Amphibian

VHS cover

*Amphibian* is the seventh episode of the first season of Eyewitness. The topic of the episode is about the major amphibian groups, their survival strategies and their relationship with humans. The episode first aired on 19th September 1994.

Amphibian is based on a book title that was first published in 1993, and has been republished on several occasions including in 2000 and 2005.

## Episode

### Introductory sequence

An animated cycle shows frogspawn hatching into tadpoles, then two tadpoles swimming, followed by the tadpoles growing legs and finally a real strawberry poison-dart frog hops into and then out of shot, leaving the white background.

### Episode outline

Click here for the full transcript for Amphibian.

Amphibians have long been a source of eerie fascination for humans. Amphibian means double life, which reflects their life cycle. An amphibian completes, in twelve weeks, the evolutionary progress from water to land that took humans millions of years.

There are three main groups of amphibians. The newts, salamanders and sirens have legs and tails, the caecilians lack legs and the frogs and toads have legs but no tail. They can live in a huge variety of habitats. Frogs and toads are the best-known amphibians, but have some differences – frogs are better at jumping. This has been put to use in frog-jumping competitions.

All amphibians have porous skin, which means they must live near to water. They can serve as barometers for local conditions. The water-holding frog outlasts drought inside a special mucus bag. Other frogs have different means of keeping the sun from damaging their fragile skin.

The tadpole continues to grow, and at this stage its senses are developing. Frogs and toads have excellent senses of hearing, and use sound to attract a mate. Amphibians also use their strong eyesight, reflected in the number of different shapes their pupils come in. A frog only sees in black and white. Some frogs have a disappearing act, with skin that matches perfectly the leaves they sit on to avoid sharp-eyed hunters.

Frogs use colour in many ways to avoid predators. Some use camouflage to disappear into the background, while poison-dart frogs use bright colour to advertise the fact that they possess some of nature’s deadliest weapons.

At six weeks old, the tadpole is growing its back legs. The skins of frogs and toads have been used by humans – toad poison is an ingredient in the spells of witches, Choco Indians tip their arrows with poison-dart frog toxin and new antibiotics have been discovered on frog skin.

Frogs have many natural predators and so have developed many different defences. Some toads will puff themselves up to make themselves look too big to eat, some frogs have false eyes and the fire-bellied toad and some salamanders will twist themselves into strange shapes that display their danger colours. People once believed salamanders were born from fire. Some frogs can survive being frozen solid. Humans will sometimes eat frogs.

Frogs will eat almost anything that is alive and moving. They have a long and sticky tongue, and have to blink to swallow their food. The biggest appetite of any amphibian is the African bullfrog, with one recorded eating 14 baby cobras in a single meal.

At nine weeks old, the baby is now a miniature frog. Some salamanders become adults only when the weather shifts. Salamanders move with a fish-like S-wriggle, while frogs move in water using a frog-kick. Some frogs live in trees, but still need access to water for breeding and so build nests of foam above a body of water. A few frogs use their webbed feet to glide.

Frogs and toads are often thought of as ugly or evil creatures. A woman in 16th century England found with a toad in her house would be tried for witchcraft. There have been countless stories of toads being found hiding inside rocks, which is attributed to hibernation. Toads also migrate long distances to return to the pond of their birth. The greatest toad army ever is that of the cane toad sweeping through Australia. The toad returns to its birth pond to breed itself.

Amphibian reproduction is the explored. Frogs and toads croak to attract a mate, while the vampire salamander bites an aphrodisiac into his mate’s neck. Some amphibians lay a clutch of one egg, while others can lay thousands. Some amphibians make caring parents, such as the Surinam toad, the Siberian salamander and the Darwin’s frog, which rears its young inside its mouth.

After twelve weeks, the amphibian has become a creature of the land. It reflects how, from the amphibian, all reptiles, birds and mammals evolved. We can almost understand those ancient Egyptians who believed that frogs were partially-formed humans and that this was simply the human embryo. For in evolution, so it was.

## Animal species filmed for the programme

### Studio footage

* Strawberry poison-dart frog, *Oophaga pumilio*
* European brown common frog, *Rana temporaria*
* Tiger salamander, *Ambystoma tigrinum*
* African bullfrog, *Pyxicephalus adspersus*
* Red-eyed tree frog, *Agalychnis callidryas*
* Fire salamander, *Salamandra salamandra*
* Cranwell’s horned frog, *Ceratophrys cranwelli*
* White’s tree frog, *Litoria caerulea*
* European green toad, *Bufotes viridis*
* Emperor newt, *Tylototriton shanjing*
* Rough-skinned newt, *Taricha granulosa*
* Alpine newt, *Ichthyosaura alpestris*
* Cane toad, *Rhinella marina*
* Common tree frog, *Polypedates leucomystax*
* African red toad, *Schismaderma carens*
* European tree frog, *Hyla arborea*
* American bullfrog, *Lithobates catesbeianus*
* Oriental fire-bellied toad, *Bombina orientalis*
* Beauty rat snake, *Orthriophis taeniurus*
* Dyeing poison-dart frog, *Dendrobates tinctorius* – including blue morph ‘*azureus’*
* Lehmann’s poison-dart frog, *Oophaga lehmanni*
* African lungfish, *Protopterus annectens*
* American green tree frog, *Dryophytes cinereus*
* Domestic dog, *Canis familiaris*

### Stock footage

* Surinam toad, *Pipa pipa*
* Siberian salamander, *Salamandrella keyserlingii*
* Waxy monkey leaf frog, *Phyllomedusa sauvagii*
* Ringed caecilian, *Siphonops annulatus*
* Common tree frog, *Polypedates leucomystax*
* Marsh frog, *Pelophylax ridibundus*
* Tree frog, Hylidae
* Pool frog, *Pelophylax lessonae*
* American bullfrog, *Lithobates catesbeianus*
* Water-holding frog, *Ranoidea platycephala*
* Red-eyed tree frog, *Agalychnis callidryas*
* Puerto Rican coqui, *Eleutherodactylus coqui*
* Ornate horned frog, *Ceratophrys ornata*
* Dwarf clawed frog, *Hymenochirus sp*.
* Malayan horned frog, *Pelobatrachus nasutus*
* Yucatan casque-headed tree frog, *Triprion petasatus*
* Golden poison-dart frog, *Phyllobates terribilis*
* Blue-spotted mudskipper, *Boleophthalmus boddarti*
* Fringe-lipped bat, *Trachops cirrhosus*
* Common opossum, *Didelphis marsupialis*
* European common toad, *Bufo bufo*
* Barred grass snake, *Natrix helvetica*
* Oriental fire-bellied toad, *Bombina orientalis*
* Tiger keelback snake, *Rhabdophis tigrinus*
* Cuyaba dwarf frog, *Physalaemus nattereri*
* Rough-skinned newt, *Taricha granulosa*
* Wood frog, *Lithobates sylvaticus*
* Tiger salamander, *Ambystoma tigrinum*
* Smooth-sided toad, *Rhaebo guttatus*
* Common spadefoot toad, *Pelobates fuscus*
* Bombardier beetle, *Brachinus sp*.
* African bullfrog, *Pyxicephalus adspersus*
* Indian cobra, *Naja naja*
* Axolotl, *Ambystoma mexicanum*
* Grey foam-nest frog, *Chiromantis xerampelina*
* Gliding tree frog, *Agalychnis spurrelli*
* Sprinkled long reed frog, *Hyperolius adspersus*
* Banded rubber frog, *Phrynomantis bifasciatus*
* European tree frog, *Hyla arborea*
* Northern dusky salamander, *Desmognathus fuscus*
* European brown common frog, *Rana temporaria*
* Sabana Surinam toad, *Pipa parva*
* Darwin’s frog, *Rhinoderma darwinii*
* Rain frog, *Pristimantis sp*.

## Stock footage sources

Nosferatu (1922) – Black-and-white vampire movie footage

Flip the Frog

* Puddle Pranks (1930) – Car horn frog cartoon
* The Soup Song (1931) – Fly in soup cartoon
* Orphan Willie (1930) – Singing frog cartoon

Wildlife on One: Amorous Amphibians (1980) - Pool frog

The Wind in the Willows (1983) – Stop-motion Mr Toad footage

The Trials of Life:

* Arriving (1990) – Rain frog eggs
* Hunting and Escaping (1990) – Horned frog and opossum, rough-skinned newt, Cuyaba dwarf frog, Yucatan casque-headed frog

Natural World: The Great Karoo – A Secret Africa (1991) – African bullfrog

Realms of the Russian Bear: Born of Fire (1992) – Fire-bellied toad and keelback snake, Siberian salamander

Killing for a Living: Dressing for Dinner (1993) – Spadefoot toad and bombardier beetle

## Credits

* Director - Perry Miller
* Graphics Director - Alisa Robbins
* Writer - David Hanson
* Script Supervisor - Brian Meehl
* Camera - Dominique Grosz
	+ Assistant - Andy Shillabeer
* Set Design - Ben Scott
* Production Manager - Peter Thornton
* Production Assistant - Lisa Garvin
* Production Secretaries - Cathy Wilkin and Caroline Elston
* Unit Manager - Grant Dean
* Researcher - Johanna Gibbon
* Picture Researcher - Martin Willis
* Research Assistant - Lisa Kendrick
* Graphic Design - 4:2:2 Videographics
* Editors
	+ Offline - Chris Godden
	+ Online - Sharon Stiles
* Dubbing Editor - Julie Mitchell
* Dubbing Mixer - Andrew Wilson
* Music - Guy Michelmore
* Executive Producer - Michael Bright,
* Special thanks to:
	+ Dr Scott Jones

## Making this programme

The exploding rock was shot in the Eyewitness studio. The rock was built from two fibreglass halves that were blown apart with compressed air. Dry ice helped create the right atmosphere, while a small explosive charge was placed in the rock to create the actual explosion. After several takes, the explosion was complete and the toads were placed in one half of the exploded rock. Fire was also used in this episode, with a small set made to represent the Eyewitness Museum in which several salamanders were filmed. Fire safety measures are outlined. The set had fire bars along either side and a flame cannon at the far end of the set. Although the salamanders were never near the flames, the illusion illustrated the myth of them being born from fire. The myth of the Princess and the Frog was reversed for this episode, with the princess turning herself into a witch when she kisses the frog.

## Home media releases

As well as being released on VHS, Amphibian was also released as part of the DVD release in the USA.

Amphibian America-release DVD cover

**Writing staff**: Anne MacLeod • Ben Southwell • Ben Steiner • Brian Meehl • David Hanson • David Stafford • David Helton • George Bloom • Lynette Singer • Mike Tomlinson • Paul Thomas • Stan Cullimore
**Directors**: Gavin Maxwell • Justine Kershaw • David Hutt • Andrew Jackson • Justin Hardy • Ludo Graham • Jerry Foulkes • Derek Hall • Sanjida O'Connell • Caius Julyan • Bonni Cohen • Leanne Pooley • Edwina Vardey • Alexandra Beazley • Sam Hodgkin • Karen Walsh • Jack Weber • Richard Simkin • Alex Hearle • Brian Cummins • Ben Southwell
**Composers**: Guy Michelmore (season one) • Guy Dagul (seasons two and three)

**Season One**: Cat • Fish • Horse • Dog • Jungle • Bird • **Amphibian** • Insect • Shark • Elephant • Reptile • Dinosaur • Skeleton
**Season Two**: Desert • Tree • Ape • Mammal • Butterfly and Moth • Volcano • Rock and Mineral • Seashore • Pond and River • Weather • Arctic and Antarctic • Prehistoric Life • Shell
**Season Three**: Flight • Bear • Sight • Island • Survival • Mountain • Monster • Human Machine - Plant • Ocean • Planets • Life • Natural Disasters