacular diversity of frogs, toads, salamanders, newts and caecilians, many of which are the subjects of field research and part of cooperative management programs called Species Survival Plans (SSP). Amphibians selected for an SSP are generally threatened, endangered and sometimes even extinct in the wild. The DZS is actively involved in many of these programs, including for the Wyoming toad, Puerto Rican crested toad, Panamanian golden frog, crawfish frog and Mississippi gopher frog. Some amphibians bred at the Detroit Zoo have been released into the wild to boost endangered populations, and others require us maintaining a “captive assurance population” because due to factors in the wild, they cannot be released just yet. When it’s safe for these species to return to their native homes, we have a population ready to release. We have specially designed, bio-secure rooms that can hold each of these species so they won’t be exposed to other amphibians or anything else that may be harmful when they are released.

In addition to maintaining our captive amphibian population and our efforts in cooperative breeding programs, DZS staff participates in several field projects and research programs, offers citizen science training and provides support for wildlife rescues, including those from the exotic pet trade.

– Marcy Sieggreen is the curator of amphibians for the Detroit Zoological Society and oversees the National Amphibian Conservation Center at the Detroit Zoo.

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 – Peru

Detroit Zoological Society Curator of Amphibians Marcy Sieggreen 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.

Hola mi amigas y amigos!

It has been nearly over a week since my last post and a lot has happened. We have seen several species of frogs at night. There has not been much activity during the day but it is still important to look and make note of what is or is not seen. We have travelled to all of the islands that we usually observe that are surrounded by the Napo but have also found another uninhabited island that is underwater during most of the year.

Marcy - Peru 2      Marcy - Peru

What a pleasure it was to jump out off the boat and find hard sand (like what we know as a beach) with marine toads everywhere. Some of you may have heard that these toads are now found in several places in the world and are considered invasive species, making them a nuisance. Here in South America, they are native and an important part of the ecosystem. Since I had not seen many on this trip, I had a growing concern. The island also had a bog that was home to several tree frogs. There were no species I had not seen before but a positive confirmation that species I would expect to see I had.

I have seen many caimans, snakes and most recently a mammal, which I believed to be a Paca. Animals this size (about the size of a 30 lb dog) is not frequently seen and is very fast. Although amphibians are the most fun to track down, seeing other wildlife is always a treat.

This upcoming week, I will be working with our Amphibian Protectors Club on an overnight observation through a small portion of the rainforest and along the canopy walkway.  My colleagues from the Detroit Zoological Society’s education department are taking time out from their schedule to join us. We are hoping to be able to see lots of animals and document our findings back at the research station. Buenos noches!

– Marcy Sieggreen