Lizards, which people often confuse with salamanders, typically hold their bodies higher off the ground. The arboreal salamanders use these same movements to climb trees. Some frogs, especially those frogs with short hind legs, also get around mainly by walking. The Roraima bush toad is an example. This little toad walks slowly over the rocks where it lives. If it needs to escape quickly, it tucks in its legs so it forms a little ball and rolls off the face of the stone. Hopping The frogs and toads are the hoppers and leapers among the amphibians. They have two especially long ankle bones in their hind legs, as well as a long rod of bone in the hip where the jumping muscles attach.
They also have a strong but springy chest that can catch the frog safely as it lands on its front feet. Not all frogs and toads hop, but most do. Some, like most of the frogs in the family called true toads, have short hind legs and can only hop a short distance. Others, like most of those in the family called true frogs, have long and powerful hind legs that help them leap several times their body length. Some people even hold frog-leaping contests and bet on the frog they think will jump the farthest. Swimming Adult frogs swim much as they leap, shoving off with both hind feet at the same time.
The frogs that are the best swim- mers typically have large hind feet with webbing stretched be- tween the toes and to the toe tips or close to the tips. Tadpoles do not have any legs until they start to turn into froglets, but they can swim by swishing their tails. Salamander larvae and the aquatic adult salamanders may or may not have tiny legs, but they all use their tails to swim.
Burrowing Caecilians burrow head-first into the moist soil where they live. Frogs may burrow head-first or hind feet-first. The spade- foot toads are one of the groups of frogs that dig backwards into the soil, scraping through the soil with their back feet while wriggling backward. This buries the frog deeper and deeper into. The sandhill frog that lives in Australia is one of the frogs that digs head-first by paddling its front feet and making it look as if it is swimming down into the sand. Gliding A few of the frog species, including the flying frogs in the family known as the Asian treefrogs, can soar through the air.
They do not flap their front legs or have feathers like a bird, but they do have long toes that are separated by webbing that reaches the toe tips.
When they widen their toes, the feet look almost like fans. These treefrogs can leap off a tree branch high above the ground and glide safely to earth by using their fan- shaped feet to keep from falling too fast. They are also able to steer by moving their feet one way or the other. Meat eaters Many amphibians eat meat or are carnivorous kar-NIH- vor-us.
For most of them, their meals are insects, spiders, and other invertebrates in-VER-teh-brehts , which are animals without backbones.
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Often, larger species will eat larger prey. Most caecilians eat earthworms, termites, and other inverte- brates that live underground. Mexican caecilians, which may grow to Most salamanders eat earthworms or small arthropods AR- throe-pawds , which are insects and other invertebrates with jointed legs. Adult frogs also usually eat invertebrates, but if they are able to capture a larger prey and swallow it, many will. The bullfrog, which is common in much of North America, will eat anything and nearly everything from other frogs to small snakes, rodents, and even small birds.
Many amphibians hunt by ambush, which means that they stay very still and wait for a prey animal to happen by. Some amphibians hunt by foraging FOR-ij-ing , when they crawl, hop, or swim about looking for something to eat. Many am- phibians simply snap their mouths around the prey and swal- low it.
Some flick their tongues out to nab it and then reel their tongues and the prey back into their mouths. Many salaman- ders have especially long tongues. Many have beaklike mouths that scrape algae AL-jee and other scum from rocks and under- Amphibian behavioral and water plants. Some, like the tadpoles of spadefoot toads, will physiological defense eat invertebrates in addition to plants.
Marine toad Bufo marinus inflates its lungs and enlarges; b. Birds, able to detach ; c. Even insects, like diving beetles, d. Echinotriton andersoni can kill a tadpole. For most amphibians, the best defense against protrudes its ribs; e. Bombina their predators is to remain still and let their camouflage colors frog displays unken reflex. Illustration by Jacqueline help them stay out of sight. Frogs, in particular, are often the Mahannah. Reproduced by same color as their surroundings. Some, like the horned frogs, permission.
Other amphibians are very brightly colored. The juvenile east- ern newt, for example, is bright orange red. This newt also is very poisonous, and its bright colors advertise to predators that they are dangerous to eat. When numerous amphibians are attacked, they will stiffen their bodies, arch their backs, and hold out their feet.
This position is called the unken OONK-en reflex. The fire-bellied frogs use this position, which shows off their bright red, yel- low, or orange undersides and the similarly colored bottoms of their feet. The colors may remind predators that these frogs have a bad-tasting poison in their skin and convince them to leave the frogs alone.
Although it is not very common, some amphibians will fight back if attacked. Adult African bullfrogs will snap at large preda- tors, even lions or people, who come too close to the frogs or their young. Among salamanders, the large hellbenders can give a painful bite. The females produce the eggs, and the males make a fluid that contains microscopic cells called sperm.
An egg will only develop into a baby amphibian if it mixes with sperm. In almost all frogs, the male climbs onto the back of the female, and as she lays her eggs, he releases his fluid so that the eggs are fertilized outside. Salamanders fall in between these two types of fertilization. In most salamanders, the male puts drops of his fluid along the ground, and the female follows along behind to scoop up the droplets and put them inside her body with the eggs. All amphibians either lay their eggs in the water or in a moist place where the eggs will not dry out.
Most amphibian eggs hatch into tadpoles or larvae before becoming miniature versions of the adults. Often, these eggs, tadpoles, and larvae develop in the water. A number of species have young that never enter the water. In many of these amphibians,. Reproduced by permission.
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Some may even enter states of deep sleep for parts of the year when the weather is too cold or too dry. Day and night Most amphibians are nocturnal nahk-TER-nuhl , which means they are active at night. Nocturnal animals hide some- place during the day. Sirens, which are the two-legged sala- manders, spend their days buried in mud. Many frogs likewise stay out of sight during the day, sometimes hidden under- ground, in a rock crevice, or in some other hiding place, and come out at night to look for food or to mate.
By being active at night instead of the daytime, these amphibians can avoid many predators that rely on their eyesight to find prey. Nights are also usually more humid than days, so the amphibians can keep their skin moist better if they are only active at night. In many cases, these species have especially poisonous or bad-tasting skin that protects them from daytime predators. Many of the poison frogs of South America, for example, are diurnal. On rainy days, some of the nocturnal amphibians will come out of hiding and wander about. With the wet weather, they can keep their skin moist. During the seasons Many species of amphibians are active only during some times of year.
Those that live in climates with a cold winter often spend the winter underground or in another sheltered spot and enter a state of deep sleep, called hibernation high-bur-NAY-shun. The bodies of some species, like the wood frog in the family of true frogs, actually freeze in the winter, but they are able to thaw out the following spring and continue living.
Many other cold- climate species become active again when the spring arrives. Salamanders in the northern United States, for instance, start to move about on land even before the snow melts. Frequently, in these species, the spring also is the time for mating. Besides the cold-weather species, some other amphibians en- ter a state of deep sleep when the weather becomes too dry. For species that live in deserts or dry grasslands, such as the water-holding frog of Australia, many burrow down into the ground and wait there until the next rainy season arrives.
A pe- riod of deep sleep during a dry period is known as estivation es-tih-VAY-shun. In these species, the rainy season marks the beginning of the mating period. Amphibians that live in warm and wet tropical areas usually are active all year long, but they often mate only on rainy days.
Nearly everyone has seen a frog or heard one calling during its mating season. Because neither salamanders nor caecilians have mating calls, and both usually stay out of sight during the day, many people have seen few, if any, of these two types of ani- mals. Frogs are also much more common pets than salaman- ders or caecilians. In addition, many people eat frogs and some even eat tadpoles, but few people eat caecilians or salamanders. Scientists are interested in amphibians for many reasons.
In some species, their skin poisons or other chemical com-. Scientists also use amphibians to learn how their bodies work and therefore learn more about how human bodies func- tion. Perhaps most importantly, ecologists see amphibians as living alert systems. After this discovery, many other Through the World Conservation Union, people began reporting other deformed which goes by the initials IUCN, scientists frogs.
Scientists immediately started keep track of how well amphibians, along tests and experiments to learn why the with other organisms, are surviving on Earth. This category means that scientists do not have enough information to make a judgment about the threat of extinction. The number of amphibians listed as Data Deficient is quite large: 1, species of frogs, 62 species of salamanders, and caecilians.
Amphibians in danger The IUCN lists species of frogs and forty-seven species of salamanders as Critically Endangered and facing an ex- tremely high risk of extinction in the wild; frog species, salamanders, and one caecilian are Endangered and facing a very high risk of extinction in the wild; frogs, 86 sala- mander species, and three caecilians are Vulnerable and facing a high risk of extinction in the wild; and frogs and fifty- nine salamanders are Near Threatened and at risk of becoming threatened with extinction in the future.
Many of these species are at risk because the places where they live or breed are disappearing or changing, perhaps as. Amphibian morphological people cut down trees for lumber or otherwise clear the land defense mechanisms; a. Some of the other darwinii uses camouflage and problems for amphibians come from air and water pollution, cryptic structure; b. Pseudotriton infection with a fungus that is killing amphibians around the ruber and Notophthalmus viridescens display mimicry; world, and global warming.
Global warming changes weather c. Bufo americanus has poison patterns, sometimes causing especially dry conditions in some parotid glands; d. Poison dart places. Since frogs need to keep their skin moist, especially dry frog Dendrobates pumilio has weather can be deadly to them. Physalaemus nattereri has eye spots on its hind quarters. Saving endangered amphibians Illustration by Jacqueline Mahannah. Reproduced by To help many of the at-risk amphibians, governments, sci- permission. These may be national parks, preserves, or other natural areas. Many local, state, and national governments have also designed laws to protect the amphib- ians from being hunted or collected.
In a few cases, conserva-. An extinct species is one that is no longer in existence. Leopard frogs with missing, deformed or extra legs started appearing near St. Albans Bay of Lake Champlain in St. Albans, Vermont. Biologists are not sure if pollution, a parasite, disease, or something else is causing the frogs to develop abnormally. In addition, the IUCN lists one frog as Extinct in the Wild, which means that it is no longer alive except in captiv- ity or through the aid of humans. Books: Behler, John. New York: Simon and Schuster, , Clarke, Barry.
New York: Dorling Kindersley, Florian, Douglas. Discovering Frogs. Halliday, Tim, and Kraig Adler, eds. New York: Facts On File, Harding, J. Amphibians and Reptiles of the Great Lakes Re- gion. Lamar, William. Tampa, FL: World Publications, Maruska, Edward. Amphibians: Creatures of the Land and Water. New York: Franklin Watts, Miller, Sara Swan. Frogs and Toads: The Leggy Leapers. New York: Dorling Kindersley Publishing, Periodicals: Hogan, Dan, and Michele Hogan. Masibay, Kim Y. Sunquist, Fiona.
Stoddard, Tim. Trivedi, Bijal P. A vertebrate subclass is an animal with a spine, or backbone. Most of the frogs are about 1. Some are much smaller. The smallest species are the Brazilian two-toed toadlet and the Cuban Iberian rain frog, which only grow to about 0. These compare with the unusually large Goliath frog, which can grow to Depending on the species, the skin on a frog may be smooth, somewhat bumpy, or covered with warts.
Although many people think that all warty frogs can be called toads, only those in one family of frogs are true toads. The members of this family typically have chubby bodies, rather short hind legs, and. This tiny organ does not appear to do anything in a healthy male toad, but it does help scientists tell a true toad from all other kinds of frogs.
A great number of frogs are green, brown, gray, and other colors that look much like the background in the place they live. They also have spots, stripes, and other patterns that help them blend into their surroundings. Many of the poison frogs, among others, are not camouflaged. They have bright colors that make them very noticeable.
Most species of frogs lay eggs that hatch into tadpoles. Tad- poles are sometimes described as a sack of guts with a mouth at one end and a tail at the other. Often, the mouth on a tad- pole is hard like the beak of a bird and is able to scrape bits of plants off the sides of underwater rocks. Some tadpoles instead have a fleshy mouth. These tadpoles suck in water and strain little bits of food out of it. Including their tails, tadpoles are of- ten as long as or longer than the adult frogs.
As the tadpoles change into young frogs, however, the tail slowly becomes shorter and shorter until it is gone. They do not live in ex- tremely cold areas, such as the Arctic, or on many of the is- lands out in the ocean. The largest number of frog species is in hot and humid tropical areas, but some make their homes in places that have all four seasons, including a cold winter.
Frogs usually stay out of very dry areas, but the water-holding frog and a few others are able to survive in dry grasslands and even deserts. The majority of frogs live in valleys, lowlands, or only partway up the sides of mountains. Some, however, survive quite well high above the ground.
The Pakistani toad is per- haps the highest-living frog. It makes its mountain home at 16, feet 5, meters above sea level in the Himalayas. HABITAT The majority of frogs start their lives in the water as eggs, then hatch into tadpoles, which remain in the water until they turn into froglets. At that point, frogs of some species may leave. Some species are able to survive without ever hav- ing to even dip their feet in a puddle. Most of these frogs spend hours everyday underground or in some other moist place.
A number of frog species that live in dry areas, such as grass- lands or deserts, stay underground and enter a state of deep sleep, called estivation es-tih-VAY-shun for much of the year. There, they wait for the rainy season and then climb back up to the ground to eat and to mate. Other frogs that live in colder places that have a frigid winter find shelter, sometimes also un- derground, and also enter a state of deep sleep, called hiber- nation high-bur-NAY-shun. They remain in hibernation until warmer weather arrives in the spring. DIET Most frogs eat mainly plants when they are tadpoles and switch to a diet of mainly insects once they turn into froglets.
Some tadpoles also eat little bits of dead animal matter that float down to the bottom of the water, and the tadpoles of a few species will even eat an insect or other invertebrate in-VER- teh-breht , which is an animal without a backbone. Not all adult frogs will only eat insects.
Many of the larger species will gulp down anything they can catch and swallow. Bullfrogs, which are common throughout much of North America, are one type of frog that will almost eat anything that comes within reach, including ducklings and other bullfrogs. Most frogs are ac- tive at night, which is when the air is more humid. Humid air helps them keep their skin moist. During the daytime, these frogs sit still in moist places, like under a rotting log, in a muddy place, underground, or in the crack of a rock. Even when frogs are active at night, they spend a good part of the time sitting still.
This is how many species hunt. They remain in one place and wait for an insect or other prey animal to wander past, ei- ther grasp it with their mouths or flick out their tongues to snatch it, and swallow it whole.
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Most frogs have sticky tongues that attach in the front of the mouth and flip outward. Some frogs, including the poison frogs, take a more energetic ap- proach to hunting, and hop about looking for their next meals. Those that live in warm, humid places may mate any time of year but usually only do so during or after a rainstorm. For species in espe- cially dry areas, the rainy season is the time In the s, scientists noticed that the for mating.
The males of almost all frog number of frogs around the world was species call during the mating season. They dropping. Some species were nearly gone, make the calls by sucking in and letting out and others were already extinct. They began air from the vocal sac, which is a piece of bal- trying to figure out why and now believe that loon-like skin in the throat area. Most frogs, many things may be to blame, including air like the spring peeper, have one vocal sac, but and water pollution, habitat destruction, some species, including the wood frog, have and infection with a fungus, called chytrid two.
The males of each species have their own KIT-rid fungus. They also believe that calls. The calls not only attract females but introduced species are a danger to frogs. In a few species, without thinking about what will happen to calls may not be enough, and two males may the frogs that use the water, too. In many fight. Most fights are little more than cases, fish eat frog eggs, tadpoles, and wrestling matches, but in some species, like sometimes adult frogs. Just a few fish in a the gladiator frogs, males have sharp spines pond may be enough to gobble up every and often injure one another.
In many frog frog egg and tadpole for the whole season. Since most adults only live and breed for a This type of group calling is called a chorus few years, the fishes can quickly wipe out KOR-us. In some species, the males all call an entire frog population. Frogs that breed over such a short time are called explosive breeders. To mate in most species, the male scrambles onto the back of a female in a piggyback position called amplexus am-PLEK- sus and hangs onto her. As she lays her eggs, he releases a fluid. The fluid contains microscopic cells called sperm that mix with the eggs.
Once fertilization happens, the eggs begin to develop. The tailed frogs do things a bit differently. Depending on the species, a frog may lay less than a dozen eggs at a time or more than a thousand. The typical female frog lays her eggs in the water, often in underwater plants, and she. In a few species, one of the parents stays behind to watch over the eggs and sometimes stays to cares for the tadpoles, too.
The typical frog egg develops in the water into a tadpole. In some species, the egg develops instead in a moist spot, and in a few species that moist spot is inside a pouch or on the back of one of the parents. A number of the frogs that have their young on land lay eggs that skip the tadpole stage and hatch right into baby frogs. In most frogs, however, the eggs hatch into tadpoles that continue growing in the water.
Most tadpoles begin to change into froglets within a month or two, but some remain tadpoles for a year or more. The change from a tadpole to a froglet is called metamorphosis meh-tuh-MOR-foh-sis. Soon a tiny froglet, often still with a little bit of the tail left, takes its first hops. In some places, people even gather to- gether to listen to frog choruses.
Some people eat frogs, espe- cially frog legs, and occasionally tadpoles. Frogs are also popular as pets. Perhaps more importantly, some frogs have chemicals in their skin that are helping to treat human med- ical conditions. In addition, scientists are watching frog popu- lations very closely, because frogs can help them tell whether the environment is healthy. A population that suddenly disap- pears from a pond, for example, may be a warning sign that the water is polluted. New York: Simon and Schuster, Inc. Amphibians and Reptiles of the Great Lakes Region.
Grzimek's student animal life resource, Amphibians - Anaheim Public Library
Walters, Mark Jerome. Morell, Virginia. They have little or no webbing between the toes on order their front or hind feet. Their four feet also have smooth soles, monotypic order a feature that sets them apart from similar species living in New Zealand, which have pads or suckers on their feet. New Zealand suborder frogs are usually brown, but some are green or reddish brown. These bumps are called granular GRAN-yoo-ler glands. When a predator bites one of these frogs, the poison in the glands oozes out, which may cause the predator to spit out the frog, and possibly learn to leave the frogs alone in the future, too.
New Zealand frogs grow to 0. Humans introduced, or brought in, the others, which include two species of bell frogs and a brown tree frog. Conservationists in intro- duced one of the four species to Motuara Island, where it is surviving. Some also survive among rocks and shrubs in a misty but almost treeless part of Stephens Island.
Zealand show that it once was home to many frogs—all in the family Leiopelmatidae. DIET These frogs, which have the fitting common These small frogs eat insects and other in- name of New Zealand frogs, included three vertebrates in-VER-teh-britts , which are species that lived on the islands until 1, animals without backbones, that live in their to 2, years ago, when they became habitat. Many species of frogs capture their extinct.
Today, four species from this family prey by flinging out their long tongues and still exist in New Zealand, but they live in using them to grasp. New Zealand frogs, on very small areas compared to the land the the other hand, cannot stick out their family once called home. Instead, a New Zealand frog must quickly lunge at a prey animal and grab it with its mouth. New Zealand frogs make almost no noise. They may offer a soft squeak if they are roughly handled or some faint squealing sounds during the mating season.
Otherwise, they remain silent and even stop moving if a person or some other possible predator comes close. In addition, these frogs are mostly nocturnal nahk-TER-nuhl , which means that they are active at night. The darkness also helps to hide the frogs from sight. Sometimes, however, predators are still able to find them. If the frogs have the chance to escape by jumping into the water, they will. They swim by kicking one leg at a time instead of kicking both hind legs together, as other frogs do. If they can- not escape a predator, three of the four species defend them- selves by raising up on their four legs so they are as tall as possible and turning their bodies to face the predator.
This puts. Scientists are especially interested in During mating season, most species of New Zealand frogs because they have some frogs find one another by either making loud very primitive features, including extra calls, in the case of the males, or responding backbones and muscles that are designed to those calls, as the females do. Since New to move tails. Since the frogs have no tails, Zealand frogs do not call and even lack a real scientists believe the tail-wagging muscles voice box, scientists think that they find each are left over from long-extinct ancestors of other by their smells instead.
The female lays these species. The only other living frogs five to 20 eggs, depending on the species. The with these features are frogs of the family developing frog is visible inside the see- Ascaphidae. The extra backbones are also through egg capsule. The fossils date back to about through a short tadpole stage before becom- million years ago, which means the frogs ing frogs.
These frogs go through their tadpole stage while still inside the eggs, so the eggs hatch right into tiny frogs. The male in all three of these species stays with the eggs until they hatch, often covering them with his body. He continues to protect newly hatched young by letting them climb onto his back and legs. Strict laws are now in place to protect the frogs and the places they live.
They were once much more common, but when scientists counted them in and again in , they found that their num- bers fell by 80 percent: four out of every five frogs had disap-.
In one population, the number of frogs went from individuals to just The cause of the drop was probably dis- ease, possibly caused by a fungus. Scientists first became aware of the fungus, called chytrid KIH-trid fungus, in Australia and Central America in and have since blamed it for the de- clines of many frog species.
The fungus is still a problem. When the fungus infects one of these frogs, it has trouble moving and soon becomes paralyzed. The major threats to these species are introduced predators, including rats and ermines, which are in the weasel family, and the lizard-like tuataras. In addition, scientists are keeping a watchful eye on these three species to see if the chytrid fungus eventually affects them, too.
It also has a noticeable ridge running from the head down each side of the body. Its feet have no webbing between the toes. The frog grows to 2. Females are usually a bit larger than males. Geographic range: One of the rarest frogs in the world, it lives in a tiny area high atop Stephens Island in New Zealand. Habitat: Although its preferred habitat is likely moist forest, this species now survives in a damp, rocky pile that is covered mostly by grasses and shrubs.
Illustration by Brian Cressman. Behavior and reproduction: This frog, for the most part, remains out of sight during the day. Like the other New Zealand frogs, it does not call. It can, however, squeak if mishandled.
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Females lay five to nine eggs at a time on land. Each egg hatches into a tiny frog. The males watch over the eggs and young. Protection efforts are under way to protect its small home area and to help it survive into the future. At that time, they compared their DNA and found that the frogs were different enough to be separated into two species.
DNA, which is inside the cells of all animals, is a chain of chemical molecules that carry the instructions for creating each species and each individual. When looking at the frogs from the outside, the biggest difference between the two species is their color: the Maud Island frog is paler, but only slightly. They both have unwebbed feet and ridges on the back, and each grows to 2. Females are a bit larger than males. Geographic range: It lives on a tiny scrap of land, measuring just 0. In , conservationists gathered individuals and transplanted them to Motuara Island, where the frogs seem to be surviving well.
Habitat: This frog makes its home in the forest that covers the east side of a hill on Maud Island. Although the forest reaches up the hill to about feet meters , the frog tends to live in the lower portion, where the slope is flatter and the climate is more moist. This species often hides among rocks and logs. Behavior and reproduction: The Maud Island frog stays out of sight during the day and comes out at night to hop slowly about and look for food. Female Maud Island frogs lay their eggs, which can num- ber up to 20, in damp spots on the forest floor.
Each male watches over his eggs until they hatch into tiny frogs. He allows the froglets to climb up his legs and onto his back. Conservation status: According to the World Conservation Union, the Maud Island frog is Vulnerable, which means that it faces a high risk of extinction in the wild. The current major threat to this species is introduced predators, including rats and ermines. Efforts are un- der way to keep the predators away from the frogs. Shine, and H. Ehmann, eds. The Biology of Australasian Frogs and Reptiles. Hutching, Gerard. Auckland: Penguin, Jones, Jenny.
Auckland: Heinemann Education, Robb, Joan. New Zealand Amphibians and Reptiles in Color. Auckland: Collins Publishers, Web sites: Barnett, Shaun. Kingsley, Danny. Lehtenin, R. Both have wide heads and large eyes with monotypic order vertical, often diamond-shaped pupils. Unlike many other frogs, they have no round patch of an eardrum showing on the sides suborder of the head. The frogs are usually shades of brown or gray, sometimes with a hint of green or red, and have darker markings, includ- ing blotches on the back and bands on all four legs.
A lighter- colored patch, usually outlined with a thin, dark stripe, stretches between the eyes. Once in a while, a tailed frog may be almost completely black. The underside is pink, sometimes speckled with white. Tailed frogs have slender forelegs with no webbing on the toes and larger hind legs with well-webbed toes. Their toes, especially the outside toe on each foot, are quite wide. Adult tailed frogs are small, growing only to 1.
The females are a bit bigger than the males. The tailed frog tadpole is dark gray and has a large, telltale sucker on the bottom of its broad head. Like other frogs, the tadpole has a long tail. When it begins to change into a frog, the tail shrinks until it disappears altogether. Often, people see an adult male tailed frog and believe that it is just a froglet that still has. This is not correct. The fleshy nub on an adult male tailed frog is different from a tadpole tail and never disappears. Two species of tailed frogs exist: the Rocky Mountain tailed frog and the coastal tailed frog.
The DNA of the Rocky Mountain tailed frog and the coastal tailed frog were just different enough to separate them into two species. Both of these frog species have very small lungs, compared to most other frogs, and have extra backbones. Only one other living group of frogs, the New Zealand frogs, has the same ex- tra backbones. Scientists have found fossil frogs far in the past that had the extra bones.
These date back to the dinosaur age million years ago and are the oldest known frogs. The Rocky Mountain tailed frog makes its home in Idaho, western Montana, southeastern Washington, northeastern Oregon, and the most southeastern portion of British Columbia. When they are in the fast current, they breathe mainly through their skin and do not have to rely on their lungs as much.
Human beings get their oxygen by breathing air into the lungs. There, blood picks up the oxy- gen out of the air and delivers it through blood vessels to the rest of the body. Frogs can get their oxygen from the water. Water, also known as H2O, is made up of two chemicals: hy- drogen and oxygen.
The H2 means two atoms of hydrogen are in every molecule of water, and the O means one atom of oxy- gen is in each molecule. The water runs past the frog, and blood vessels near the surface of its skin take up the oxygen. This arrangement allows the frog to survive even though it has very small lungs. On land, the frogs continue to breathe through the skin, which they must keep moist, but they are also able to take up some oxygen from the air through their lungs, as people do.
DIET Adult tailed frogs eat insects, snails, and other invertebrates in-VER-teh-brehts , which are animals without backbones, that they find either in the water or on land nearby. Tailed frogs do not have long tongues that flip far out of their mouths to nab prey.
Rather, they have short tongues that are of little use for catching passing invertebrates. They are able to capture prey by remaining still and waiting for an insect or other prey ani- mal to come just close enough that the frog can quickly jump out and grab the insect with its mouth. Tadpoles get their food another way. Tadpoles use the strong sucker around the mouth to cling to underwater rocks and avoid being swept away by the current. While they are hanging on, they scrape up and eat bits of algae AL-jee with their rows of tiny teeth.
Algae are tiny plantlike organisms that live in water and lack true roots, leaves, and stems. At night, especially dur- ing or after a rain, they hop about on land near the stream to look for food. They still must keep their skin moist while they are out of the water, because dry skin prevents them from tak- ing up oxygen from the air.
They move about on land by hop- ping and in the streams by sweeping their strong hind feet as they swim through the water. When in the water, they tend to stay in areas where overhanging trees cast shadows. Newly hatched tadpoles, which are almost see-through compared to the darker, older tadpoles, remain in slower water, often in small side pools where the current is calmer. The larger tad- poles, however, brave the strong current by using their large suckers to attach tightly to rocks.
These small frogs mate in the fall. They do so quietly be- cause male tailed frogs do not call, as the males of most other frog species do. During the breeding season, the males grow black pads on their front feet and small black bumps on their. These pads and bumps help the male grab and hang onto the back of a female during mating. In the case of the tailed frogs, the mixing of the eggs and sperm cells hap- the pads are black, but they can be other pens outside her body. A male tailed frog, colors, too. Called nuptial NUHP-shul however, fertilizes the eggs differently.
The female then back, is called amplexus am-PLEK-sus. When hold onto the female up by her forelegs, a she does lay them, her eggs are already fer- position that is called axial ACK-see-uhl tilized. The other type of front of her hind legs in a position called fertilization, which happens outside the body inguinal ING-gwuh-nuhl amplexus. A female tailed frog can lay 35 to eggs at a time. She lays her eggs underwater, sticking them under rocks and usu- ally in an area of the stream where the current is slower, so the eggs are not swept away downstream.
The eggs hatch about six weeks later into small, colorless tadpoles, which soon develop the mouth suction cups and grow into larger, dark-colored tad- poles. They may remain tadpoles for five to seven years before they finally turn into small froglets. They usually switch from tadpole to froglet in the spring or summer. The froglets may need another 3 to 8 years before they are adults themselves. This is unusual. Most other species of frogs go from egg to tad- pole to froglet to adult frog in a shorter amount of time, often within a single year.
The tailed frogs not only take a much longer time to develop, but they also stick around longer overall. They often live in the wild to the ripe old age of 15 or. Through their long lives, tailed frogs remain near the spot in the stream where they were born. However, they are actu- ally quite plentiful in their habitat.
Conservationists continue to keep watch over the frogs, however, because they must have clean and clear streams to survive. Or- ganizations in Canada, in particular, have begun protecting the habitat of this frog. Physical characteristics: The Rocky Mountain tailed frog is a medium-sized brown to brownish black, sometimes gray, frog with tiny black specks.
A lighter brown patch spreads between the large eyes, often dipping down toward the rounded snout. Its belly is pink. Adults of both the Rocky Mountain tailed frog and the coastal species usually grow to 1. Illustration by Dan Erickson. Habitat: Rocky Mountain tailed frogs live in mountain forests near and often in small, clear, rocky-bottomed streams with fast currents.
Diet: They eat insects and other invertebrates they catch in the wa- ter or on land nearby. They look for food at night. Tadpoles are veg- etarians and use their small teeth to scrape algae AL-jee , or microscopic plantlike organisms, off underwater rocks. Behavior and reproduction: Active mainly at night, they spend their days hidden under rocks along the shoreline. They mate in the fall, and each female lays 45 to 75 eggs in the water the following sum- mer. The eggs hatch into tadpoles, which may remain in that state for up to five years. Finally, the tadpoles turn into froglets, and an- other seven or eight years later, they are adults.
In the wild, the frogs may live to be 15 to 20 years old. Rocky Mountain tailed frogs and people: Scientists find both species of tailed frogs interesting because they have some features of the earliest known frogs that hopped the Earth at the time of the di- nosaurs, and they mate differently from most other frogs alive today. The Committee on the Status of Endangered Wildlife in Canada, however, lists it as Endangered, which means that it may soon disappear. Books: Corkran, Charlotte.
- | Rutgers University Libraries.
- Europe from a Backpack: Real Stories from Young Travelers Abroad?
- Mammology: Selected Resources;
Amphibians of Oregon, Washington, and British Co- lumbia. Nussbaum, R. Brodie, and R. Amphibians and Rep- tiles of the Pacific Northwest. Moscow: University of Idaho Press, Stebbins, Robert C. Boston: Houghton Mifflin, Wright, A. Ithaca, NY: Comstock, Mierzwa, Ken. Thompson, Don. They are named for these flame-like colors, which have black or gray spots, order blotches, and patterns running through them. The barbourulas are also colored in muddy greens and browns, but they do not have the flashy undersides of the fire-bellied toads. Members of this family have skin on their backs that is cov- ered with warts and sometimes with pointy warts that look like tiny spikes.
The belly skin, in contrast, is much smoother and in most cases has no warts at all. The head has a rounded snout and two large eyes with triangular pupils, and the sides of the head do not have the round eardrums, or tympanums tim- PAN-umz seen in many other frogs. The frogs are small- to medium-sized. Adults grow from 1. Males and females look alike, except that the males have leathery pads on their front feet. The males use these pads to clutch onto the females during the mating season.
Even though the fire-bellied toads and barbourulas are often listed as being in their own family, some people prefer to group. Other scientists like to split them into still different arrangements. Scientists are not sure which is best, but most lean toward the family as it is described here. Some species also live far- ther south in Vietnam, Borneo, and the Philippines.
The fire-bellied toads prefer marshy areas, or small, often shallow ponds, where the water has little if any current. The barbou- rulas, on the other hand, like the faster-moving water of moun- tain streams and small pools of water that have plenty of rocks to provide hiding places.
These can include worms and snails, as well as beetles and other insects. The tad- poles of many species will eat insects, too, but usually fill their stomachs mostly with algae AL-jee , plants, and fungi. Unlike many other types of frogs and toads, the members of this fam- ily do not have tongues they can flip out of their mouths to capture prey. Instead, they must lunge at prey and grab their meals with their mouths. This means that a fire-bellied toad, for example, must get close to its prey so it can leap and catch the insect before it can run or fly away. The frogs have glands in the warts down their backs that can release a bad-tasting, white and foamy ooze that is also slightly poisonous.
When the frog feels threat- ened, possibly by a predator that comes too close, it flips over, arches its back, stretches out its back legs, and reaches its forelegs up. Sometimes, the frog stays on its belly, but arches its back and spreads its legs. Both of these unusual displays. Scientists call this odd back bend an unken OONK-en re- flex. The unken reflex and the colors it dis- plays remind the predator that this frog does not make a good snack. For example, a shorebird stay away by bending up their bodies to known as a night heron may get as much as show off their brightly colored undersides.
The bright colors are an advertisement to The two main types of frogs in this the predators that the frog has a nasty family—the fire-bellied toads and the taste. Many other bad-flavored frogs and barbourulas—lead very different lives. The salamanders also bend in this way. Compared to the fire-bel- German word for fire-bellied toad. A reflex lied toads, the barbourulas are very shy. People have These frogs stay out of sight, usually hiding reflexes, too, such as blinking or twitching among rocks in the water. When barbouru- at sudden noises.
This camouflage, their secretive behavior, and the small numbers of this species that exist have made barbourulas difficult to study, and scientists still know little about them. The mating season for many of the fire-bellied toads starts in late spring and continues into the middle of summer, and some may breed two or three times a year. Unlike the males of other types of frogs, which call only during certain times of the day, male fire-bellied frogs sing at any time, even though they only mate with the females in the evening hours.
Males mate with fe- males by grabbing onto their back so they look as if they are rid- ing them piggyback. This puts the male in the right position to fertilize FUR-teh-lyze her eggs as she releases them. During the mating season, a male will sometimes mistakenly grab onto a sec- ond male instead of a female. The second male frantically tries to squirm away, sometimes making a croaking squeal, known as a release call. People sometimes use this mating behavior as a quick way to tell the males from the females: During the mating sea- son, those toads that climb onto the backs of others are likely to be males, and those who do not try to squirm away when another.
Just because a toad tries to get away does not necessarily mean that it is a male, however, because females who are not ready to mate will also try to escape the clutch of a male toad. She usually drops them in advertise to predators that they taste bad. Some frogs lay their predators learn what the colors mean. How eggs in permanent bodies of water, like does a predator learn?
When a young streams or ponds that never dry up, but predator finds one of these frogs for the first others lay their eggs in temporary pools of time, it only sees what it thinks is an easy water that disappear in dry summer months. When it takes the frog into its mouth, In about a week, sometimes longer, the eggs however, the frog oozes an unpleasant- hatch into tadpoles.
In another six weeks or tasting poison from its skin, and the so, the tadpoles turn into baby frogs. The surprised predator quickly spits it out. If they can- but often it survives. In either case, the not change into toadlets before the water dis- predator has learned a lesson to stay away appears, they may dry up and die.
This is why many poisonous than the fire-bellied toad. She lays her eggs— animals have bright colors, especially red. Many of these frogs can live more than ten years in captivity. Four are Vulnerable,. These are the Philippine barbourula, the large-spined bell toad also known as the Guangxi fire-bellied toad , the Lichuan bell toad, and the small-webbed bell toad also known as the Hubei fire-bellied toad. The biggest threats to these frogs include pol- lution, habitat destruction, and collection for the pet trade.
In addition, some are extremely rare. The large-spined bell toad, for example, is so uncommon that scientists have only found a few individuals and only in a small part of China. Fortunately, most of this area is protected inside a national nature reserve. Likewise, the Lichuan bell toad only appears to live in ten lo- cations inside two Chinese provinces, and the habitat in many of these areas is being destroyed as new farms and homes move in.
At least one of these populations, which makes its home in- side a nature reserve, is protected. The fifth of the five at-risk species is the Bornean flat-headed frog. This species is Endangered and faces a very high risk of extinction in the wild. The Bornean flat-headed frog lives in a single, tiny area that measures less than miles by miles kilometers2 , and scientists know about it from just two individuals collected from forest rivers. Unfortunately, human activity near the rivers, including illegal gold mining, is mak- ing the rivers muddy and polluted, which may hurt the frogs that still live there.
Although the other five species in this family are not listed as being at risk, scientists are watching them closely because some groups of these frogs are disappearing. Human develop- ment in the habitat of the fire-bellied toad is wiping out entire populations of this animal. Physical characteristics: When seen from above, fire-bellied toads also known as European fire-bellied toads are usually dark gray or black with large black markings. When they live in places with green, leafy areas, they typically have dazzling lime-colored backs that are dec- orated with black spots.
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