Talking Frogs and Amphibians for Leap Day

Thanks for joining me for this CI Live Chat devoted to frogs, and for asking so many fascinating questions. It is great to see such an interest in frogs, my favorite subject!

The cane toad in Australia is a great example of what happens when we introduce something where it doesn’t belong. It was introduced to Australia to try and control crop pests, but unfortunately it also eats native frogs and toads. Because it is not native it would be much better for the ecosystem if it were eradicated. However, there are no known methods of eradicating amphibians safely.

Amphibians are the most threatened group of vertebrates. In addition to traditional threats such as habitat loss, pollution, and introduced species, amphibians are being heavily impacted by more novel threats such as climate change and disease. I believe they are bellwethers of ecosystem health and the fact that they are declining and disappearing is telling us something important about the state of the environment. I therefore believe it is important we respond to the challenge of trying to save them.

Frogs only really interact during mating season when the males of some species become territorial and may even fight to get the females. Some species also communicate in other ways such as arm waving. Frogs also respond to calling but only from their own species. In response to your question about whether they respond to music, they may respond to play-back calls of their species but are unlikely to respond to music or calls of other species.

So there is a global decline of amphibian species on all continents on which they occur. Certain species are particularly affected especially those at high elevations. The most dramatic declines recently have been seen in Central America and Australia. And up to 165 species are thought to have gone extinct. Therefore, while there are some characteristics that seem to make frogs more vulnerable, the decline and extinction is widespread.

Amphibians generally have relatively small ranges and are typically tied to freshwater. This makes them very sensitive to climate change because they often have no where to go. They generally have distinct breeding seasons that are triggered by weather. Climate change will disrupt these breeding seasons. Because of their dependence on water, areas that become drier because of climate change will negatively impact amphibians. And lastly, studies have shown that changes in the climate can make amphibians more susceptible to a deadly fungus.

Amphibians have semi-permeable skin that allows them to breathe. As a result they are very susceptible to pollution and to changes in their environment because they have to keep their skin moist to prevent them from drying out. They are also susceptible to disease, such as fungus. A recent outbreak of a fungal disease has caused amphibians to decline worldwide and changes in the environment and in the climate may alter the way in which the disease affects frogs and make them more vulnerable.

A disease caused by a chytrid fungus has been spreading throughout amphibian populations across the world. It is unclear where this originated but some believe it came from a species in Africa that was commonly used for pregnancy testing in humans. It causes rapid decline of species or certain populations of species and its believed to have resulted in species extinctions. It is particularly alarming because it has caused declines and extinctions even in protected areas. Since its discovery within the last decade, much research has been devoted to learning more about the causes of the disease and its impact on amphibians. Currently there is no way of mitigating the impact of the disease in the wild and the only way we can prevent the almost certain extinction of some species is to collect them and keep them in captivity. We can treat the disease in captivity, but not in the wild.

Lots of good questions, Deepa! Amphibians have fairly good eyesight and can see in color. They are favorite food for many animals and therefore are designed to keep a lookout for potential predators. This is why their eyes are at the side of the head and many species have 360-degree vision. So they can sit motionless and keep an eye out for predators approaching from any angle. When they swallow they withdraw their eyeballs into their head, so yes, it does impede their vision when they swallow but only momentarily.

They do learn from experience. But most of this learning is through evolution and is therefore passed on to the next generation. For instance, amphibians can avoid laying eggs in pools with predators because instinct tells them so.

I am not aware of any studies that have shown that frogs can learn from experience within their lifetime.

As it happens, Madagascar is one of the few places on Earth where the fungus has not been detected in amphibians. This is both good news and bad news because it suggests that catastrophe could strike if the disease makes it over to Madagascar. Evidence suggests that the fungus that infects amphibians throughout the world may have a single origin. It is highly likely that it has been spread by humans. However, once in an area, it is unclear how it spreads. In Central America, it has been shown to spread 28 km per year southwards. Theories include being carried by birds, by insects, or by direct contact between frogs themselves.

That’s a tricky one. Evidence from Costa Rica and Australia indicates a very close interaction between climate change and disease. It may be that a change in climate makes conditions more favorable for the disease or the changing climate could make frogs more susceptible to the impact of the disease. So there’s definitely a link and research is continuing to uncover the interaction and how it differs from one place to the other.

My favorite frog is the midwife toad of Mallorca. It’s a fascinating species because the males carry the eggs on their back legs for about a month after mating. They then drop the tadpoles into a pool of water when they hatch. It's also my favorite because I studied it for three years.

Sadly, I think the chances of your frog having survived are slim. While some species of frog can withstand freezing (such as the wood frog) the bullfrog cannot. If it was frozen solid, I would say it was dead. Sorry. :(

Captive breeding is a controversial conservation tool. I don’t think it will be accepted by all governments. I also believe that it may help us to prevent imminent extinctions of some species but it is not always the appropriate conservation tool. Habitat loss remains a huge threat to the survival of amphibians and efforts to protect critical habitats must be central to any amphibian conservation strategy. Captive breeding efforts must be tied in to longer term strategies that will include plans to reintroduce the animals into the wild.

This certainly is a consideration if only a small number of amphibians can be collected and bred. We did a study where we showed that over prolonged periods of captive breeding, amphibians can lose their ability to respond to predators. Such changes may affect their chances of survival once they are reintroduced into the wild.

Fun question. Frogs use a number of cues to oriente themselves. They have a remarkable ability to return to breeding ponds year after year. It is still a bit of a mystery how they manage to do this, but it's clear that if a frog is set on going in one direction it's very hard to persuade them otherwise.

In some areas when roads are built in the line of annual frog migration, it can cause great problems because the frogs are so determined to get to their breeding ponds that they cross the roads and often get squished.

I very much doubt that amphibians will be extinct by 2010. I think there is a risk that we will have lost a significant portion of amphibians by then, but it would be alarmist to say they will be completely extinct by this date.

Amongst all the bad news, there are also good news stories. We have managed to successfully protect some habitat that represents the last remaining habitat for several species. In addition, new species are being discovered, reminding us that there are many species out there that we don’t even know about yet. To me, these positive stories are enough to keep me optimistic and to make me believe that our efforts are worthwhile and that we can make a difference.

At CI, we are striving to protect some of the most critical habitats for amphibians by working through local partners around the world. Specifically, we recently helped a local NGO purchase and protect an area that was slated for development that held the last population of six species of amphibians.

We also house the Amphibians Specialist Group of the World Conservation Union (IUCN), which comprises some 600 members in over 40 countries. We are tyring to coordinate a global strategy to amphibian conservation to leverage resources and steer them to the places where they are most needed. This is typically in developing countries.

Because it’s easier than saying squawk!

Let's see. It's hard to tell people they shouldn't eat frogs when they rely on these creatures for protein. The best we can do is to educate people about which species are endangered versus which species might be better to eat, where the frogs they eat are coming from, etc. In some cases, frogs can be farmed to provide protein for consumption; however, it's very important that the frogs that are farmed are native species. Because inevitably frogs escape, and breeding non-native species usually links to establishment of exotic frogs.

There is legislation which protects some species from being collected or eaten, but this is only effective if it is enforced. Again, the enforcement relies on education and raising awareness.

I would recommend to anybody wishing to create amphibian-friendly habitats to visit partners in amphibian and reptile conservation at www.parcplace.org. They have excellent resources and guidelines for creating amphibian-friendly habitats in the U.S.

We are doing our best to present this to the Senate and the world. Unfortunately we are competing with priorities that are deemed more important and it’s hard to grab people’s attention unless it’s something that impacts their everyday lives. The loss of amphibians will impact people’s lives in many ways but I fear people will not appreciate this until it has happened. We will continue our efforts to raise awareness amongst the public and key decision makers who can really make a difference.

Wood frogs are found further north than any other North American amphibian. Their ability to withstand freezing is a mechanism that allows them to survive cold winters in these northerly latitudes. They typically hibernante on the forest floor, and without this ability many would perish.

We can learn a lot about the properties that allow them to resist freezing.

I really like your third question so I’m going to focus on that. Amphibians provide many services to humans. They eat the things we hate such as crop pests and vectors of human diseases (like mosquitoes that carry dengue fever and malaria). They are also a source of many compounds that are useful to people. For instance, a peptide in the skin of some frogs has been found to have potential to cure HIV. Another species of frog raises its young in its stomach. It does this by switching off its digestive juices. The mechanism by which it does this can tell us a lot about how we may treat stomach ulcers. If we lose many more of these species we lose the potential to discover their use to us.

Currently there are around 6,000 known species of amphibian. I believe there are many more thousands to be discovered. There are possibly up to 4,000 or so.

For you, I would recommend getting involved as possible with conservation activities and organizations and gaining the experience and the connections that will make you marketable.

Frogs and toads belong to the same order, which is called the Anura, which are the tailless amphibians. It is true that these can all be called frogs. But toads belong to one family within this order. The difference is very subtle and is related to the pelvic bone, which means toads usually hop or walk, while frogs leap. If you find an amphibian with a dry, warty skin, it is most probably a toad.

There are many local initiatives that are doing important work to monitor amphibian populations and raise awareness. I would suggest checking out Frog Watch USA or the Amphibian and Reptile Monitoring Initiative. Also, keep posted on on-going activities through the CI website and at www.amphibians.org, which publishes a bi-monthly newsletter.

How long is a piece of string? It's pretty subjective, I'll admit.

That sounds like a pretty scary newt! Actually amphibians defend themselves either by being toxic, in which case they are generally brightly colored to advertise the fact, or they camouflage themselves. They sometimes make a noise when startled. But that typically wouldn’t be very scary. And it’s more like a squeak than a roar. It sounds like you may have discovered a new species, Melanie.

It is fantastic to see such interest in frogs leading up to Leap Day! But remember, frogs are not JUST for Leap Day - it is equally important that we don’t forget about them after this week. I hope you will all be inspired to take a more active interest in the weird and wonderful world of amphibians and get involved in a local project to help monitor and protect those living near you. It is up to us to protect these incredible creatures over the coming weeks, months, and years and ensure that future generations will also have the chance to enjoy them.