Frogs & amphibians
Archived posts from this Category
Archived posts from this Category
Posted by Celia Clark on Nov 25, 2009
Earlier this year, PETA partnered with pathologist Dr. Nancy Harrison to produce a short video with highlights of The Digital Frog 2.5. We first met Nancy a few years ago when she was presenting her research on dissection alternatives to science teachers in San Diego.
We could not help wondering why a practicing pathologist, who dissects human tissue for a living, would be taking the time to research dissection alternatives. This is what she says on the Dissection Alternatives website hosted by the Physicians Committee for Responsible Medicine website:
“As a pathologist, I perform careful dissections every day‚ on human tissues, not on animals. It’s my job to know the relationship between anatomy and physiology, between health and disease.
But it wasn’t the frog or cat dissections we performed in public school that inspired me to study science. It was my excellent science teachers! The energy they poured into our classrooms, the academic heights they challenged us to reach, and their own bright intellects drew me into this field.
Decades later, I’ve come to regret those dissections and have since studied computerized alternatives that are extremely comprehensive. As a doctor who performs autopsies, I can assure students that computer images of well-preserved tissues look more like the “real thing” than the squishy gray organs of a formalin-fixed specimen. Simulated dissection is very realistic, the accompanying text is elegant, and the graphics are superb. Computerized alternatives are rapidly replacing animals in medical and veterinary colleges across the country. And the same is true at earlier levels of training. That means that younger students can easily learn biology by taking advantage of state-of-the-art methods that do not involve dissecting at all. My heartfelt gratitude goes out to science teachers everywhere who are creating a passion for humane scientific study. Tomorrow’s great physicians and researchers depend on it.”
We were not involved in the production of this video, but are thrilled with all that Nancy has to say about our program, The Digital Frog 2.5 and that she is one of our biggest supporters and proponents. And Nancy will not even allow us to buy her a cup of coffee!
We find it interesting that The Digital Frog 2.5 has also been voted the best dissection alternative by eSchool News readers. However, we created the program to teach anatomy and physiology, not dissection skills. We included the dissection module to bridge the gap between the traditional way of teaching anatomy and physiology and the 21st century way – better, kinder and much more cost effective way.
And one thing that Nancy does not mention is that schools can save huge amounts of money by teaching anatomy and physiology with The Digital Frog instead of with wet labs and textbooks. We have just returned from a science teachers conference in Texas. One middle school principal, who purchased a Building Site License for The Digital Frog 2.5 last year, stopped by our booth to say that he has already saved $1,200! You’ll be amazed at the cost savings, especially for large schools.
Posted by Celia Clark on Jul 01, 2009
A few days ago, Jim, our webmaster, sent me a link to an article from the BBC about recent research on the “mystery of the missing frog legs“. For years there has been a common belief that various environmental factors play roles in the widespread and increasingly common deformities, such as missing legs, being found in frog populations.
We believed this to be such a fundamental topic in teaching about frog ecology that we even dedicated an entire screen in The Digital Frog 2.5‘s ecology section to the issue. On the page about environmental concerns, we wrote:
Many scientists consider frogs important bio-indicators. Frogs have permeable skin and live both on land and in water. As a result, environmental problems quickly affect frogs.
Recently, frog populations have declined or disappeared around the world, and deformities and mutations are becoming common. People have found adult frogs with misshapen bodies, extra legs, missing or abnormal organs, and even eyes growing inside mouths!
Frog deformities, mutations and declining populations are not likely to result from any single cause; it is much more probable that many factors affect our amphibian friends. Scientists have identified holes in the ozone layer, chemicals, pollution, habitat loss and frog harvesting as possible causes.
Laboratory tests with ultraviolet light have produced frogs with leg deformities. Scientists speculate that holes in the ozone layer may allow enough ultraviolet light through to affect frogs in the wild.
Amphibian skin absorbs chemicals from both land and water. Tests show that some chemicals, pesticides, and industrial pollutants cause mutations, abnormal growth, or fatal deformities in frogs.
Industrial and agricultural by-products can harm local frogs. Acid rain and runoff rain can carry these chemicals to places far removed from human habitation.
Habitat loss is probably the biggest single factor in declining frog populations. Wetlands are frequently drained, filled in, or otherwise destroyed, depriving frogs of places to live. Commercial harvesting is another pressure.¬† Worldwide, hundreds of thousands of frogs are captured each year and used in laboratories, schools, and restaurants; this causes serious declines in certain species.
We used four frogs in the original Digital Frog, and none had deformities. This version required five frogs, and we discovered internal deformities in three of them.
New research suggests that there are two more natural causes contributing to frog deformities:
1. The fungal condition chytridiomycosis which has brought rapid extinctions to some amphibians.
2. The deformed frogs are actually victims of the predatory habits of dragonfly nymphs, which eat the developing hind limbs of tadpoles! Remarkably many tadpoles seem to survive the ordeal, resulting into as much as 10% of frog populations missing limbs. You can read more on the BBC’s Earth News page (and even watch the video evidence of one hapless tadpole being made a victim by a dragonfly nymph).
In other frog research news, yet another recent study suggests that up to one billion frogs are taken from the wild for human consumption each year. Not to mention the millions of frogs that are cut up every year in schools around the world. No wonder frogs are used as the poster children of the natural world!
Posted by Jim Bridges on Oct 30, 2008
Do you know of an outstanding middle or high school student or teacher who has made strides to replace dissection with humane, non-animal teaching methods or who has implemented or expanded a dissection choice policy?
Do you think they (and their science department) might appreciate $1000 each for their efforts?
The winning student and educator will each receive $2,000, which includes $1,000 for each recipient and $1,000 for their schools.
Any high school or middle school teacher or student who has made significant moves to replace dissection in primary or secondary schools with humane, non-animal alternatives is eligible to receive an award. Please also make biology teachers at your school aware of this opportunity.
PCRM is a nonprofit organization with a membership of 6,000 physicians and more than 100,000 other medical professionals, scientists, educators, and laypersons. PCRM conducts clinical research, promotes preventive medicine, and seeks higher ethical and scientific standards in research and education. To that end, we urge educators to eliminate harmful animal use, including dissection, in favor of validated non-animal learning methods.
A growing number of students and educators realize that non-animal learning methods teach concepts of anatomy and biology just as well or better than traditional dissection. These non-animal methods also teach students to value and respect all life forms and can save schools money.
You can submit your nomination online. (They even say that self-nominations by students and teachers are not only welcomed, but encouraged.) Nomination deadline is December 1, 2008.
Posted by Tracie Treahy on Apr 22, 2008
I am glad the frogs don’t have to depend on me alone for their survival‚ÄîI never managed to get my frog safely across the road.
Frogster is a new game for children on the Vancouver Aquarium website. The idea is to lead your frog safely across the road avoiding various natural and man made threats.
The plight of the frogs and amphibians is serious and this is another way to deliver that message to children. The game will remind all of us “slightly” older folks of the original video games for Commodore 64 and Atari. The perils to avoid in Frogster are air pollution, water pollution, loss of habitat, climate change, human interference and Chytrid fungus. Frogs in the natural world are having a hard time avoiding these threats and the poor frogs in my game were no better off. The hope of this game’s introduction on the website is to draw more attention to the overwhelming decline in the amphibian population due to habitat loss and the Chytrid fungus as well as to stimulate fund raising efforts for the Year of the Frog.
(To help these efforts, Digital Frog International will be donating 5% of The Digital Frog 2.5 sales to Amphibian Ark this year.)
Posted by Tracie Treahy on Apr 14, 2008
Sitting anxiously awaiting the signs of spring, I was listening to a radio program asking listeners to call in with their favorite signs of spring. It got me thinking about mine. Thinking about it I realized I have favorites for different senses. I love to see the first buds of green poking their way out of my garden or the new leaf buds on the trees; of course the early flowers are great too.
Spring has a smell to me, rain and new earth, with last year’s vegetation composting on the ground it adds to that rich earthy smell. Sometimes the smell can be too much, like when the local farmers spread the manure on the new spring fields!
My favorite sound is definitely the Spring Peepers. On my evening walks with the dogs I pass by a couple of wet areas and the chorus of frog chirps is unbelievable. The Peepers are the first frogs out in the spring and can be found in most of eastern North America. These amazing little guys are only .75-1.25 inches long yet they sing a mighty song. We have had great fun learning different frog calls with The Digital Frog 2.5 program. In the ecology section many frog and toad species are investigated and you can listen to and learn their calls.
To hear the distinctive call of the spring peepers, click on the player below.
I also enjoy the earthy flavor of fiddle heads found on our walks (though we usually find them after they unfurl). Now that spring is here I can feel the sun and breeze on my face as I no longer need everything covered up!
What are your favorite Spring experiences?
Add your Spring comments for a chance to win a copy of ScienceMatrix: Cell Structure and Function.
Posted by Celia Clark on Apr 13, 2008
Being dubbed the “frog lady” by all and sundry results in friends and family alerting me to all things froggy.
So I regularly receive emails about froggy topics such as the 70-million-year-old fossil of a giant frog unearthed in Madagascar, the killer disease chytridiomycosis (a fungal disease that has been blamed for the extinction of one-third of the 120 frog species lost since 1980) and even an article about an Iranian woman giving birth to a frog (and the date was not April 1!).
Yesterday, I received several emails about the recent discovery of a lungless frog in Indonesia. One thing that bothered me about some of the articles was the implication that it is unusual for frogs to breathe through the skin as it’s know that frogs breathe in three different ways: though their mouths, lungs and skin. So I consulted the respiratory system module in the Anatomy and Physiology section of The Digital Frog 2.5. This is a small part of what it has to say:
Frogs have three different methods of respiration, or gas exchange:
- cutaneous respiration takes place across the skin,
- buccopharyngeal respiration occurs in the mouth,
- pulmonary respiration uses the nares, mouth, and lung
On land, most oxygen absorption occurs in the lungs. In water, most gas exchange takes place across the skin, but even the most aquatic frogs must come up to the surface to breathe. Most carbon dioxide is released across the skin. While hibernating, frogs do not use their lungs and depend on cutaneous respiration.
It seems frogs are much more versatile than us humans. But then, of course, we are not amphibians.
If you have any quirky frog stories to share, add a comment for your chance to win free software.
Posted by Celia Clark on Mar 04, 2008
I may be known as the frog lady these days, but there was a time when I could not tell a frog call from a bird call. That all changed when I became involved in Digital Frog International. The biodiversity section of The Digital Frog 2.5 features frogs and toads of North and South America, together with sound recordings of their calls.
Way back in 1995, we gave the first version of The Digital Frog to our vet to review. She reported back that her two year old son spent hours and hours clicking on the frogs and listening to their calls.
A few years ago we donated software to the Toronto Zoo and I spent a day in their conservation area helping visitors navigate our software. The frog calls were extremely popular.
I have also used this section to help children identify the spring peepers, northern leopard frogs, green frogs, wood frogs and tree frogs that can be found on our country property. Last summer my grandchildren were fascinated as they watched a grey tree frog, quickly nicknamed “Norman”, change from grey to green as he emerged from his hiding place. From then on, whenever they heard a tree frog call, they all rushed out looking for Norman.
Of course, I still secretly believe that the herpetologist who provided the recordings we used in the program was playing a joke on us ‚Äîthe bullfrog sounds just like a cow!
To learn more about the frog calls and other information on the frogs and toads of North and South America available in The Digital Frog 2.5, read more about the program’s ecology section. Or preview it for yourself with a free demo of The Digital Frog 2.5.
Posted by Jim Bridges on Mar 01, 2008
As part of the Year of the Frog, the Vancouver Aquarium has produced “Bullfrog Ballet”, a two-minute, high-speed video showing bullfrogs feeding on insects in slow motion, giving them a grace you might not normally associate with large (and seemingly ungainly) bullfrogs.
From the Vancouver Aquarium’s description:
Bullfrogs (Rana catesbeiana) are native to eastern North America, from Canada as far south as Florida, but they’re invading British Columbia, where the Vancouver Aquarium is located. They were introduced here in the early 1900s by people wanting to farm them for their legs.
As you can see, they’ll eat just about anything that will fit into their mouth. They can easily tip the delicate balance of nature in places where they are not naturally found.
Ironically this widely introduced species is disappearing in Ontario, Canada — part of its natural range.
The video is part of a wider exhibit running at the aquarium, “Frogs Forever?”, to raise awareness of the dangers facing the world’s frog populations and what we can do to help.
Posted by Tracie Treahy on Feb 25, 2008
I have always had an interest in the natural world and its inhabitants, but have certainly grown fonder of frogs since coming to work at Digital Frog International.
This year, 2008 has been dedicated as the Year of The Frog not because of the Chinese Zodiac, but because of the dire situation for frogs and amphibians around the world.
After surviving for over 360 million years, frogs and other amphibians are dying the world over. We could lose as much as 1/3 to 1/2 of the known 6,000 species in our lifetime. Loss of habitat is a big threat, but Chytrid Fungi is quickly becoming the greatest threat to frogs and amphibians. A new strain of the fungi was discovered in 1999, Batrachochytrium dendrobatidis and it is believed this is responsible for the widespread demise or many amphibian species.
I have four children and that is not the legacy I want to leave them. They deserve a healthy world with diverse species in it.
We need to take responsibility for the destruction of habitat; frogs are like the canaries in the coal mine , they are indicators of environmental health. The destruction of this species will be a forerunner for many more to follow.
We can help through agencies like Amphibian Ark who are trying to improve public awareness of the frog‚Äôs and amphibian‚Äôs dire situation. The global conservation plan is to keep species that will go extinct in captivity until the time comes that they can be secured again in the wild.
I do feel that we are doing something at Digital Frog by offering an alternative to real frog dissection, by doing virtual dissection we are saving frogs.
I am spreading the word among my friends and family about the frog‚Äôs troubles and hope you can do the same. We all know how fast things can spread when I tell two friends, they tell two friends etc.
Locally we can help to clean up and maintain healthy ponds and wetlands for our North American frogs.
I have taught my children from a young age that looking after the whole environment, not just our small part is an important responsibility, and one that we all need to take seriously. We have enjoyed some great family times over the years helping with clean-ups in our community. I am sure your community does something similar and if not maybe that is something you and your family would like to take on in this all important Year of the Frog