Yesterday while shopping at the mall, I noticed that some stores had already begun putting up holiday decorations. The racks were filled with sweaters and down coats. We humans (at least in the northeast U.S.) are preparing for winter. But what about our amphibian friends? How do they prepare for winter? After all, frogs would seem vulnerable to extreme cold with their thin skins and their need to constantly stay moist.
Actually, we don’t need to worry about the frogs. They are well-equipped to deal with the cold weather, even with Arctic temperatures.
Frogs are ectothermic, which means that they rely on their environment to regulate their body temperature. Birds and mammals, including humans, are endotherms. We generate heat chemically and internally by breaking down food. The bodies of ectotherms reflect the air, ground, and water temperatures around them. One advantage that ectotherms have over mammals is that they can survive for long periods without eating.
In the fall, frogs first need to find a place to make their winter home, a living space called a hibernaculum that will protect them from weather extremes and from predators. The frog then “sleeps” away the winter by slowing down its metabolism. When spring arrives, it wakes up and leaves the hibernaculum, immediately ready for mating and eating.
Aquatic frogsand toads such as the leopard frog and American bullfrog usually hibernate underwater in streambeds or on pond bottoms. Because aquatic frogs need oxygen, they lie just above the mud, or only partially buried in the mud, so they are near the oxygen-rich water. They may even occasionally slowly swim around.
Terrestrial frogs and toads typically hibernate on land. Those frogs and toads that are good diggers like the American toads burrow deep into the soil, safely below the frost line. Other frogs, such as the wood frog and the spring peeper, aren’t good diggers and so must scout out their winter homes in deep cracks and crevices in logs or rocks, or they might dig down into the leaf litter.
These frozen peepers and wood frogs might look dead; their hearts have actually stopped beating. But the partially frozen frogs aren’t dead. Instead, they have a kind of natural anti-freeze in their bodies. Ice crystals form in their organs and body cavity, but a high concentration of glucose in the frogs’ vital organs prevents freezing. When spring approaches and its hibernaculum warms up above freezing, a frog’s frozen body will thaw, and it will come back to life.
As you go about preparing for winter, think of the frogs with their amazing adaptations for survival, safe in their winter homes, waiting for spring.
Here’s a video from YouTube about the hibernation of a wood frog. It’s pretty amazing—take a look!
This is a partial repost of an earlier post from December 2010. Most of the information from the post came from an article in Scientific American, How Do Frogs Survive the Winter?by Rick Emmer.
One of our first posts at Frogs Are Green was about the coqui, a frog native to Puerto Rico, where it exists alongside several other species of Eleutherodactylus frogs and where a biological balance is maintained. It was introduced to Hawaii in the mid- to late 1990s and has no competitors so it has spread unchecked and is considered an invasive species. But our guest author, Sydney Ross Singer, a medical anthropologist, biologist, and author living on the Big Island of Hawaii, would like us to look at this problem from a new perspective. Perhaps this “alien” species should not be rejected and destroyed but welcomed.
Besides being beautiful, fascinating, a source of medicinal substances, and essential for healthy ecosystem function, frogs are canaries in the environmental coal mine. They are sensitive to pollution and climate change. And their numbers are declining at extinction rates.
That’s bad news for the rest of us living in the coal mine. Clearly, we need to change our ways.
But change is difficult for a culture to accept. Until people are dying at the rate of frogs, nothing will alter our bad cultural behaviors.
So the next best thing to do is try saving the frogs. We may not be able to stop pesticide and herbicide use, or end the deforestation and development of wild areas, or stop all the industries and lifestyles that contribute to climate change. But we can catch frogs where they are declining and find new, healthier places for them to live.
We might not have the political and economic clout to stop multinational corporations from exploiting and altering the world’s environments. But we can help refugee species flee the destruction and avoid extinction.
There are places on the planet that can serve as sanctuaries for these refugees. One place, in particular, stands out as one of the best – Hawaii.
If you move frogs from one place to another that already has frogs, the immigrants will compete with the natives, and you can possibly lose native frog populations. Hawaii, however, has no native frogs, or any native reptiles, amphibians, land snakes, or lizards. What better place to introduce frogs? Lots of insect pests to eat, warm and humid conditions, and few predators. If we wanted a sanctuary for endangered and threatened frogs, this is the place.
But wait. Can we just move a species from one part of the planet to another? Won’t it become invasive and cause damage?
It is this question that is keeping frogs from finding new homes. According to current trends in environmental thinking, species “belong” where they are “native.” You’re not supposed to move them to places where they “don’t belong.” When it comes to frogs, the Hawaii government has said they clearly “don’t belong.”
Of course, there are already frogs and toads in Hawaii, which were brought by environmental managers for insect control decades ago. Back then species were introduced deliberately to enhance biodiversity and provide needed environmental services, such as pest control, or to serve as a food source. The environment was seen as a garden for us to plant and inhabit as we saw fit.
That has all changed. Now the goal of managers is to kill introduced species in order to preserve and restore native ecosystems as they had existed prior to western contact centuries ago. They won’t get rid of the people, or the agriculture, or the chemical spraying, or the bulldozing, or the deforestation, or the development, or the intercontinental shipping, or the industries and energy policies that help cause climate change. It’s hard to change these aspects of the culture. But you sure can kill things that “don’t belong.”
What was called “exotic” or “immigrant” is now called “alien” or “invasive.” We have gone from an open immigration policy to a bio-xenophobia.
When coqui tree frogs accidentally arrived in Hawaii with shipments of plants from Florida or Puerto Rico, the response was ballistic. The mayor of Hawaii declared a state of emergency. Scientists feared the sky was falling, and that the coquis, which eat lots of insects, would decimate the insect population to the point of starving all other insectivorous creatures. The sound of the frogs, a two-toned “ko-KEE”, was described as a “shrill shriek” guaranteed to keep everyone awake at night, run down property values, and drive away tourists.
Ironically, this same coqui frog is the national animal of Puerto Rico, its native land. In fact, Puerto Ricans love this frog and its chirping sound so much that it is honored in local folklore. People describe the nighttime sound of the coqui as soothing and necessary for sleep, and Puerto Rican travelers often bring recordings of coquis with them when away from home to help them sleep.
Puerto Rico has numerous species of coqui frogs, many of which are now extinct or threatened. Unfortunately, frog numbers are declining because of fungal infections, development, climate change, and pesticide and herbicide use. So you can imagine how angry and upset Puerto Ricans were when Hawaii announced its Frog War to eradicate the newly arrived coquis.
Over the past 10 years, millions of dollars have been spent in Hawaii trying to kill coquis. And despite wide cost-saving cuts in government spending, there is still money to kill coquis.
At first, they tried an experiment to kill coquis with concentrated caffeine, giving the frogs a heart attack. A special emergency exemption was needed from the EPA to allow this spraying of caffeine into the environment. It’s impact on humans, pets, plants, lizards, and other non-target species was unknown, or what it would do once it entered the groundwater and flowed to the oceans. Chemical warfare suits were needed by applicators to prevent exposure to the highly dangerous caffeine, which was at concentrations 100 times that of coffee. There is no antidote for caffeine poisoning.
When the caffeine experiment proved untenable and too dangerous, citric acid was encouraged as a frogicide. Sprayers soaked the forests with acid, sometimes sprayed from helicopters, to drench the tiny frogs and burn them to death. Of course, this also killed plants and other critters, such as lizards. But since lizards are non-native, nobody in the government cared.
But citric acid is expensive. So another experiment was tried, using hydrated lime to burn the frogs. This caustic chemical can also cause irreversible eye and lung damage to people and pets on contact, so another emergency exemption was needed from the EPA to experiment with it. As it turned out, the hydrated lime didn’t work very well, and it killed lots of plants.
So the University of Hawaii experimented on developing a frog disease to unleash on the frogs. They tried a fungus to infect the frogs, the same one killing frogs elsewhere in the world. They realized the fungus might also kill the geckos, skinks, anoles, and other lizards, as well as the toads. But since none are native to Hawaii, none of the eradicators cared. In fact, destroying all the lizards and toads would be considered a plus. The coqui frogs, however, survived the fungus, so it was never released wide scale.
By now you may wonder how people can get away with this abuse of frogs. Aren’t there laws protecting animals from this type of cruelty?
There are. So to get around the laws the Hawaii legislature passed a law defining the coqui as a “pest.” Pest species are exempted from humane laws.
This moral depravity reached its zenith in 2007, with a planned Coqui Bounty Hunter contest to be held by public schools on the Big Island. Schools instructed students to kill coquis, either by burning them with acid, cooking them alive, or freezing them. The school with the most “kills” would receive a prize — the violent video games Playstation 3 and Xbox. The contest was canceled once it was pointed out to the schools that students are supposed to receive humane, not inhumane, education.
Despite the eradication attempts, the frogs spread. Actually, sometimes they spread because of these attempts, since coquis try leaving areas disturbed by spraying. An interisland quarantine on the coqui still exists, requiring all plant nurseries to treat plants with hot water, proven lethal to coquis and their eggs, prior to transport to other islands. But the coquis seem to frequently survive that, too.
So here is the irony. Frogs are disappearing from everywhere in the world except in Hawaii, where the government is trying to make them disappear.
Yet, despite the endless anti-coqui propaganda, people are coming to like the little coqui frog, especially those people who have arrived to Hawaii since the advent of the coqui. To these people, the sound of Hawaii includes the coqui. To these new human immigrants, the coqui is normal, and enjoyable. They understand why the Puerto Ricans love these frogs.
If we are to save the world’s endangered and threatened frogs, and other wildlife that needs rescue from the human-damaged world, we need to change our environmental immigration policy. It doesn’t matter where a species is native, or where it “belongs”. That these species survive is what matters. And this may require finding them a new home.
This is not to suggest that we bring in species willy nilly, without thinking about the impact on local species. We need careful study to know which species can be introduced, and where. But unless we open our borders, and our hearts, to these refugee species, they will die.
We caused their problems. Their fate is in our hands.
ABOUT THE AUTHOR:
Sydney Ross Singer is a medical anthropologist, biologist, and author living on the Big Island of Hawaii. He is an outspoken defender of the Hawaiian coqui frog, has created Hawaii’s first coqui frog sanctuary, and has been featured on Animal Planet, PBS Nature, BBC radio, and Univision. He is co-author of Panic in Paradise: Invasive Species, Hysteria, and the Hawaiian Coqui Frog War (ISCD Press, 2005). His website is www.HawaiianCoqui.org.
Dusk ascends to cover the suburb of Bergvliet under a blanket of darkness. It brings with it the chill of a Wintery August night in Cape Town, South Africa, as a nippy breeze sweeps across the small urban wetland of Die Oog (an Afrikaans word meaning “The Eye”).
This man-made depression was originally dug out some 284 years ago to provide water for livestock on the neighbouring farm of Dreyersdal. In more recent years, however, Die Oog has come to serve a much greater purpose, as a pivotal breeding site for one of Cape Town’s most threatened amphibians, the western leopard toad Ameitophrynus pantherinus.
IUCN listed Amietophrynus pantherinus in Noordhoek - Photo by Maria Wagener of Fishhoek
As little as six years ago it was thought that only several such breeding sites remained in existence, for a species which has suffered massive population declines as a consequence of numerous threats including urban expansion, habitat destruction and population decimation through road kills. Today, conservationists and scientists with the aid of concerned volunteers and the public have listed a total of 52 breeding sites within the Cape Town range of the species. Further eastwards, some 150 kilometres away from southern Cape Town, a largely unprotected population comprising seven breeding sites exists.
Unlike most frogs which remain at water courses throughout the year, toads live in what’s termed ‘foraging areas’ where they lay dormant by day and hunt by night—with an exception for August month and there about when they migrate to and from local aquatic environments to breed. Presently, the majority of these foraging and breeding areas fall under urban suburbia, guaranteeing a window of constant interaction between these toads and the unknowing dangers their human neighbours pose.
Despite current conservation action and volunteer efforts to protect the Cape Town populations, census data from the 2009 breeding season only generated a recorded 1125 live migrants and 258 dead. Great strides have been achieved in recent years through a consistent increase in awareness of the plight of the species and in the recruitment of volunteers. The fate of the species is however uncertain—unless the citizens residing in these areas value their endemic and endangered leopard toad, there will merely remain stories of its once enigmatic nature and quiet existence.
We’re proud to feature guest blogger, Lucy Cooke, The Amphibian Avenger, who tells us about herself, what her mission is, and how we can all help.
I love frogs. I always have. As a small child I became fascinated by the miracle of metamorphosis, catching and studying tadpoles like a true proto frog geek. As an adult studying zoology at Oxford the astonishing diversity of amphibian life seemed to me to most eloquently illustrate the incredible adaptive power of evolution.
When I heard about the global amphibian crisis I was completely horrified and keen to do something about it. I discovered that most of my friends didn’t know that over a third of amphibians are going extinct or about the horrors of the Chytrid fungus. It made me aware of how little press amphibians get compared with birds and mammals so I decided that, as a writer and filmmaker, the best thing I could do would be to spread the word. So for the last few months I have been traveling around Latin America researching stories for a documentary on the crisis and writing a blog about my findings. I’ve been to some amazing places, met some inspirational characters, and discovered some truly awesome frogs. And it’s not over yet.
I started my trip by joining an expedition into the Patagonian wilderness with ZSL [Zoological Society of London] scientists to search for Darwin’s frog – the last of the gastric- or throat-brooding frogs left on the planet and the only species of animal (other than the seahorse) in which the male gets pregnant. After the eggs are fertilised the male gobbles them up and 8 weeks later he burps up baby frogs.
I was lucky enough to see and film a daddy Darwin’s frog carrying several tadpoles in his throat sack. It was one of the freakiest things I have ever seen – a mass of tadpoles wriggling in a frog’s belly – it looked like something out of the movie Alien. It gave me goose bumps to witness something so very special but sadly so very endangered. Darwin’s frog is threatened by habitat destruction and also the rampant spread of the Chytrid fungus. It would be a devastating loss to biodiversity for such an extraordinary animal to disappear off the planet.
But probably the most shocking story I have come across is that of the endangered Lake Titicaca toad, also known as the aquatic scrotum frog after its exceedingly wrinkly appearance. This monster of the deep has become the key ingredient for Peruvian backstreet Viagra. In downtown Lima I filmed juice bars where they put this toad in a blender and then drink it. A fashion which is pushing this unique amphibian to the brink of extinction.
I’ve still got Panama and Costa Rica to go and will be posting from these two countries that have already been forced to brave the first wave of Chytrid. So if you like frogs then follow my blog – I think you’ll enjoy my adventure. Frogs need champions to help raise their profile and the necessary funds to save them. So, please spread the word amongst your non-frog loving friends – it’s written not just for frog geeks and they may well learn something new and start to care about the little green guys nearly as much as me.
To follow Lucy’s adventure on her blog, click here.
I’ve always had a sentimental attachment to cornfields—from the magical cornfield in Field of Dreams to the real cornfield across the road from a house I lived in during college years. My mother was born and raised in Iowa and I’m descended from farmers.
But chemicals, in particular Atrazine, used as herbicides on cornfields might be poisoning frogs (and people), and turning fields of dreams into fields of nightmares. These herbicides run off cornfields into streams and rivers, and leak through the water-treatment process, contaminating groundwater and drinking-water supplies.
Last summer we blogged about the problems of Atrazine. Research by University of California, Berkeley professor Dr. Tyrone Hayes, for example, has shown the effects this chemical—an endrocrine disruptor—has on frogs. It can cause birth defects and reproductive problems, including such bizarre deformities as male frogs with eggs in their testes. This past week, as reported in the Washington Post, new research at the University of Ottawa found that when exposed to Atrazine fewer tadpoles reached froglet stage. Atrazine appears to affect estrogen in humans as well and has been connected with ferility problems, cancer, and birth defects.
Warning in a Cornfield
The EPA, under the Obama administration, has launched a review of the chemical that will continue until fall 2010. It will look closely at Atrazine and other endrocrine disruptors, which might result in tighter restrictions on their use. While this sounds hopeful, Atrazine’s primary manufacturer, Syngenta, has strong ties and influence within the EPA. (Atrazine is banned in Europe, where perhaps industry and government aren’t as closely intertwined as they are in the U.S.).
As the year ends, and before we take a short break for the holidays, we’d like to show you the new poster we’ve created to promote our cause. Proceeds from the sale of the poster will go toward amphibian conservation organizations and toward developing free and inexpensive educational materials for kids.
The poster is a unique collaboration between my partner Susan (who is a graphic designer when she isn’t saving frogs) and illustrator Sherry Neidigh. Sherry approached us after seeing our blog and offered to donate one of her illustrations for our use. We were thrilled to receive this exquisite illustration to promote our cause.
Susan played around with various ideas, but what struck her about this illustration was its dreamy quality. She came up with the text, “A Frog’s Dream….Save Our Home.” I think these words are perfect. That frog looks so content immersed in his pond, surrounded by dragonflies and lily pads.
A bit about Sherry:
Sherry has been drawing animals since she was 2 years old. She attended the Ringling School of Art and Design in Sarasota, Florida, and has worked for Hallmark Cards.
Sherry’s clients include the National Wildlife Federation (Your Big Backyard), Highlights for Children, Sylvan Dell Publishing, and NorthWord Publisher. She works in gouache, watercolor, colored pencils, airbrush, and pen and ink. Her latest book is Count Down to Fall by Fran Hawk, published by Sylvan Dell Publishers. Sherry lives in Simpsonville, South Carolina, outside of Greenville, with her two dogs, Harper and Bisbee. You can learn more about her by visiting her charming website.
Susan and I are so grateful for the use of Sherry’s beautiful illustration. We hope you love the poster as much as we do. Susan also designed a t-shirt with the illustration. Both are available in our store.
