This month, we had the opportunity to catch up with Dr. Jonathan Kolby, founder of the Honduras Amphibian Rescue & Conservation Centre (HARCC) 🇭🇳🐸. On a mission to save the world, one frog at a time, Jonathan shared his insights on the global amphibian declines caused by chytrid fungi.
Con Con: What drove your interest in amphibian conservation?
Jonathan: When I was quite young I started volunteering my time doing herpetological field surveys with conservation groups, and when I was 15 years old I had an opportunity to join someone who was doing long-term biodiversity surveys in Hong Kong and China. That was my first time ever doing field work and it got me hooked ever since!
I went back with them and was their field assistant every summer and after doing that for about five years I wanted to start somewhere different. I saw a vacancy announcement for a position with Operation Wallacea who were looking for some help in Honduras. I knew absolutely nothing about Honduras and the species that live there but I thought: ‘You know what, that sounds good. I’ll try that!’
I went there for the first time in 2006 as one of the staff on their team doing a long-term biodiversity survey with the hope that our data could be used to help protect the forest which was under a lot of pressure. I was asked to come back again in 2007 and that was a critical turning point for me! While I was preparing to go back for the second season, I started doing a lot more homework than I had done the first year to really understand what were those species that we were catching. I was reading a lot of the IUCN Red List assessments for some of these frogs, many of which were already listed as Endangered or Critically Endangered, and a lot of them had been reported to be declining, some of them for enigmatic reasons.
At the exact same time, I was able to take a class about amphibian disease monitoring and that’s when I learned about chytrid. I learned how easy it was to sample for chytrid and that it was associated with unknown reasons for decline so I just thought why don’t I see if that’s in this forest as it might be why these frogs are disappearing!
Limosa Harlequin Frog (Atelopus limosus) that tested positive for chytrid (Bd) - note the lesions, skin-shedding and the frog is not attempting to 'right' itself when laying on its back. 📸 Brian Gratwicke
That was really the first time I ever designed my own research project and the results of that summer project showed me that chytrid was everywhere in this forest 🌳. It was highly prevalent in these endangered species that were declining for unknown reasons. I decided to sink my feet in Honduras and see if we could understand what was happening to these frogs. That was the beginning of my crusade to save the frogs in Honduras! 💪
📸 Simone Sbaraglia
ConCon: How does chytrid impact on amphibians and why it is threatening various frog species around the globe?
Jonathan: There are hundreds of different species of chytrid fungi. Most of them are beneficial in the environment but there are a few species that parasitised living animals. There are now two species of chytrid fungi known to attack living amphibians. Most of the focus is on the one that mostly affects frogs which is Batrachochytrium dendrobatidis, but more recently there’s been a second one discovered, Batrachochytrium salamandrivorans, which is specifically attacking salamanders.
📸 Ray Hennessy - Orange and black long-tailed salamander
The chytrid fungus is a highly aquatic pathogen and it basically latches on to an amphibian and starts to burrow under the skin until it goes a few layers down to parts of the tissue that produces keratin. That’s where it sinks its roots and feeds and feeds and reproduces. Once it reproduces, it exudes new spores into the environment that will be carried by the current and will find another tadpole and latch on to that and start the process over.
📸 Brian Gratwicke
The reason it is so bad for amphibians is that their skin structure is so important for the exchange of gases and chemicals! The growth of the fungus in the skin interferes with those processes. It doesn't actually cause much internal damage to the organs but by interfering with the skin it causes things like heart attack and electrolyte imbalance.
ConCon: How are you planning to tackle the chytrid crisis you’ve witnessed in Honduras through the Honduras Amphibian Rescue & Conservation Centre?
Jonathan: There are a handful of other rescue projects around the world that are also trying to save frogs from chytrid. What most of them have done is go to an area where they know the wave of chytrid is about to arrive or has arrived and basically collect as many frogs as they can to save them and protect them in captivity. There are simple veterinary anti-fungal medicines that are effective against chytrid in captivity but the biggest global problem is that most amphibians do not respond to re-exposure the way mammals do. They don’t learn to protect themselves after the first exposure and because of that everyone has been unsuccessful so far in creating any sorts of vaccination method. So while you can protect a species under controlled care, if you put them back in the wild to the same habitat that has chytrid and they get infected again they have no advantage from animals that you’ve never made an effort to protect.
From closely studying the three species that we are focusing on [in Honduras] for so many years across life stages, we think that we found a critical aspect of how to adaptively manage the frogs and allow them to survive in the wild. We know that in the species in Cusuco National Park most of them get exposed to chytrid as tadpoles. Because chytrid is an aquatic pathogen, it’s always in the river and we can’t get rid of it safely, but it doesn't often seem to cause negative effects on the tadpoles. It’s localised in their mouths because that’s the only place a tadpole has keratin.
📸 Jan Van Der Voort
There are some beliefs that this could affect their feeding and nutrition and it probably does to an extent but not merely to the extent it does once they start to transition into baby frogs! Then keratin starts to be produced all over their skin and suddenly it has so much more surface area. At that same time, the frog immune system suppresses itself because it starts growing the organs of an adult frog. That double whammy is the critical weakest link in the system in terms of survival. We believe that most of the frogs that already have infections as tadpoles are dying at that point or shortly after and very few survive to become adults.
The key is, though, that some do survive to become adults! It’s probably genetic but it could just be random chance, nobody has figured that out yet. Regardless of why, the point is that it happens and through radio-tracking we have found that a lot of those adult frogs are able to still live in infected habitats, get exposed and cure themselves. We’ve seen their infections go back and forth from positive to negative and they always maintain it at a very low level whereas in the baby frogs the level of chytrid is sky-high showing that it is causing diseases. So basically, we want to turn the system around. Rather than just focussing on captive breeding, we want to do something called ‘head-starting’ which is working with what nature is already providing but then identifying the weakest link and giving that link an advantage.
For us, the baby frogs and the tadpoles are the weakest links and our plan is to start taking out hundreds of those weak animals every year, bring them to our bio-secured facility where we can care for them under medical attention, cure and manage their chytrid infection, and then raise them until they become adults with their adult immune system. Eventually, we hope to reintroduce every year hundreds of adult healthy frogs right back to where they were collected so that they can rejoin the breeding population and then extract babies over and over again. Our hope is that by doing this, they will then breed more in the wild and produce many more offsprings.
📸 Franco Andreone
We’re not tinkering too much with the system but we are just playing a numbers game. We want to provide nature with a natural selection with a lot more animals to sort through to find those genetically superior animals and prevent extinction during this bottleneck. If we do this long enough, we won’t have to keep doing this forever and the animals can naturally evolve resistance because nature will select for that. Then the population will start to increase without our reintroduction effort.
ConCon: What are you the proudest of having accomplished so far as a conservationist?
Jonathan: In my second chytrid survey in Honduras in 2008, I rediscovered a frog in Cusuco National Park that was declared extinct and looking back that’s what I’m the proudest of! To be able to find a species that was thought to have gone extinct because of chytrid and then to just happen to stumble across is something I’m pretty proud of. But it was luck too though, I won’t take all the credit for it.
I’m also really proud of running the HARCC! Through the rescue programme, my real goal is beyond just protecting these frogs but is also to provide some local empowerment for Honduran scientists in the region. I feel that Honduras does not get nearly the support that they need or deserve for biodiversity conservation compared to other countries in the region. Through the work we’ve been doing with science communication, filmmaking and outreach through our programme I’m quite pleased with how much positive attention we’ve been able to bring to the country and the biodiversity that deserves to be protected there, hopefully inspiring some younger Honduran scientists to become more engaged on the chytrid issue.
They have great biology programmes in school and in college in Honduras but afterwards, it’s often very hard for them to find an opportunity to actually exercise what they want to do. I’m hoping that through our project we can provide some opportunities through internships and employment.
ConCon: You are a keen science communicator, why is that so important to you?
Jonathan: When I started seeing how effective [social media and science communication] were in engaging people it opened my eyes! 👀 I needed to see if I could use this to talk to the general public who didn't already have an interest in what I did. Experimenting with that really got me engaged in the psychological aspect of how to change behaviour or open people’s eyes to things that they normally don’t have time for or don't think are important.
📸 Scott Trageser
I’ve come to think that this is not only interesting but a responsibility! It requires a lot of thoughts and time to be effective at communicating science with the public so I wouldn't say that everyone should be doing it, but everyone should be thinking about it.
It’s also made me really interested in using films as a vehicle for education and outreach 🎥. A couple of years ago a woman from England, Katie Garrett, reached out to me from reading something that I had written and she asked me if we had any interest or need for a little video clip to tell people about what we were doing. After talking with her, we decided to meet up in the rainforest and she helped us shoot a video for a crowdfunding campaign that we did and then from that, we decided to make a film for a festival. That whole process of working with her even more deeply opened my eyes about using different ways of communication to reach different people!
ConCon: Are you optimistic for the future of amphibians and the fight against chytrid?
Jonathan: I’m a naturally optimistic person! Seriously thinking about amphibians, what they’re facing and the challenges and the realities of it, I am optimistic that there are some species that we can save. There is a lot that can be done right now and we can feasibly save a lot of species from extinction. We don't have a lot of time to keep waiting but I think we definitely need a more coordinated global effort! I see a lot of local and regional efforts that are phenomenal but there is a lot that we can learn from each other and that’s something that I’m hoping to start a movement in the near future.
We’re pretty confident that the reason we are in this situation [with the chytrid spread] is due to the lack of global regulations on these diseases moving through the wildlife trade. It’s just unfortunate that frogs were the first group of animals to suffer from this but it doesn't mean that it is restricted to frogs. It took us decades to understand that chytrid was behind a lot of the amphibian declines we were observing so it is my hope that we can learn more about how chytrid fungi are spreading and apply this information to help the next group of animals to respond faster and prevent it from getting to this extent.
📸 Scott Trageser