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.

Notes from the Field: Mitigating Human-Bear Conflicts in Armenia

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

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

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

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

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

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

Notes from the Field – The Struggle for Life in Antarctica

As soon as I arrived in Antarctica I began observing penguin behavior. After working in animal care and observing zoo penguins for more than two decades, this comes naturally to me – it’s what I do. I not only wanted to develop a better understanding of how penguins exist in their natural environment, but I also wanted to glean any information that would benefit the penguins that live at the Detroit Zoo. My first glimpse of penguins was on the shoreline of King George Island before we boarded the Ocean Nova. I was thrilled to see two chinstrap penguins that came ashore, presumably to rest after foraging at sea. As the ship made its way through the Shetland Islands towards the Weddell Sea, I began seeing small groups of penguins porpoising through the waves. Their torpedo-like bodies are well designed to travel efficiently for what are sometimes great distances in search of food for themselves and their hungry chicks.

 

Thereafter, we visited penguin colonies daily, most of which numbered in the thousands. It was the height of the breeding season and the islands and Peninsula were teeming with birdlife. The Adelie penguin chicks were the first to hatch and most were too large to brood under their parents. They formed small groups, or crèches, which provide protection from skuas and southern giant petrels that were always nearby looking for meals for their own growing chicks. Ravenous penguin chicks were frantically chasing weary parents down incredibly high rocky slopes and across rocky beaches, only stopping when the parents went out to sea. At this age, penguin chicks are only fed once or twice daily as their parents need to make longer trips to find food. When they finally return with full bellies, the chase begins again. The most vigorous chicks will get the largest meal and will ultimately thrive.

A visit to a gentoo colony made the struggle for life very apparent. There were numerous skuas present, more than I had observed at any penguin colony thus far. The later-hatching gentoo chicks were still being brooded by their parents and many were just starting to crèche. They are most vulnerable during this time when both parents must spend more time at sea and can no longer guard them. I was struck by this proximity of predator and prey. Although they seemed to be coexisting somewhat peacefully, it became apparent that the skuas were constantly watching for any sign of vulnerability. I began noticing obvious signs of this.

There is also danger at sea. Leopard seals will typically linger just offshore of penguin colonies during the breeding season looking for an easy meal. Fledgling penguins are especially vulnerable as they venture out to sea for the first time, unaware of what lies ahead. I observed a group of loafing Adelie penguins sharing an ice floe with a leopard seal that was resting just a few feet away – a seemingly peaceful coexistence that could and would change at a moment’s notice. I began to not only see the struggle for life here, but feel it as well.

I have read much literature about wild penguins and the Antarctic environment over the years, but the knowledge that I gained is something that could only be experienced firsthand. I returned home with a much greater understanding of the plight of these wild penguins, and an even greater sense of resolve and satisfaction in knowing that our resident penguins have lives that include great care and welfare, and without the struggle for life.

– Jessica Jozwiak is a bird department supervisor for the Detroit Zoological Society.

Notes from the Field: To the Moon and Back

Hello from the U.S. Palmer Station! The weather has been behaving and we were able to have a very productive week. Because of the warmer temperatures in Antarctica this time of year, some long-distance travelers from the north came to visit us – a group of more than 100 arctic terns have made their way down for the summer.

The arctic tern is an incredible bird that only weighs as much as a small apple yet it migrates farther than any animal on Earth. They breed in the Arctic during the northern summer and they travel to the Antarctic for the austral summer to feed in the rich waters of the Southern Ocean. They will travel some 45,000 miles every year and may live for decades. This bird lives a full life; it flies the distance to the moon three times over. It is absolutely inspiring watching these weary travelers make it down here, knowing they were at the top of the world just a few months ago.

Back in Michigan, the Detroit Zoological Society helps conserve two different species of tern – black terns and common terns. The DZS has worked with other agencies to develop and maintain a new nesting site for common terns, which have become quite uncommon along the Detroit River over the last 50 years. We are also working with the National Audubon Society and the Michigan Department of Natural Resources, looking at nesting success of black terns in the St. Clair Flats. Black terns are suffering population decline across their range and we are committed to learning more about their life history in order to reverse this trend and protect the species.

Besides the arctic terns, we have been very busy studying the local birdlife. The Adelie penguin colonies seem to show some variation with regard to what stage of development the chicks are in. Some of the chicks are getting huge and the nests are getting crowded as many proud parents have two chicks growing well. That being said, the noise level continues to climb and the colonies are starting to become messy! It does appear that the chicks pick up bad habits at a very young age (stealing rocks from the neighbors).

The brown skua chicks continue to hatch and grow as well. We have been measuring their beaks and routinely weighing them, tracking their growth. The parents can be a little feisty, but overall they tolerate us well. The chicks are beginning to run around and explore, which can make it tougher for us to find them.

As the days of this incredible journey continue to pass, the northern hemisphere has started to tilt back toward the sun and our days are shortening a touch. It’s still pretty much always light out, but it’s getting slightly easier to see the sun set.

Have a great week; I will report back soon!

– Matthew Porter is a bird department zookeeper for the Detroit Zoological Society and is spending the next few months at the U.S. Palmer Station in Antarctica for a rare and extraordinary scientific opportunity to assist a field team with penguin research.

Notes from the Field: ‘Iced in’ at the Palmer Station in Antarctica

With the right wind, the harbor can go from totally clear to completely packed with large pieces of ice and glacier chunks within just a few hours, icing us in at the Palmer Station. When this occurs, we have to wait for the winds to change before we can work to clear the ice out. Being stuck at Palmer for a couple days was no problem though; it gave us time to catch up on data and paperwork and we were able to hike to a cove to do some fieldwork with southern giant petrels.

Land travel requires a lot of gear and also snowshoes, which we outfitted ourselves with before walking out into the “backyard” of the Palmer Station. We hiked up to the top of the glacier, where the views were absolutely breathtaking.

We walked around an inlet and back down the glacier over to a couple spits of land where southern giant petrels, Antarctic terns, and kelp gulls can be found. Giant petrels can have a wingspan of almost 7 feet and their eye colors vary from light to very dark, with every individual having its own unique color pattern. Many of these majestic and often very gentle birds have been banded throughout the years, and we were able to retrieve identification numbers from several of them, which will aid in the study of these birds. We were also able to outfit one of the birds with a transmitter to collect data on where the bird is travelling.

Finally, the winds shifted direction and we were able to travel by boat to continue our island fieldwork. We spent a lot of time catching up on censuses of Adelie penguin colonies – much to our excitement, many were full of parents incubating eggs! One humorous mainstay is the elephant seals that hang out around the station. Most mornings when exiting the building, there are multiple elephant seals present, which I’m told isn’t so common from year to year. We have to watch where we walk and keep our distance, giving the proper respect and privacy to all the local wildlife. In Antarctica, there are treaties and conservation acts to follow with regard to viewing wildlife, which is a good reminder of how we should treat all wildlife and wild places, no matter where we are in the world.

Thanks for reading; I will report back soon!

– Matthew Porter is a bird department zookeeper for the Detroit Zoological Society and is spending the next few months at the U.S. Palmer Station in Antarctica for a rare and extraordinary scientific opportunity to assist a field team with penguin research.

Notes from the Field: Antarctica Fieldwork Begins

The first day in the field was an absolute dream come true for me. After an early breakfast and an intense look at the weather, we collected our gear and got dressed for a day of fieldwork. We dressed in layers to protect ourselves from the harsh environment and the potentially soaking boat ride. During my time in Antarctica, we will travel by boat to many islands to study different colonies of birds. The weather can change in a heartbeat, with strong winds bringing rough seas and treacherous ice drifts, so we need to be prepared.

We headed out to a nearby island, which has multiple colonies of Adelie penguins. We tied up the boat and proceeded to count birds and collect data. I was speechless staring at a colony of these penguins and the pure beauty of nature – some birds were working on building nests out of rocks and others already had eggs – Adelie penguins generally lay a clutch of two. It is fascinating watching the birds work on their nests and interact within the colony.

Another bird of note in this region is the brown skua, a good-sized bird that will nest up on rocky ledges around the penguin colony. They often lurk on the edges of the colony waiting for an opportunity to steal eggs. Their strategy works well and they certainly get their fair share of Adelie eggs.

Near another Adelie colony, we spotted a southern elephant seal nursing her pup. There are many southern elephant seals in the area – the females weigh close to a ton while full grown males may weigh as much as 4 or 5 tons! Antarctica is a magical place that surrounds you with beautiful, pristine nature.

Throughout the week we have visited multiple islands surveying the birds and taking data. The conditions have been good with temperatures around freezing, with snow and rain mixed in. Thankfully the high winds tend to hold off until the evening, allowing us to get our work done. While I’m known at the Detroit Zoo for wearing shorts year-round, here I am wearing pants. What can I say – it’s Antarctica!

Thanks for reading; I will report back soon!

– Matthew Porter is a bird department zookeeper for the Detroit Zoological Society and is spending the next few months at the U.S. Palmer Station in Antarctica for a rare and extraordinary scientific opportunity to assist a field team with penguin research.