doctor frogs

Doctor Frog to the Rescue!

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Scientists are finding new ways to treat sick people by studying frogs!
This is yet another good reason to be concerned about the fate of our worlds frogs since every day so many frogs are threatened by environmental problems! For example, scientists found a way to make a new drug painkiller from the toxins in a frog's skin. The frog (Epibpedobates tricolor) is found in Ecuador. Poison in its skin protects it from predators. They couldn't use the poison itself for humans because it's too powerful (isn't that amazing?), but researchers took the frog poison (its structure) as a model for this new drug.

Frog-Skin Poison Could Yield New Painkiller (article from 1997) WASHINGTON (Reuters) - A lethal poison in the skin of an Ecuadorean frog could lead to a painkiller that may be stronger than morphine but without morphine's side-effects, researchers reported Friday. The new drug, known as ABT-594, would target the same kinds of severe pain now treated by morphine, including pain associated with some cancers and traumatic injury. The compound, developed by researchers at Abbott Laboratories, has shown promise for pain relief in rats and mice, and is currently being tested on humans in Europe to determine its safety, Dr. Michael Williams of Abbott said in a telephone interview. The compound is similar to substances found in the skin of an Ecuadorean frog, which relieves pain but also causes hypertension, neuromuscular paralysis and seizures. The researchers were able to isolate the pain-relieving properties without including the deadly ones. Williams stressed that research into the new painkiller was at an early stage, with preliminary human trials currently proceeding in Europe and no estimate of when such a drug might get to market. However, he said that in tests on animals, there was no sign of addiction, an important advantage over morphine. Some 30 million to 40 million Americans use morphine to relieve pain, despite serious side effects including respiratory depression, dangerous constipation and addiction, according to the journal Science, which published the research.

Scientists are also studying the mysterious Wood Frog, which can freeze during the winter, to find clues that might help develop new tools for safer human organ transplants.

Frozen Frog May Give Docs Jump on Human Transplants Brian Handwerk for National Geographic News March 1, 2005 The common wood frog displays a rare trait called freeze tolerance. When the mercury falls, the animal becomes, to the eye and touch, a frog- shaped ice cube. The way it does this may eventually be copied to aid human organ transplants. "Two-thirds of their body water, or more, freezes," explained Jack Layne, a biologist at Slippery Rock University of Pennsylvania. "The heart stops, the breathing stops. For all practical purposes you'd assume that it was dead." In reality, the frog's metabolism slows to a crawl, and its body temperature drops to between 21� and 30� Fahrenheit (�6� and �1� Celsius). The amphibian's heart and brain cease to function. Frozen frog experts, such as biochemists Ken and Janet Storey of Carleton University in Ottawa, Canada, believe the animals acquired their ability to withstand a deep freeze about 15,000 years ago, during ice age evolution. During winter hibernation, the common wood frog stops its heart and brain and freezes into what looks and feels like a frog-shaped ice cube. Researchers are studying this uncommon ability to gain insights that may aid the process of human organ transplants. Photograph courtesy Slippery Rock University of Pennsylvania Freeze tolerance allows common wood frogs (Rana sylvatica) to live in harsh climates as far north as the Arctic Circle�the only frogs to do so. But they can also be found as far south in the United States as Georgia. The amphibians cannot survive if their body temperature drops below about 20� Fahrenheit (�6� Celsius). But snow pack and other natural insulators can keep the frogs sufficiently warm during their winter hibernation. A key to their survival is a natural antifreeze that prevents the amphibians' cells from dehydrating excessively during the freezing process. Frozen Brains, Hearts During this process, about two-thirds of the frog's body water freezes. The remainder, including water inside cells, remains liquid. Glucose produced by the amphibian's liver lowers the tissue freezing point (in the same way that ammonia lowers the freezing temperature of a car's windshield wiper fluid, which is mostly water.) The glucose limits ice formation in the body and binds water molecules within the frog's cells. This curbs the damage caused by cell shrinkage, which is common with freezing. "Normally under those freezing conditions, without glucose, the cells would dehydrate completely," said Boris Rubinsky, an engineer at the University of California at Berkeley. In a recent issue of Discover magazine Rubinsky published images of temperature scanning electron micrographs (a sort of heat-based CT scan) of frozen common wood frogs. A cross section of a frog's liver illustrates how water remains in the cells. Rubinsky said he has used other imaging technology to study the frogs. "We've done MRIs of frogs. And without harming the animal, we were able to observe the entire process of [the] freezing of a live animal as it happens in nature," he said. "When it thaws, it thaws from the interior out. � [T]he heart begins to thaw first and then the brain and, only at the end, the limbs." In nature and in the lab, the thawing process takes places of a period of several hours. When complete, the amphibians restart their hearts and hop away unscathed. The process is remarkable but not unique. "There are a number of insect species whose body fluids will freeze quite substantially," said Layne, the Slippery Rock University biologist. He added that about six North American frog species, one European lizard, and a handful of North American turtles also withstand deep-freezing. He suspects the ability may also one day be observed in a number of Asian animal species. Other animals use a variety of mechanisms to deal with cold, from hibernation to migration. So why do frogs freeze? Layne believes that in the case of the wood frogs, freezing is somehow related to reproductive strategy. "Most freeze-tolerant [species] like to breed early in the spring," he said. "They lay eggs in ephemeral ponds that develop from snow melt. [The frogs] have to get into those ponds quickly when they get a good melt, because [the ponds] dry up in summer, and that could result in a lost generation." Frogs in nonfrozen deep hibernation, such as on a pond bottom, take longer to emerge from hibernation to answer the call of the spring mating season. While common wood frogs put their freeze tolerance to good use, many scientists are pondering what use humans might make of the process. Better Organ Transplants? "These frogs and turtles are vertebrate animals and share a lot of things in common with mammals, like organ and tissue structures," explained Jon Costanzo from the Laboratory for Ecophysiological Cryobiology at Miami University in Oxford, Ohio. "It begs the question: If a frog can withstand the freezing of all of its organs at the same time, how can we apply that to humans?" One avenue of particular interest to Rubinsky, the Berkeley engineer, and other researchers is the field of organ transplants. "Fifty thousand people in the United States are waiting for a heart transplant, but only about 3,000 will get one," Rubinsky said. Time is a major constraint. In the case of a human heart transplant, doctors have only five or six hours from the time the donor organ is harvested until it must be implanted in the living recipient. The logistics of quickly moving a matched organ from donor to recipient�who are often separated by considerable distance�make many transplants impossible. But slowing the metabolism of the donated organ via techniques like freezing is a possible solution. "It's the kind of problem in which small improvements could make a big difference," Rubinsky noted. "For instance, having 24 hours instead of 6 could provide a lot more organs to a lot more people." Rubinsky has had some success. In 1999 he and colleagues preserved rat livers in a partially frozen state, then thawed and implanted the organs in "recipient" rats�one of which survived for five days. More recently Rubinsky and colleagues at Sheba Medical Center in Israel have made some progress in freezing rat hearts. But the road ahead will be a difficult one. "When it comes to more complicated structures [researchers] just haven't been making much progress," said Costanzo, the Miami University researcher. He believes science would benefit by trying to more closely mimic nature. "I think, in the past, people used techniques that were very different from what the animals are doing," he said. "The animals are cooling very slowly, and the temperature they remain at is really quite high. Just a few degrees below 0� Celsius [32� Fahrenheit]." The cryoprotectants (additives used to preserve frozen tissue) now routinely used for embryo and sperm preservation were unheard-of a half century or so ago. So who knows where future research may lead? Noting the common wood frog, Layne, the Slippery Rock University biologist, said, "You've got an animal here that experiences total cardiac arrest. Its heart stops. When it comes to things like a [human] stroke, this parallels that in a way. You have a cessation of blood flow and then it starts again. "There's always a medical debate about restoring blood flow after blockage," he said. "These frogs start everything back up, and they don't have the injury. The model might [give] some insight when it comes to conditions like heart attack and stroke." Of course, some eye the frogs and ponder the ultimate human application�life preservation by freezing entire bodies of the deceased. While no door is closed, most scientists agree that success in this arena, if possible, is many years down the road. As Layne noted, "Even nature has not evolved a freeze-tolerant mammal."

Frog Groups

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A group of fish is called a School of Fish.
A group of geese is called a Gaggle of Geese.
A group of sea gulls is called a Flock of Sea gulls.
A bunch of cows and bulls is called a Herd of Cattle.But what do you call a group of frogs? Answer: An ARMY of Frogs! And what do you call a group of toads? Answer: An KNOT of Toads!

It's Raining Frogs!

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Throughout history, there have been tales of raining frogs. These stories, as crazy as they may seem, are actually real events! From Biblical tales of Egyptian storms to British towns suddenly finding themselves covered with frogs falling from the sky, such events are caused when a wind storm passes over a pond or lake teaming with frogs, picking them up and dumping them elsewhere!One recent story, from the Press Democrat news services, was in June of 1997.

"CULIACAN, Mexico- It rained toads in the town of Villa Angel Flores.
A small tornado whirled up a cluster of toads from a local body of water Saturday night and dropped them all the town in the Pacific coast state of Sineloa, the newspaper El Debate reported Tuesday.
Motorists reported the amphibians dropping from the sky around 11 p.m."

But these stories are not uncommon - there was a story as recently as June of 2005 when a Belgrade paper reported a similar incident in Serbia.

Thousands of tiny frogs rained on a town in north-western Serbia, Belgrade daily Blic reported on Tuesday.
Strong winds brought storm clouds over Odzaci, 120km north-west of Belgrade, on Sunday afternoon, but instead of rain, down came the tiny amphibians, witnesses said.
"I saw countless frogs fall from the sky," said Odzaci resident Aleksandar Ciric.
The frogs, different from those usually seen in the area, survived the fall and hopped around in search of water.
Belgrade climatologist Slavisa Ignjatovic described the phenomenon as "not very unusual".
"A wind resembling a tornado can suck in anything light enough from the surface or shallow water. Usually it's just dust, but sometimes also larger objects," Ignjatovic told Blic. - Sapa-DPA

Frogs and Myth

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Lots of different cultures have all kinds of interesting myths pertaining to Frogs.

Frogs and Weather Frogs have been associated with weather in a lot of ancient cultures. I guess this really makes a lot of sense if you consider that they tend to make a lot of noise before rain storms. Some Australian aborigines and Native American groups believed that frogs were the bringers of rain. In India, frogs were believed to personify thunder in the sky. Even the word for "frog" also meant "cloud" in Sanskrit! In China, they see the "TOAD", not the "man" of the moon. The toad is also considered "one of the five poisons of yin." They say that eclipses happen when the "toad in the moon" tries to swallow the moon itself!

Frogs and Luck Sometimes, cultures associated frogs with good and bad fortune. In Japan, frogs are the symbols of Good Luck. One myth I read dealt with the idea that bullfrogs are descended from a great ancestor who could suck all the mosquitoes out of a whole room in a single breath! Some myths are less favoring to frogs and toads. Some folklorists* have claimed that "If the first frog that you see in the spring is sitting on dry ground, it signifies that during the same year you will shed as many tears as the frog would require to swim away in." If, on the other hand, the first frog of spring jumps into the water, you'll experience misfortune all year! However, if the springs' first "hoptoad" come jumping in your direction, you will have many friends; if it jumps away from you, you will lose some. (sounds to me like it's best not to run into the first spring frog!) Some less enlightened people associate frogs, and Toads in particular, as evil incarnations of demons or devils!

Frogs and Warts Some say that you get warts from touching frogs and toads. You get warts from human viruses, not from frogs and toads! Frogs have slimy skin to stay moist when it is dry, and toads have bumpy skin to help camouflage them in their habitat. Some frogs and toads have paratoidal glands which secrete poisons as protection which can cause skin irritations and may be poisonous to some species of animals, but warts have nothing at all to do with the frogs themselves!

The French and the Frogs For some reason, the French have been given the nickname Frogs...There are many different theories about how this came to be... The story I had always heard was that the nickname dates waaay back to sometime around the 18th century, when Paris was surrounded by many swamps...The French nobility that would visit Versailles apparently tended to refer to Parisians as frogs because of the swampy surroundings...and only later did the term get picked up to describe the French in general. Another story I've heard was that American soldiers adopted the nickname for the French during the World War II because they ate frog legs and hid well when camouflaged. I've also heard that a frog used to be on the French Flag, before the Fleurs de Lis was adopted when King Clovis took the throne....

Frogs, Toads and Phobias Batrachophobia- Fear of amphibians, such as frogs, newts, salamanders, etc. Ranidaphobia- Fear of frogs. Bufonophobia- Fear of toads.

Jurassic Frog

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The earliest known frog appeared during the late Jurassic period, about 190 million years ago! Scientists believe that the oldest frogs developed jumping legs to avoid being eaten by dinosaurs.
Specimens on the first known frogs have been found on Navajo Indian reservations in Arizona. Fossils of meat-eating fish and reptiles such as dinosaurs have also been found at the same site.
These fossils show that the skeletal shape and body plan of the frog has remained almost unchanged over the last 190 million years. In addition, frogs had the added advantage of being small enough to be able to hop away to avoid the many predators which habitated its surroundings."

Strange Breeding

Surinam Toad

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The Surinam toad, an aquatic South American toad (family Pipidae), is about 20 cm (8 inches) long. It has small eyes, a flat, squarish body, and a flat head with loose flaps of skin on the face. Its "fingers" have little star-shaped appendages that help them find food.

Photo sent in by J. Powers of Bloomington, Indiana

These bizarre creatures are well known for their weird brooding habits.
They mate in the water, and as the eggs are released the male fertalizes them and presses them to the back of the female.
In the next several hours, the skin grows around the eggs to enclose them in a cyst with a horny lid.
After about 80 days, the eggs develop, and the young emerge out of the back of this toad as a bunch of tiny froglets!

Darwin's Frog

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Another strange frog is the Darwin's frog (Rhinoderma darwinii).
This is a small (1 in./3 cm. in length) frog, species of the (small) family Rhinodermatidae. It got it's name after the fact that Charles Darwin discovered it on his world voyage.
This frog lives in the cool forest streams of South America, mostly in Argentina and Chile.
This frog also has odd brooding habits. The female lays about 30 eggs and then the male guards them for about 2 weeks. Then the male picks up all the survivors and carry around the developing young in their vocal pouch. The tadpoles develope in their baggy chin skin, feeding off their egg yolk. When they are tiny froglets (about half an inch) they hop out and swim away!
Weird!

Gastric Brooding Frog

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Yep...that's a baby frog coming out of a tiny mama frogs' mouth.
This species of frog, called the Gastric Brooding Frog, incubates its' young inside it's tummy...then the frogs come hopping out of the mouth when they develop past the tadpole stage. Scientists were most intrigued by how this species manages to "Turn off" production of hydrochloric acid (the digestive juices) when brooding the froglets.
The Gastric Brooding Frog was found in Australia. Sadly, not long after their discovery they dissapeared and are now believed to be extinct. Also- Yes! That is a thumb you see behind the frog, to show how tiny even the mama is.

dry region frogs

Frogs and Weather

Desert Frogs

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The Catholic frog (Notaden bennetti) is a yellow or greenish Australian myobatrachid which gets to be about 4 cm (1.5 inches) long. It was named for the dark, crosslike pattern on its back, and it lives in dry regions. The way it copes with drought is to live underground, emerging from its burrow after a heavy rain.

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Another desert dweller is the Flat-headed frog (Chiroleptes platycephalus) which is also an Australian myobatrachid. It, too, lives in burrows and is noted for its' ability to store enough water in its body to take on a ball-like shape. *bloat*

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Another dry-region dweller, the Rheoba trachus Silus, swallows its eggs and broods them in its stomach since there aren't any ponds available!!! *YUM!*

Horned Frogs

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Horned Frogs (Ceratophrys), like this Gastrotheca ceratophrys have a projecting flap, or "horn," of skin above each eye.

Albino Frogs

Albino frogs are a fairly common occurance with frogs...
It seems to happen with many different species of frogs and should not be taken to mean that your frog is sick.
Albinism is a condition caused by a recessive gene which causes a person or animal to be born lacking normal pigmentation.
What you end up with is usually a pinkish or whitish or GHOSTLY looking frog, with really weird-looking red eyes. The eyes appear red because the blood vessels of the retina show through the iris, giving it a pink or reddish color.
The eyes of albino animals (and people!) tend to be highly sensitive to light.
For the most part though, folks with albino pets dont have anything to worry about.
These funky colorings can look either really cool or really freaky, depending on the species. It can also make it pretty tricky to identify the species of frog.

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Here is a photo of an African Clawed frog. This great photo that appeared in ABCNews.com's news story "Love Duet in the Pond" (Feb 16, 1998) about love calls of African Clawed frogs.	This photo is of a two-year-old Albino variety of the African Clawed frog Photo sent in by Scott & Vicky Edwards.
Here is a photo of a Pac-Man Frog. This is a picture of pictures of "Sugar", courtesy of Deborah Dana and her family, originally seen on Mike's Herpetocultural Home Page (no longer exists).	Here is the albino version of the same species, the Pac-Man frog. (Photo from the Best Buy Commercial from 1997, featuring this website!)
Photo of a normal colored "Green Frog". This picture courtesy of now defunct website: Animal Diversity Web.	Here is how the green frog looks when it's an albino. Note the yellowish coloring! Photo courtesy of Nova Scotia Frogs

Other examples of albino frogs.

This weird looking guy was found in a garden pond in the UK.
Species: unknown.

how frogs survive

Split in Half!

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Some frogs have developed neat ways to fool predators by stripes that appear to split them in two! The stripe down the scenter confuses predators from above by breaking up the outlines of "frog" shape to look like something different. This way, the frog or toad can blend in easier to it's background.

Poison Glands

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Toads often have puffy looking pockets called paratoid glands located behind the ear that squirt poison at potential predators. So, if you've ever hear a dog "scream" after picking up an American Toad, now you know what happened! Although frogs have poisonous skin glands, these toxins do not usually protect them from predatory mammals, birds, and snakes. Edible anurans have to rely on more than just poison glands which tend to work too late (i.e. after the predator has it in his mouth!)

FLASH! Confuse Your Enemies

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Some species have bright colours on their underparts or legs that flash when the frog moves, presumably confusing enemies.
The enemy gets distracted by the colors, then by the time they remember they were chasing a frog, our froggy friend has leaped away to safety!
This Barred Leaf Frog (Phyllomedusa tomopterna) has little stripes under it's legs that flash when it runs.

frogs enemies

Enemies!

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Frogs have to watch out for all kinds of enemies in the wild. There are a wide variety of frog predators. Animals that eat frogs for snacks include snakes, lizards, birds, and various small animals like hedgehogs. Even under water frogs cant be safe from hungry sharp toothed fish, swimming mammals like water shrews, and even diving birds! As if that wasn't bad enough, frogs even have to watch out for other hungry frogs! Because there are so many bad guys to watch out for, frogs and toads have come up with a large variety of forms of protection. The largest enemy that frogs have isn't something as easily adapted to: Pollution!
Frogs are becoming particularly important as factors in measuring the health of the global environment and in tracking how much ultra-violet light gets into our atmosphere. For some years now, it has been noted that worldwide frog populations have been in the decline. Many species are on the verge of extrinction, while others are thriving well. Only recently has this frog population change been linked to not only a decrease in upper atmospheric ozone layer, but also an increase in low-atmosphere ozone due to pollution. Here's a FACT: Frogs in the environment are a true sign of a well balanced ecosystem!
You can make a difference! Visit Frogland's Save Our Frogs! page to read about our endangered froggy friends

What is a Frog?

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There are around 3,900 species of tailless amphibians, or Anura, also called Salientia, including the frog and toad.

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Amphibians

Frogs are members of the zoological class called Amphibia.
Amphibians are cold-blooded (or poikilothermic) vertebrate animals. They differ from reptiles in that they lack scales and generally return to water to breed.
They are one of three types of Amphibians. Anura, also called Salientia, (frogs and toads), caudate (salamanders and newts) and caecilians (worm-like amphibians).

Herps and Herpetology

Amphibians together with reptiles make up a larger group called Herps. The study of reptiles and amphibians is called Herpetology. Herp comes from the Greek word herpeton, which basically means "creepy crawly things that move about on their bellies."
A herptile is an individual herp. A person who keeps and breeds herps is called a herpetoculturist and the hobby is called herpetoculture.

frog songs

Sing to me baby! ...Ribbit!

Some frogs, like this Squirrel Treefrog (Hyla squirrela) have vocal pouches that vary in size and stretch like balloons. These sacs serve as a resonating chamber, allowing the frogs to SING!
Male frogs vocalize by squeezing their lungs with their nostrils and mouth shut. Air flows over their vocal chords and into their vocal sacs blowing it up like a bubble gum balloon! (Photo courtesy of Chris Harrison)
Other frogs can make noises without such a sac.
(like my Oriental Firebellied Toads - read more about them in the Meet My Pets Page.) For some species of frogs, only the males sing. Other types of frogs appear to have both male and female calls.
Large frogs have DEEP voices, meaning they call at a low frequency.
Small frogs sing in high chirps, meaning they call at a high frequency.
Cold frogs repeat their calls at a slower rate because the muscles controlling the sounds slow down!
Why do frogs sing? Well...it's actually for a variety of reasons!
Sometimes, frogs sing when they are trying to attract a mate. "HEY! Baby!"
Sometimes, frogs sing to mark their territory. "This is MY Lilypad!"
Sometimes, frogs sing becasue they know the weather is going to change. "Rain!!!"
Sometimes, frogs squeek when they are frightened or hurt. "Ouch! Eek!"

What sound does a frog make in YOUR language? Here is a list of some of the different ways people think frogs sound around the world!

Afrikaans: kwaak-kwaak
Arabic (Algeria): gar gar
Catalan: cru�-cru�
Chinese (Mandarin): guo guo
Dutch: kwak kwak
English (USA): ribbit
English (GB): croak
Finnish: kvak kvak
French: coa-coa
German: quaak, quaak
Hebrew: kwa kwa
Hungarian: bre-ke-ke
Italian: cra cra
Japanese: kerokero
Korean: gae-gool-gae-gool
Russian: kva-kva
Spanish (Spain): cru�-cru�
Spanish (Argentina): berp
Spanish (Peru): croac, croac
Swedish: kvack
Thai: ob ob (with high tone)
Turkish: vrak vrak
Ukrainian: kwa-kwa

Here are some REAL froggy calls to listen to:

• Green Tree Frog 
  146KB WAV or 106KB AU
  102KB AU or212KB WAV
• Red Eyed Tree Frog 
  310KB AIFF
  77KB AU 
• White's Tree Frog
  181KB WAV  51KB WAV
• Wood Frog
  153KB WAV 
• Southern Bullfrog 
  83KB AU
• Spring Peeper
  173KB WAV
• Eastern Gray Treefrog
  97KB WAV
• Fowler�s toad
  176KB WAV
• Bullfrog
  115KB WAV
• Northern Leopard Frog
  205KB WAV or 149KB AU
• Southern Leopard Frog 
  143KB WAV or 104KB AU
• Green Frog 
  9KB AU
• Carpenter Frog 
  69KB AU
• Puerto Rican Coqui :
  89KB WAV
• Golden Bell Frog :
  201KB AIFF
• Oriental Firebellied Toad 
  8KB WAV
  11KB WAV
• African Dwarf Frog 
  227KB WAV
  831KB WAV

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More recordings can be found at these sites:

leaping froggies

Leapin' Froggies

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Frogs are one of the best leapers on the planet! Did you know that frogs can launch themselves over 20 times their own length using those big strong legs of theirs? That would be like if you could jump 100 feet! The average flea can jump up to 150 times its own length.
A kangaroo can leap about 4 1/2 times it's length. Elephants can't jump at all! As far as I know, the longest frog jump on record measured 33 feet 5.5 inches. It was made by a frog named Santjie at a frog derby held in South Africa.

Frog Feet

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Feet For Climbing Tree frogs, like this White-lipped Treefrog (Litoria infrafrenata), have sucker-like adhesive disks, or Sticky pads, which aid in climbing, on the tips of the fingers and toes.

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Feet For Swimming Aquatic Frogs like the African Dwarf Frog have webbing between their toes that aid in swimming.
You can test how much this helps by the following little experiment:

1. First, try spreading your fingers and running them through a tub of water.
2. Now, get a plastic sandwich bag and place it over your hand.
3. Spread your fingers and NOW try running it through the water.
   This adds a lot of swimming power!

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Feet For Digging Frogs that burrow into the sand to keep moist in the heat have stubby clawlike fingers that are adapted to digging.
One example is the Plains Spadefoot Toad as seen here.

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Feet For Flying! Some frogs in the Rhacophorus species, such as R. reinwardtii and R. nigropalmus, have parachute-like webbing on their hands and feet which act as an air-brake when they glide from tree to tree or leaf to leaf. These frogs are known as "Flying Frogs."
The image on the right is an old woodcarving of a Javan Flying Frog in descent.Try this little experiment to see how webbing helps:

1. First, take 2 pieces of paper, both the same size.
   
2. Now, spread out one paper flat and drop it. Notice how it takes a while to float to the floor.
   
3. Take the second piece of paper and crumple it into a little ball.
   
4. Drop the crumpled paper from the same height as the first paper. Notice how much faster it falls.
   
   Without the extra webbing, a falling frog would go *SPLAT!*

frogs ears

My, What Big Ears you Have!

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Frogs can hear using big round ears on the sides of their head called a tympanum. Tympanum means drum. The size and distance between the ears depends on the wavelength and frequency of a male frogs call. On some frogs, the ear is very hard to see! Ever wonder how frogs that can get so LOUD manage not to hurt their own ears? Some frogs make so much noise that they can be heard for miles! How do they keep from blowing out their own eardrums?
Well, actually, frogs have special ears that are connected to their lungs. When they hear noises, not only does the eardrum vibrate, but the lung does too! Scientists think that this special pressure system is what keeps frogs from hurting themselves with their noisy calls!

frog teeeth

Do Frogs Have Teeth?

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Actually, yes! But not like in this silly picture!
Most frogs do in fact have teeth of a sort.
They have a ridge of very small cone teeth around the upper edge of the jaw. These are called Maxillary Teeth.
Frogs often also have what are called Vomerine Teeth on the roof of their mouth.
They don't have anything that could be called teeth on their lower jaw, so they usually swallow their food whole. The so-called "teeth" are mainly used to hold the prey and keep it in place till they can get a good grip on it and squash their eyeballs down to swallow their meal.
Toads, however, do NOT have any teeth.

say ahhhhhh

Say "AAAAHHHH!"

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Some frogs have tongues that are long and sticky that can be used to catch bugs. These roll out like an upside-down party horn and snap at the bug! (YUMMY!)
Frogs with long tongues go by the "see it, snap at it" technique of feeding. Toads, on the other hand, like my firebellied toads, have tiny tongues and have to snap at their food using their mouth. They often will stalk their food, much like a cat...creeping up to it and then just as dinner is about to take off, they will *SNAP* and eat their meal! DID YOU KNOW: When a frog swallows a meal, his bulgy eyeballs will close and go down into his head! This is because the eyeballs apply pressure and actually push a frog's meal down his throat! *GULP*
There are about 6 to 14 species of tongueless, aquatic African frogs (family Pipidae) too!

Frogs and Weather

Cold Region Frogs

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Frogs that live in cold regions can't be active year round. When the weather gets cold their bodies cool down and they can't move.
As the temperature drops, frogs burrow a little ways under forest leaves (so they won't freeze to death), and go into hibernation until the weather gets warm again.

Brrrr!!! It's c-o-l-d outside!!

Wood frogs, like this one on the right, are the most widely found frogs above the Arctic Circle. In the winter it can get so cold that you would probably rather be at home with a cup of hot cocoa! These frogs have found some very interesting ways to adapt to this cold weather.
When the temperatures start to drop, Wood Frogs will go buries itself and then shuts itself down. As the temperatures get harsher, the frogs create glucose in their liver by breaking down glycogen using enzymes. This glucose goes out into their body organs and is distributed throughout the bloodstream.
The Wood Frogs are one of serveral species that have the amazing ability to completely freeze solid! (Peepers can do the same...except that in their case they have lots of glycerol, not glucose, in their system)
Since there's so much glucose in the Wood Frog's system, their organs don't get damaged because the sugar in their blood acts as anti-freeze. They can stay completely frozen like that for 2 weeks or more. They stay frozen for as long as the temperature of the ground is below freezing. They have no choice. They are the exact temperature of the environment they are in. When they thaw out, it's like an icecube coming to life!
The first thing that happens when they thaw is the heart starts beating again. Then they start gulping air and shaking out their limbs. Finally, the when the frog is fully recovered, he can hop away!
Why is this important? Just think what it could mean for people if we could develope drugs that do the same thing for humans! "Needs a heart transplant? No hearts available?? Okay, give him 500cc's of froggie coolaid and throw him in the cooler!" And you'd never guess what the first thing these frogs want to do when they thaw out is!
No, not breakfast - they go find the nearest breeding ponds!! In fact, these guys are known as very explosive breeders.
The term "explosive" refers to the duration of their breeding activity. The woodfrog breeds only for a few short nights, sometimes only one night! This is contrast to the breeding duration of say the Green Frog (R. Clamitans) whose breeding season is 2-3 months!
(I guess that would explain why they'd be in such a hurry to get to that breeding pond)
Nor are these guys particluarly picky! ANY pool of water will do (Even if it's not completely thawed water yet or if its just a puddle!)

how frogs live

Many frogs are so poisonous that they can afford to flaunt their colors!
 It is very bright because most animals know that eating a colored frog like this would be deadly!

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Some frogs and toads rely on a combination of camouflage and poisons.
For example, the Oriental Firebellied Toads, like the one on the left, are well camouflaged when seen from above by having black and greenish spots all over their backs. They look just like the types of mosses frequently found in the streams where they are usually found. But when startled on land, they often will raise the head, exposing their bright orange bellies! When the toads are "freaked out" they secrete a poisonous film that can make you sick. The color on their tummies signifies poison!The frog on the left is a Red poison arrow frog

The Chilean Four-eyed frog has a pair of eyespot marks on its rear end. They are really big poisonous glands with spots on them, but it looks like eyes when you look at them from behind. The spots usually are covered by the thighs when the frog is sitting, but when it feels any threat, it will expose the "fake eye spots" and cause them to swell up a bit, which (hopefully for the frog) will fool the predator into thinking that he is bigger and meaner than he really is!

life span of a frog

How Long Do Frogs Live?

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Amazingly, this is the hardest question I've been asked about frogs! It turns out that very little is known at all about the natural lifespan of frogs. Partially, this is because it's pretty hard to track a frog all its life! (I guess they havent figured out a good way to put little tiny collars around their necks!) However,some records show that in captivity, many species of frogs and toads can live for surprisingly long times. They seem generally average somewhere between 4 and 15 years!
Recently I ran across a page where people were posting data about how long their species of frogs had lived in captivity. The longest lifespan entered was a European Common Toad (Bufo bufo ssp.) at 40 years!!!!! Other species which live to ripe old ages include:

• Giant Toad (Bufo marinus): ranging between 7 and 24 years
  
• Green And Black Poison Dart Frog (Dendrobates auratus): ranging between 7 and 17 years
  
• Oriental Fire-bellied Toad (Bombina orientalis): ranging between 11 and 14 years
  
• Ornate Horned Frog (Ceratophrys ornata) ranging from 5 to 12 years

frogs skin

frogs skin

Frogs have very special skin! They don't just wear it, they drink and breathe through it.
Frogs don't usually swallow water like we do. Instead they absorb most of the moisture they need through their skin. 

Not only that, but frogs also rely on getting extra oxygen (in addition to what they get from their lungs) from the water by absorbing it through their skin. Because frogs get oxygen through their skin when it's moist, they need to take care of their skin or they might suffocate. Sometimes you'll find frogs that are slimy. This is because the frog skin secretes a mucus that helps keep it moist. Even with the slimy skin, these frogs need to stay near water. Toads on the other hand have tougher skin that doesn't dry out as fast, so they can live farther from water than most frogs.
In addition to jumping in water, frogs and toads can get moisture from dew, or they can burrow underground into moist soil.
Frogs shed their skin regularly to keep it healthy. Some frogs shed their skin weekly, others as often as every day! This looks pretty yucky...they start to twist and turn and act like they have the hiccups. They do this to stretch themselves out of their old skin! Finally, the frog pulls the skin off over it's head, like a sweater, and then (this is gross) the frog EATS IT!!!! (EEEEEWWW!)     

eyes of the frog

I Only Have Eyes For You!

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Frogs have variable kinds of eye types. The colored part of the eye is called the iris (EYE-riss). They can be brown, green, silver, red, bronze, and even gold.
The pupils come in all kinds of shapes too! (2) Round pupils: Some frogs have round pupils just like you and me. Newts and Salamanders also have round pupils.

(2) Vertical pupils: Vertical pupils that look like a cats eye are really good for night vision and respond quickly to changes in light.

(3) Horizontal-Shaped pupils: These are the more common pupil, good for normal day-vision.

(4) Heart-Shaped pupils: I'm not sure if it serves any purpose, but it sure looks neat! Oriental fire-bellied Toads have this type of pupil.

Some frogs have Triangular pupils, and some even have Star-Shaped pupils!

life cycle of frogs

Life Cycle of a Frog

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True Love? When Frogs mate, the male frog tends to clasp the female underneath in an embrace called amplexus. He literally climbs on her back, reaches his arms around her "waist", either just in front of the hind legs, just behind the front legs, or even around the head. Amplexus can last several days! Usually, it occurs in the water, though some species, like the bufos on the right mate on land or even in trees!(photo courtesy of Emile Vandecasteele)
While in some cases, complicated courting behavior occurs before mating, many species of frogs are known for attempting to mate with anything that moves which isn't small enough to eat!

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Spawn (egg-mass) While in the amplexus position, the male frog fertilizes the eggs as they get are laid. Frogs tend to lay eggs single eggs in masses, whereas toads usually lay eggs in long chains.
Some frogs leave after this point, but others stick around to watch over the little ones. Some have very unusual ways of caring for their young. You'll learn about some of those later in this tour!.

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Egg Frogs and Toads tend to lay many many eggs because there are many hazards between fertalization and full grown frogness! Those eggs that die tend to turn white or opaque. The lucky ones that actually manage to hatch still start out on a journey of many perils.
Life starts right as the central yolk splits in two. It then divides into four, then eight, etc.- until it looks a bit like a rasberry inside a jello cup. Soon, the embryo starts to look more and more like a tadpole, getting longer and moving about in it's egg.
Usually, about 6-21 days (average!) after being fertilized, the egg will hatch. Most eggs are found in calm or static waters, to prevent getting too rumbled about in infancy!
Some frogs, like the Coast foam-nest treefrog, actually mate in treebranches overlooking static bonds and streams. Their egg masses form large cocoon-like foamy masses. The foam sometimes cakes dry in the sun, protecting the inside moisture. When the rain comes along, after developement of 7 to 9 days, the foam drips down, dropping tiny tadpoles into the river or pond below.

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Tadpole Shortly after hatching, the tadpole still feeds on the remaining yolk, which is actually in its gut! The tadpole at this point consists of poorly developed gills, a mouth, and a tail. It's really fragile at this point. They usually will stick themselves to floating weeds or grasses in the water using little sticky organs between its' mouth and belly area. Then, 7 to 10 days after the tadpole has hatched, it will begin to swim around and feed on algae.
After about 4 weeks, the gills start getting grown over by skin, until they eventually disappear. The tadpoles get teeny tiny teeth which help them grate food turning it into soupy oxygenated particles. They have long coiled guts that help them digest as much nutrients from their meadger diets as possible.
By the fourth week, tadpoles can actually be fairly social creatures. Some even interact and school like fish!

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Tadpole with legs After about 6 to 9 weeks, little tiny legs start to sprout. The head becomes more distinct and the body elongates. By now the diet may grow to include larger items like dead insects and even plants.
The arms will begin to bulge where they will eventually pop out, elbow first.
After about 9 weeks, the tadpole looks more like a teeny frog with a really long tail. It is now well on it's way to being almost fullgrown!

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Young Frog, or Froglet By 12 weeks, the tadpole has only a teeny tail stub and looks like a miniature version of the adult frog. Soon, it will leave the water, only to return again to laymore eggs and start the process all over again!

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Frog By between 12 to 16 weeks, depending on water and food supply, the frog has completed the full growth cycle. Some frogs that live in higher altitudes or in colder places might take a whole winter to go through the tadpole stage...others may have unique development stages that vary from your "traditional" tadpole-in-the-water type life cycle: some of these are described later in this tour.
Now these frogs will start the whole process again...finding mates and creating new froggies.

Frogs and Toads

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One of the most common questions is, "What is the difference between Frogs and Toads?" Most are surprised to hear that all Toads actually are Frogs!



Frogs
Generally speaking, though, when we think of frogs, we generally picture what are called "True Frogs"....
members of the family Ranidae, containing more than 400 species.
These frogs have the characteristics of:

• two bulging eyes
• strong, long, webbed hind feet that are adapted for leaping and swimming
• smooth or slimy skin (generally, frogs tend to like moister environments)
• Frogs tend to lay eggs in clusters.

Frogs from this family can be found on every continent except Antarctica. They are referred to as the "true frogs" because of their generalized body form and life history: the so-called generic frog.
Members of this family include the bullfrog, common frog, green frog, leopard frog, marsh frog, pickerel frog, and wood frog.



Toads

The term toads tends to refer to "True Toads"....
members of the family Bufonidae, containing more than 300 species.
These types of frogs have are characterized by:

• stubby bodies with short hind legs (for walking instead of hopping)
• warty and dry skin (usually preferring dryer climates)
• paratoid (or poison) glands behind the eyes
• The chest cartilage of toads is different also.
• Toads tend to lay eggs in long chains. (There are some toads (genera Nectophrynoides), however, that are the only types of anurans to bear live young!)

True Toads can be found worldwide except in Australasia, polar regions, Madagascar, and Polynesia, though Bufo marinus has been artificially introduced into Australia and some South Pacific islands.
Besides Bufo, the family includes 25 genera, all of which, like the frogs, are anura!