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More About Frogs ...
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A frog is a fresh-water amphibian of the family Ranidae, in the Order Anura. They are closely related to toads. The Ranidae are sometimes called the "true frogs" since a few members of other families also have common names including the word "frog.".
In many parts of the world the frog population has declined drastically over the last few decades. Pollutants are one cause for this decline but other culprits include climatic changes, parasitic infestation, introduction of non-indigenous predators/competitors, infectious diseases, and urban encroachment.
The life cycle of a frog involves several stages. A female frog lays her eggs in a shallow pond or creek, where they will be sheltered from the current and from predators. The eggs, known as frogspawn hatch into tadpoles. The tadpole stage develops gradually into an adolescent froglet, resembling an adult but retaining a vestigial tail. Finally the froglet develops into an adult frog. Typically, tadpoles are herbivores, feeding mostly on algae, whereas juvenile and adult frogs are rather voracious carnivores. Furthermore, The red-legged frogs normally reproduce from November to early April because during these months, the water is about six or seven degrees Celsius. Under these cool conditions, embryonic survival is ensured. Amplexus is the process wherein the male grasps the female while she lays her eggs. At the same time, he fertilizes them with a fluid containing sperm. The eggs are about 2.0 to 2.8 millimetres in diameter and are dark brown. After about six to fourteen days, the eggs hatch between July and September into brown tadpoles that are about three inches long. The tadpoles then progress to lose their tails, grow legs, and change into a juvenile form with adult characteristics.
Frogs eat insects such as mosquitoes and small animals such as minnows. Their sticky tongues are effective in catching fast-moving preys. They hunt mostly at night.
Frogs are a diverse group with some 4800 species. Most spend their lives in or near a source of water (water frogs), although tree frogs live in moist environments that are not actually aquatic. The requirement for water becomes most acute for egg and tadpole stages of the frog, yet here again some species are able to utilize temporary pools and water collected in the axils of plants.
The most familiar frogs are the Bullfrog, the Edible frog, the Leopard frogs, Spring Peepers, and the Green Frogs.
Frogs range in size from less than 50mm to 300mm in Conraua goliath, which is the largest known frog. All frogs have horizontal pupils, smooth skin and long legs with webbing between their toes. This family has a bicornuated tongue that is attached in front: They also have a tympanum on each side of their head, which is involved in sound production. Most frogs have deep, booming calls, or croaks, with some being onomatopoeically represented by the word "ribbet" or "ribbit."
Many species of frog secrete toxins from their skin when under threat. These toxins deter predatory animals from eating them, and some are extremely poisonous to humans. The natives of the Amazon area extract curare from the poison arrow frog.
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Taxonmony
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Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Ranidae
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Source: Wikipedia Read more about Frogs
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VIDEO CLIPS
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Frog
4.930MB MOV View Movie
Tropical Ecosystems of Costa Rica and Panama (R. Hays Cummins, Miami University)
A tree frog grips the bathroom wall at the OTS Field Station in Palo Verde.
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Frog
13.750MB MOV View Movie
Tropical Ecosystems of Costa Rica and Panama (R. Hays Cummins, Miami University)
A posion dart frog (Dendrobates sp. ) from Corcovado National Park. This male is calling for a mate. If you listen closely, you can hear the call above the background noise of the adjacent San Pedrillo river in Corcovado.
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Red-eyed tree Frog
Streaming RAM View Movie
National Geographic - Creature Feature Archive
It scares its predators with its red eye. Video of Red-eyed tree Frogs "But the awakened frog?s eyes pop open, revealing their startling bright red color".
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Frog
1.160MB MOV View Movie
Tropical Ecosystems of Costa Rica and Panama (R. Hays Cummins, Miami University)
Slideshow of frogs from Costa Rica. Really good clips of different species of frogs
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Goliath frog
MOV View Movie
Arkive.org
Nice selection of Goliath frog video clips available in various formats
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Southern corroboree frog
MOV View Movie
Arkive.org
Nice selection of Southern corroboree frog video clips available in various formats
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Southern gastric-brooding frog
MOV View Movie
Arkive.org
Nice selection of Southern gastric-brooding frog video clips available in various formats
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Poison Dart Frog
MOV View Movie
poison-frogs.com
Dendrobates Azureus film
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Red-eyed Tree Frog
0.300MB MOV View Movie
The Belize Zoo
Clip of Red-eyed Tree Frog
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Frog
Streaming RM View Movie
PBS
Frogs mating with narration
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poison arrow frog
3.440MB MPG View Movie
Martin's Reptiles
feeding
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Frog
0.570MB MOV View Movie
Creatas
Frog croaking at edge of pond
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Frog
0.340MB MOV View Movie
Creatas
Frog croaking in water
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Dendorbate Frog
0.360MB MOV View Movie
Creatas
Dendrobate frog croaking
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Frog
0.390MB MOV View Movie
Finley-Holiday Films
Frog
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Frog
1.740MB MOV View Movie
DVArchive
Large frog vibrating in pond, water vibrates too
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Frog
0.490MB MOV View Movie
DVArchive
Close up of frog face
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Green Tree Frog
1.750MB MOV View Movie
DVArchive
Large green tree frog, extremely close
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Frog
1.440MB AVI View Movie
ryc44
Frog
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Frog
MOV View Movie
The San Pedro River
A giant tadpole
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Frog
MOV View Movie
Autodax
Movie shows a predatory tadpole sucking in a small brine shrimp
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Poison Dart Frog
MOV View Movie
poison-frogs.com
Dendrobates Leucomelas male calling film
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Poison Dart Frog
MOV View Movie
poison-frogs.com
Dendrobates Tinctorius film
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Frog
20.120MB MOV View Movie
Australia Advances - CSIRO Publishing
Frog Killer
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Golden Mantella
0.500MB MPG View Movie
theBigZoo.com
Golden Mantella Eating
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Frog
1.650MB AVI View Movie
PhilaNet.com
Frog
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Frog
AVI View Movie
Close up shot of a tadpole showing beating heart
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Frog
AVI View Movie
Close up shot of a tadpole showing blood flow in the gills
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Bullfrog
View Movie
National Geographic
Bullfrogs Eat Everything
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Strawberry Poison Dart Frog
View Movie
National Geographic
Strawberry Poison Dart Frog
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Red-Eyed Tree Frog
View Movie
National Geographic
Red-Eyed Tree Frog's Life Cycle
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