Principal Grzimek's Student Animal Life Resource: Amphibians (3 Volume Set)
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Grzimek's Student Animal Life Resource: Amphibians (3 Volume Set)

Grzimek's Student Animal Life Resource: Amphibians offers readers comprehensive and easy-to-use information on Earth's amphibians. Entries are arranged by taxonomy, the science through which living things are classified into related groups. Each entry includes sections on physical characteristics; geographic range; habitat; diet; behavior and reproduction; amphibians and people; and conservation status. Family entries are followed by one or more species accounts and a range map and photo or illustration for each species. Entries conclude with a list of books, periodicals, and Web sites that may be used for further research.

Each volume of Grzimek's Student Animal Life Resource: Amphibians includes a pronunciation guide for scientific names, a glossary, an overview of amphibians, a list of species in the set by biome, a list of species by geographic location, and an index. The set has more than 200 full-color maps, photos, and illustrations to enliven the text, and sidebars provide additional facts and related information.

Volumes 1-3
ISBN 13:
DJVU, 12.70 MB
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grzimek's Student Animal Life Resource ••••

grzimek's Student Animal Life Resource •••• Amphibians volume 1 New Zealand frogs to Australian toadlets Leslie A. Mertz, PhD, and Catherine Judge Allen, MA, ELS, authors Madeline S. Harris, project editor Neil Schlager and Jayne Weisblatt, editors

Grzimek's Student Animal Life Resource: Amphibians Leslie A. Mertz, PhD, and Catherine Judge Allen, MA, ELS Project Editor Madeline S. Harris Editorial Stephanie Cook, Heather Price, Lemma Shomali Indexing Services Synapse, the Knowledge Link Corporation Rights and Acquisitions Margaret Abendroth, Timothy Sisler Imaging and Multimedia Randy Bassett, Michael Logusz, Dan Newell, Chris O'Bryan, Robyn Young Product Design Tracey Rowens, Jennifer Wahi Composition Evi Seoud, Mary Beth Trimper Manufacturing Wendy Blurton, Dorothy Maki © 2005 Thomson Gale, a part of the Thomson Corporation. Thomson and Star Logo are trademarks and Gale and UXL are registered trademarks used herein under license. For more information, contact Thomson Gale 27500 Drake Rd. Farmington Hills, MI 48331-3535 Or you can visit our Internet site at ALL RIGHTS RESERVED No part of this work covered by the copyright hereon may be reproduced or used in any form or by any means---graphic, electronic, or mechanical, including photocopying, recording, taping, Web distribution, or information storage retrieval systems---without the written permission of the publisher. For permission to use material from this product, submit your request via Web at permissions, or you may download our Permissions Request form and submit your request by fax or mail to: Permissions Thomson Gale 27500 Drake Rd. Farmington Hills, MI 48331-3535 Permissions Hotline: 248-699-8006 or 800-877-4253, ext. 8006 Fax: 248-699-8074 or 800-762-4058 While every effort has been made to ensure the reliability of the informa- tion presented in this publication, Thomson Gale does not guarantee the accuracy of the data contained herein. Thomson Gale acce; pts no payment for listing; and inclusion in the publication of any organization, agency, institution, publication, service, or individual does not imply endorsement of the editors or pub- lisher. Errors brought to the atten- tion of the publisher and verified to the satisfaction of the publisher will be corrected in future editions. LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA Mertz, Leslie A. Grzimek's student animal life resource. Amphibians / Leslie A. Mertz and Catherine Judge Allen, authors; Neil Schlager and Jayne Weisblatt, editors. p. cm. Includes bibliographical references and index. ISBN 0-7876-9407-X (set hardcover : alk. paper) --- ISBN 0-7876-9408-8 (volume 1) --- ISBN 0-7876-9409-6 (volume 2) --- ISBN 0-7876-9410-X (volume 3) 1. Amphibians---Juvenile literature. I. Allen, Catherine Judge. II. Schlager, Neil, 1966-- III. Weisblatt, Jayne. IV. Title. QL644.2.M4263 2005 597.8---dc22 2005015192 This title is also available as an e-book Contact your Thomson Gale sales representative for ordering information. Printed in Canada 10987654321

AMPHIBIANS: VOLUME 1 ReadersGuide...................................vii PronunciationGuideforScientificNames . . . . . . . . . . . . .ix WordstoKnow..................................xv GettingtoKnowAmphibians......................xxi Anura:FrogsandToads........................1 NewZealandfrogs..................................8 Tailedfrogs......................................17 Fire-belliedtoadsandbarbourulas....................25 Midwifetoadsandpaintedfrogs......................44 Mesoamericanburrowingtoad.......................56 ClawedfrogsandSurinamtoads......................62 Asiantoadfrogs....................................77 Spadefoottoads...................................94 Parsleyfrogs.....................................102 Ghostfrogs......................................110 Seychellesfrogs..................................117 Australiangroundfrogs............................124 Australiantoadletsandwaterfrogs...................139 SpeciesListbyBiome............................xli SpeciesListbyGeographicRange...................xlv Index.......................seetheCumulativeIndex AMPHIBIANS: VOLUME 2 ReadersGuide...................................vii PronunciationGuideforScientificNames . . . . . . . . . . . . .ix WordstoKnow..................................xv GettingtoKnowAmphibians......................xxi Leptodactylidfrogs................................153 Contents v Contents

Vocalsac-broodingfrogs...........................182 Three-toedtoadlets...............................190 Truetoads,Harlequinfrogs,andrelatives . . . . . . . . . . . . .198 Poisonfrogs.....................................218 Ruthven'sfrog...................................236 Glassfrogs......................................242 Amero-Australiantreefrogs.........................259 Truefrogs.......................................287 Squeakersandcricketfrogs.........................310 Shovel-nosedfrogs................................323 SpeciesListbyBiome............................xli SpeciesListbyGeographicRange...................xlv Index.......................seetheCumulativeIndex AMPHIBIANS: VOLUME 3 ReadersGuide...................................vii PronunciationGuideforScientificNames . . . . . . . . . . . . .ix WordstoKnow..................................xv GettingtoKnowAmphibians......................xxi Africantreefrogs..................................331 Asiantreefrogs...................................350 Narrow-mouthedfrogs............................368 Madagascarantoadlets.............................390 Caudata:SalamandersandNewts. . . . . . . . . . . . . . .398 Sirensanddwarfsirens............................403 Asiaticsalamanders...............................409 Asiatic giant salamanders and hellbenders . . . . . . . . . . . . .419 Pacificgiantsalamanders...........................427 Molesalamanders.................................433 NewtsandEuropeansalamanders....................440 Olmsandmudpuppies.............................461 Torrentsalamanders..............................471 Lunglesssalamanders..............................476 Amphiumas.....................................494 Gymnophiona:Caecilians.....................501 Americantailedcaecilians..........................506 Asiantailedcaecilians.............................511 Keralacaecilians..................................517 Buried-eyedcaecilians.............................522 Taillesscaecilians.................................527 SpeciesListbyBiome............................xli SpeciesListbyGeographicRange...................xlv Index.......................seetheCumulativeIndex Grzimek's Student Animal Life Resource vi

Grzimek's Student Animal Life Resource: Amphibians offers readers comprehensive and easy-to-use information on Earth's amphibians. Order entries provide an overview of a group of families, and family entries provide an overview of a particular family. Entries are arranged by taxonomy, the science through which living things are classified into related groups. Each en- try includes sections on physical characteristics; geographic range; habitat; diet; behavior and reproduction; animals and people; and conservation status. All entries are followed by one or more species accounts with the same information as well as a range map and photo or illustration for each species. Entries conclude with a list of books, periodicals, and Web sites that may be used for further research. ADDITIONAL FEATURES Each volume of Grzimek's Student Animal Life Resource: Amphibians includes a pronunciation guide for scientific names, a glossary, an overview of amphibians, a list of species in the set by biome, a list of species by geographic location, and an index. The set has 221 full-color maps, photos, and illustra- tions to enliven the text, and sidebars provide additional facts and related information. NOTE Grzimek's Student Animal Life Resource: Amphibians has standardized information in the Conservation Status section. The IUCN Red List provides the world's most comprehensive Reader's Guide vii Reader's Guide

inventory of the global conservation status of plants and ani- mals. Using a set of criteria to evaluate extinction risk, the IUCN recognizes the following categories: Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Conser- vation Dependent, Near Threatened, Least Concern, and Data Deficient. These terms are defined where they are used in the text, but for a complete explanation of each category, visit the IUCN web page at cats2001booklet.html. ACKNOWLEDGEMENTS Gale would like to thank several individuals for their assis- tance with this set. Leslie Mertz and Catherine Judge Allen wrote the text for the volumes. At Schlager Group Inc., Jayne Weisblatt and Neil Schlager coordinated the writing and edit- ing of the set. Special thanks are also due for the invaluable comments and suggestions provided by the Grzimek's Student Animal Life Re- source: Amphibians advisors: • Mary Alice Anderson, Media Specialist, Winona Middle School, Winona, Minnesota •Thane Johnson, Librarian, Oklahoma City Zoo, Oklahoma City, Oklahoma • Debra Kachel, Media Specialist, Ephrata Senior High School, Ephrata, Pennsylvania • Nina Levine, Media Specialist, Blue Mountain Middle School, Courtlandt Manor, New York • Ruth Mormon, Media Specialist, The Meadows School, Las Vegas, Nevada COMMENTS AND SUGGESTIONS We welcome your comments on Grzimek's Student Animal Life Resource: Amphibians and suggestions for future editions of this work. Please write: Editors, Grzimek's Student Animal Life Resource: Amphibians, U•X•L, 27500 Drake Rd., Farmington Hills, Michigan 48331-3535; call toll free: 1-800-877-4253; fax: 248-699-8097; or send e-mail via Grzimek's Student Animal Life Resource viii

Acanthixalus spinosus ay-kan-THICK-sal-us spy-NO-sus Adelotus brevis ay-deh-LO-tus BREH-vis Adenomus kandianus ay-deh-NO-mus kan-die-AY-nus Albericus siegfriedi al-BEAR-ih-kus SIG-freed-eye Alexteroon jynx ay-LEKS-tih-roh-on jinks Allophryne ruthveni ah-lo-FRYN rooth-VEN-eye Allophrynidae ah-lo-FRY-nih-dee Alytes obstetricans ah-LYE-tes ob-STET-trih-kanz Ambystoma tigrinum am-bih-STOH-ma tih-GRIH-num Ambystomatidae am-bih-stoh-MA-tih-dee Amphiuma tridactylum am-fee-U-ma try-DAK-tih-lum Amphiumidae am-fee-U-mih-dee Aneides lugubris ay-NEE-ih-deez lu-GU-bris Ansonia longidigita an-SOH-nee-aye lon-jih-DIJ-ih-ta Anura ann-UR-uh Arenophryne rotunda ah-ree-no-FRYN roh-TUN-da Arthroleptidae ar-throh-LEP-tih-dee Arthroleptis stenodactylus ar-throh-LEP-tis sten-oh-DAK-tih-lus Ascaphidae as-KAF-ih-dee Ascaphus montanus as-KAF-us mon-TAN-us Assa darlingtoni AY-suh dar-ling-TON-eye Atelognathus patagonicus ay-teh-log-NAYTH-us pat-ah-GO- nih-kus Atelopus varius ay-teh-LO-pus var-ee-us Atelopus vogli ay-teh-LO-pus vohg-lye Barbourula busuangensis bar-bo-RU-la bus-u-an-JEN-sis Pronunciation Guide for Scientific Names ix Pronunciation Guide for Scientific Names

Bolitoglossa pesrubra bo-LYE-toh-glos-sah pes-ROO-bra Bombina bombina BOM-bin-ah BOM-bin-ah Bombina orientalis BOM-bin-ah oh-ree-en-TAL-ihs Bombina variegata BOM-bin-ah vay-ree-GA-ta Bombinatoridae BOM-bin-ah-TOR-ih-dee Brachycephalidae brak-ee-sef-FAL-ih-dee Brachycephalus ephippium brak-ee-SEF-fal-us ee-FIP-ee-um Brachycephalus nodoterga brak-ee SEF-fal-us no-DOE-tur-ga Brachycephalus pernix brak-ee-SEF-fal-us PER-nicks Brachycephalus vertebralis brak-ee-SEF-fal-us ver-teh-BRA-lis Brachytarsophrys intermedia brak-ee-TAR-so-frys in-tur-ME- dee-uh Bufo marinus BOO-foe MAYR-ih-nus Bufo periglenes BOO-foe pair-ee-GLEH-nees Bufonidae boo-FOH-nih-dee Bymnophiona bim-no-fee-OH-nuh Caecilian seh-SILL-ee-uhn Caeciliidae seh-SILL-ee-eye-dee Caudata kaw-DAY-tuh Centrolene geckoideum SEN-troh-lean gek-oh-EYE-dee-um Centrolenidae sen-troh-LEN-ih-dee Ceratophrys cornuta seh-RAT-oh-fris kor-NEW-ta Chioglossa lusitanica chee-oh-GLOSS-ah loo-sih-TAN-ih-ka Cochranella ignota kok-ran-ELL-ah ihg-NO-ta Cochranella saxiscandens kok-ran-ELL-ah saks-ee-SKAN-denz Colostethus caeruleodactylus coh-loh-STETH-us see-RUE-lee- oh-DAK-til-us Conraua goliath kon-RAH-u-ah go-LYE-eth Cophixalus riparius co-FIX-ah-lus rih-PAIR-ee-us Cryptobranchidae KRIP-toe-BRAN-kih-dee Cryptobranchus alleganiensis krip-toe-BRAN-cus al-lee-GAY- nee-en-sis Cyclorana platycephala sy-klo-RA-na plat-ee-SEF-fa-la Cynops pyrrhogaster sy-NOPS pie-roh-GAS-ter Dendrobatidae den-droh-BA-tih-dee Dermophis mexicanus der-MO-fis meks-ih-KAN-us Desmognathus fuscus dez-mog-NATH-us FUS-cus Dicamptodon tenebrosus di-CAMP-toe-don ten-eh-BROH-sus Dicamptodontidae di-CAMP-toe-DON-tih-dee Discoglossidae dis-ko-GLOSS-ih-dee Grzimek's Student Animal Life Resource x

Discoglossus pictus dis-ko-GLOSS-us PIK-tus Edalorhina perezi ed-dah-LOR-heena PER-ez-eye Epicrionops marmoratus eh-pee-KREE-oh-nops mar-moh-RA- tus Epipedobates tricolor eh-pee-ped-oh-BA-tees tri-KUL-or Eurycea bislineata u-REE-see-uh bis-LIN-ee-ah-ta Eurycea rathbuni u-REE-see-uh rath-BUN-eye Gastrophryne carolinensis GAS-troh-fryn kay-roh-LIN-en-sis Gastrotheca riobambae gas-troh-THEH-ka ree-oh-BAM-bee Gymnophiona jim-no-fee-OH-nuh Heleophryne natalensis heh-lee-oh-FRYN nay-TAL-en-sis Heleophrynidae heh-lee-oh-FRYN-ih-dee Hemiphractus proboscideus heh-mee-FRAK-tus proh-BOSS- kid-day-us Hemisotidae heh-mee-SAW-tih-dee Hemisus barotseensis heh-MEE-sus bare-aht-SEEN-sis Hemisus marmatorus heh-MEE-sus mar-mah-TOR-us Hemisus sudanensis heh-MEE-sus soo-dan-EN-sis Hyalinobatrachium valerioi high-ah-LIN-oh-bah-TRAK-ee-um vah-LAIR-ree-oh-eye Hyla leucophyllata HIGH-lah loo-ko-fye-LAT-ta Hylidae HIGH-lih-dee Hynobiidae high-no-BEE-eye-dee Hynobius retardatus high-NO-bee-us ree-tar-DAT-tus Hyperoliidae high-per-OLE-lee-eye-dee Hyperolius marginatus high-per-OLE-lee-us mar-jin-AT-tus Hyperolius marmoratus high-per-OLE-lee-us mar-more-AT-tus Hyperolius viridiflavus high-per-OLE-lee-us vir-rid-ih-FLA-vus Ichthyophiidae ik-thee-oh-FYE-eye-dee Ichthyophis glutinosus ik-thee-OH-fis gloo-tin-OH-sus Kaloula pulchra kah-LOW-oo-la PULL-kra Kassina senegalensis kah-see-na sen-ee-gall-EN-sis Leiopelma hamiltoni lay-oh-PEL-ma ham-il-TO-nye Leiopelma pakeka lay-oh-PEL-ma pa-KEY-ka Leiopelmatidae lay-oh-pel-MAH-tih-dee Lepidobatrachus laevis lep-ee-doh-bah-TRAK-us lay-EH-vis Leptobrachium banae lep-toh-BRAK-ee-um BAN-nee Leptodactylidae lep-toh-dak-TIL-ih-dee Leptodactylus pentadactylus lep-toh-dak-TIL-us pen-ta-DAK- til-us Pronunciation Guide for Scientific Names xi

Limnodynastidae lim-no-dye-NAS-tih-dee Lithodytes lineatus lih-thoh-DYE-teez lin-ee-AT-tus Litoria caerulea lih-TOR-ree-uh seh-RU-lee-uh Mantidactylus liber man-ti-DAK-til-us LEE-ber Megophryidae me-go-FRY-ih-dee Megophrys montana me-go-FRIS mon-TAN-ah Micrixalus phyllophilus my-krik-SAL-us fye-LO-fil-us Microbatrachella capensis my-kro-bah-trak-ELL-la cap-PEN-sis Microhyla karunaratnei my-kro-HIGH-la kare-roo-nah-RAT- nee-eye Microhylidae my-kro-HIGH-lih-dee Myobatrachidae my-oh-bat-TRAK-ih-dee Nasikabatrachidae nas-SIK-ka-bat-TRAK-ih-dee Nasikabatrachus sahyadrensis nas-SIK-ka-bat-TRAK-us sa- HIGH-ah-dren-sis Necturus maculosus nek-TOO-rus mak-u-LOH-sus Neobatrachus pictus nee-oh-bat-TRAK-us PIK-tus Notaden melanoscaphus NO-tah-den mel-an-oh-SKAF-us Nyctixalus pictus nik-TIK-sal-us PIK-tus Occidozyga lima ock-sih-DOZE-ih-gah LEE-ma Onychodactylus japonicus on-ik-oh-DAK-til-us ja-PON-ih-kus Oreolalax schmidti oh-ree-oh-LA-laks SCHMIDT-eye Otophryne pyburni oh-toe-FRYN pie-BURN-eye Parhoplophryne usambarica par-HOP low-fryn u-sam-BAR-ee-ka Pelobatidae pel-low-BA-tih-dee Pelodytes punctatus pel-low-DYE-teez punk-TAH-tus Philautus papillosus fil-LAW-tus pa-pill-OH-sus Philoria pughi fil-LOW-ree-uh PYU-eye Phrynomantis bifasciatus fry-no-MAN-tis bi-FAS-see-at-tus Phyllobates terribilis fye-low-BA-teez ter-rib-BIL-iss Pipa pipa PIE-pa PIE-pa Pipidae PIE-pih-dee Plethodontidae pleth-oh-DON-tih-dee Pleurodema bufonina PLOOR-oh-dee-ma boo-fo-NEE-na Proteidae pro-TEE-ih-dee Proteus anguinus PRO-tee-us AN-gwin-us Pseudis paradoxa SOO-dis pair-ah-DOKS-sa Pseudoeurycea bellii soo-doe-yur-EE-see-ah BELL-ee-eye Rachophorus arboreus rak-OH-for-us ar-bor-EE-us Rana catesbeiana RAH-nah kat-TEEZ-bee-eye-an-uh Grzimek's Student Animal Life Resource xii

Rana temporaria RAH-nah tem-po-RARE-ee-uh Ranidae RAH-nee-dee Ranodon sibiricus RAH-no-don sib-EAR-ee-kus Rhacophoridae rak-oh-FOR-ih-dee Rhinatrematidae rye-na-tree-MA-tih-dee Rhinoderma darwinii rye-no-DER-ma dar-WIN-ee-eye Rhinodermatidae rye-no-der-MA-tih-dee Rhinophrynidae rye-no-FRY-nih-dee Rhinophrynus dorsalis rye-no-FRY-nus DOR-suh-lis Rhyacotriton cascadae rye-YA-koh-try-ton KAS-kah-dee Rhyacotritonidae rye-ya-koh-try-TON-nih-dee Salamandra salamandra sal-a-MAN-dra sal-a-MAN-dra Salamandridae sal-a-MAN-drih-dee Scaphiophryne calcarata skaf-FEE-oh-fryn kal-ka-RAT-ta Scaphiophryne gottlebei skaf-FEE-oh-fryn got-LEB-ee-eye Scaphiophrynidae skaf-fee-oh-FRYN-nih-dee Scarthyla goinorum skar-THIGH-la go-in-OR-um Scolecomorphidae skoh-lee-kom-MOR-fih-dee Scolecomorphus kirkii skoh-lee-kom-MOR-fus KIRK-ee-eye Silurana tropicalis sil-u-RA-na trop-ih-KAL-is Siren intermedia SIGH-ren in-ter-ME-dee-uh Sirenidae sigh-REN-nih-dee Sooglossidae soo-GLOSS-sih-dee Sooglossus sechellensis soo-GLOSS-sus say-shell-EN-sis Stumpffia helenae STUM-fee-uh hell-LEN-ah-ee Taudactylus eungellensis taw-DAK-til-us ee-u-jel-LEN-sis Thoropa miliaris thor-OH-pa mil-ee-AIR-iss Trichobatrachus robustus try-koh-ba-TRAK-us roh-BUS-tus Triprion petasatus TRIP-pree-on pet-TAS-sah-tus Triturus cristatus TRY-ter-us krih-STAT-us Triturus vulgaris TRY-ter-us vul-GARE-iss Tylototriton verrucosus tie-LOW-tow-try-tun ver-ruh-KOH-sus Typhlonectes compressicauda tie-flo-NEK-teez kom-press-sih- KAW-duh Uraeotyphlus oxyurus u-ray-ee-oh-TIE-flus oks-ee-YUR-us Uraeotyphylidae u-ray-ee-oh-tie-FIE-lih-dee Vibrissaphora ailaonica vie-brih-saf-FOR-uh ale-la-ON-nik-ah Xenopus laevis zee-NA-pus lay-EH-vis Pronunciation Guide for Scientific Names xiii

A Adaptable organism An organism that can adjust to various living conditions. Ambush A style of hunting in which a predator hides and waits for an unsuspecting prey animal to come to it. Amphibian A vertebrate that has moist, smooth skin; is cold- blooded, meaning the body temperature is the same as the temperature of the surroundings; and, in most instances, has a two-stage life cycle. Amplexus In frogs, a mating position in which the male clings to the female's back. Amphipods Beach fleas, water lice, and other small water- living invertebrates. Aposematic coloration Warning colors that advertise some- thing about an animal, possibly its bad-tasting, poisonous skin. Aquatic Living in the water. Arboreal Living in trees. Arthropods Insects, spiders, and other invertebrates that have jointed legs. B Balancers Structures on the sides of the head of some sala- mander larvae that support the head until the legs develop. Barbels Little bits of flesh sometimes seen dangling from the mouth or chin of animals, such as some frogs and fishes. Words to Know xv Words to Know

Bask Sunbathe; often seen in reptiles and amphibians to help warm up their bodies. Bioindicator species An organism that people can use to tell whether or not the environment is healthy. Bromeliads Plants of warm, usually tropical, forests that often grow on other plants. Their leaves typically overlap into cup shapes that can hold water. C Cannibalistic Describing animals that eat other members of their own species. Carnivorous Meat-eating. Cartilage A flexible material in an animal's body that is often associated with bones. Chorus In male frogs, a group that calls together. Chromosomes The structures in a cell that hold the DNA. Cloaca The chamber in some animals that holds waste from the kidneys and intestines, holds eggs or sperm about to be released to the outside, holds sperm entering a female's body, and is the passage through which young are born. Coniferous forest Land covered with trees that bear their seeds inside cones. Crepuscular Describing animals that are active only at dawn and at dusk. Crustaceans Water-dwelling animals that have jointed legs and a hard shell but no backbone. Cryptic coloration Colors and often patterns on an animal that help it blend into its environment. Cutaneous respiration Breathing through the skin D Deciduous forest Land covered by trees that lose their leaves during cold or dry seasons. Direct development Process by which frog eggs develop right into froglets and skip the tadpole stage. Diurnal Active during the day. DNA A chain of chemical molecules that is the instruction booklet for making a living thing; scientists can tell one species from another by comparing the DNA. Grzimek's Student Animal Life Resource xvi

E Ectothermic Describing animals whose body temperature changes when the outside air warms up or cools down. Embryo A developing animal that has not yet hatched or been born. Estivation As seen in some animals, a period of inactivity dur- ing dry spells. Explosive breeders Members of a species that breed together in a large group, usually over a very short time. F Fertilization The joining of egg and sperm to start development. Filter feeder An animal that strains water for bits of food. Foraging Searching for food. Fossorial Living underground. Froglet The life stage of a frog right after the tadpole stage. G Gill An organ for obtaining oxygen from water. Granular glands Poison glands, which in frogs are typically in noticeable bumps, often called "warts," on the back. H Herbivorous Plant-eating. Herpetologist A person who studies amphibians and reptiles. Hibernation A state of deep sleep that some animals enter in the winter to help them survive the cold weather. Hybrid Describing the young produced by parents of two dif- ferent species. IIndirect development Process by which frog eggs develop first into tadpoles and then into froglets. Infertile eggs Eggs that will never develop into young. Introduced species An animal, plant, or other species that is brought to a new location, usually by humans, either on pur- pose or by accident. Invertebrate An animal, such as an insect, spider, or earth- worm, without a backbone. Words to Know xvii

LLarva (plural, larvae) An animal in an early stage that changes form before becoming an adult. Lateral line system A row of tiny dot- or stitch-shaped organs, seen in fishes, tadpoles, and some other water-living organ- isms, that allow the animal to feel vibrations in the water. M Marsupium Found in some animals, a pouch in the adult where the young develop. Metamorphosis The changes in form that some animals make to become adult, such as tadpole to frog. Microorganisms Living things that are too small to see. Mimic To copy. Mollusk An animal with a soft, unsegmented body that may or may not have a shell. N Nocturnal Active mostly at night. Nuptial pads Seen in some frogs, thick pads that form on the forelegs, on the front feet, on the toes of the front feet, and sometimes on the chest to help the male grip onto the fe- male during mating. O Ocelli In frogs, small dots of color. Opportunistic feeder An animal that will eat just about any- thing that it can capture and swallow. Ovary The organ that makes eggs. P Palate The roof of the mouth. Paratoid glands In some frogs, a pair of enlarged poison- containing sacs found at the back of the head. Permanent body of water A body of water that is filled with water year-round. S Silt Dirt that is washed from land and collects in rivers and streams. Grzimek's Student Animal Life Resource xviii

Sperm Microscopic cells from a male that trigger eggs from a female to start development. Spicules Seen on the snout of a Mesoamerican burrowing toad, small, hard, sometimes pointy bumps. Spine Backbone; also known as the vertebral column. Spiracle In a tadpole, a tiny hole that lets water out. Sternum A bone in the middle of the chest between the ribs; breastbone. Symmetrical Describing a pattern that has two sides that are mirror images of one another. TTemporary body of water A body of water that is only filled with water for part of the year. Terrestrial Living on land. Toxin Poison. Toxicity The level of poison. Transparent See-through. Tubercles Bumps. Tympanum Eardrum, which in many frogs is visible as a round spot on the side of the head. U Utraviolet radiation A type of light that humans cannot see, but that scientists believe may be harming some frog species, especially those that live high in mountains where the radi- ation is strongest. Unken reflex Seen in some frogs and salamanders, a stiff back- bend pose that serves to warn predators that the animal is bad-tasting or poisonous. Urostyle A long, rod-shaped bone in the hip area of a frog. V Vernal pool A body of water that forms in the spring but then dries up for the rest of the year. Vertebrae The bones that make up the spinal column. Vertebrates Animals, such as birds, frogs, snakes, and mam- mals, with backbones. Vocal sac Extra flesh on the throat of most male frogs that ex- pands like a balloon when they make their calls. Words to Know xix

W Wart In frogs, a wart is a lump in the skin that contains poi- son and helps protect the frog from predators. In humans, a wart results from a virus and sometimes requires medical care. Grzimek's Student Animal Life Resource xx

AMPHIBIANS Three different types of amphibians (am-FIB-ee-uhns) live on Earth today: • Frogs are the often-slimy creatures almost everyone has seen hopping into a pond or heard calling on a spring evening. The smallest species reach less than one-half an inch (1.3 centimeters) long, while the largest can grow to more than a foot (30.5 centimeters) in length. Frogs are in the order Anura (ann-UR-uh). Toads are included in this order, too. They are simply one kind of frog. Frogs are different from other amphibians because they do not have tails when they are adults. Some frogs, called the tailed frogs, have little taillike bits of tissue, but they are not really tails. Many frogs have long and strong hind legs for hopping, but a few have short hind legs and typically get around by walking or running. • Salamanders are the four-legged, tailed animals that hik- ers or gardeners sometimes surprise when they turn over a rock or log. The smallest salamanders are less than 1.2 inches (3 centimeters) long, while the largest can grow to 4 feet 11 inches (150 centimeters) in length, or more. Sala- manders have bodies in the shape of a pipe with a tail at the rear. Most have small legs that are all about the same size. They hold their legs out to the side of the body when they are scrambling around on the ground. A few species have only two legs. The name of the salamanders' order is Caudata (kaw-DAY-tuh). Getting to Know Amphibians xxi Getting to Know Amphibians

Premaxilla MaxillaNasal Frontoparietal Exoccipital Prootic Squamosal Pterygoid Quadratojugal Ischium Ilium Sacrum Cleithrum Suprascapula I II III IV I II III IV V Prehallux Tibiale Fibulare Tibiofibula Carpals Urostyle Humerus Radioulna Presacral vertebra Metatarsal Metacarpal Femur Illustration of a frog skeleton. (Illustration by Marguette Dongvillo. Reproduced by permission.) • Caecilians (seh-SILL-ee-uhns) come in many sizes, rang- ing from just 4.5 inches long to more than 5 feet 3 inches (160 centimeters) in length, but most people have never seen them in the wild. Caecilians look rather like earth- worms, even having similar rings around their bodies, but caecilians have many things that earthworms do not, in- cluding jaws and teeth. A caecilian's tail is actually quite short, but since it blends into the rest of the body, this can be difficult to see unless the animal is flipped over. The tail in a caecilian begins at the vent, a slitlike open- ing on its underside. The caecilians are in the order Gymnophiona (jim-no-fee-OH-nuh). In all, the world holds at least 4,837 species of frogs and toads, 502 of salamanders, and 165 of caecilians. Scientists are still discovering new species, so those numbers grow larger and larger as the years pass. WHAT MAKES AN AMPHIBIAN AN AMPHIBIAN? Although frogs, salamanders, and caecilians are usually not mistaken for one another, they still share several features that make them all amphibians. Grzimek's Student Animal Life Resource xxii

Skin Some people confuse salamanders with lizards, but lizards are reptiles. An easy way to tell an amphibian from a reptile is to check for scales on the skin. Reptiles have scales, but am- phibians do not. The skin of an amphibian is at least a little bit moist, even among the rather-dry toads, and some amphibians are very slippery. Part of the slipperiness comes from the moist or wet places they live, and part of it comes from their mucus (MYOO-kus) glands. Mucus glands are little sacks that ooze a slimy substance. Amphibians also have another type of glands in their skin that ooze poison instead of mucus. Depending on the species, the poison may be weak or very strong. The poison in some of the poison frogs of South America is even powerful enough to kill a person who gets some in his or her bloodstream. In other species, just a little taste of the poison can turn a person's lips numb or cause extreme sickness. Body temperature Like fishes and reptiles, amphibians have body temperatures that become colder when the outside temperature is cold and warmer when the outside temperature is hot. Animals with a changing body temperature like this are known as ectothermic (EK-toe-thur-mik) animals. Sometimes, people call ectothermic animals "cold-blooded," but they are really only cold when the weather is also cold. Many amphibians warm themselves by sunbathing, or basking. Frogs frequently sit on shore in damp but sunny spots to bask. They may also simply swim into the warmer, upper layer of water in a pond to heat themselves up a bit. When they get too hot, they typically move to a cooler place, sometimes even going underground. This not only keeps them cooler but also helps them stay moist, which is impor- tant for their breathing. Breathing Amphibians breathe in several different ways. Like reptiles, birds, and mammals, most amphibians breathe in air through their nostrils to fill up their lungs. Caecilians have two lungs, but the left one is much smaller than the right one. This arrange- ment works well for the caecilians, which would not have room for two large lungs in their long and thin bodies. Some sala- manders have very small lungs, and a few, such as the red-backed Getting to Know Amphibians xxiii

salamander that is common in North American forests, have no lungs at all. Small or no lungs does not cause a problem for amphibians, however, because they do much of their breathing through their skin. When a person breathes in through the nose, the air trav- els into the lungs in the chest, where blood picks up the oxy- gen from the air and delivers it throughout the body. In amphibians, oxygen can pass right through their moist skin and into blood that is waiting in blood vessels just below the skin. The skin must be moist for this process to work: A dry am- phibian is a dead amphibian. Using this through-the-skin breathing, which is called cutaneous respiration (kyoo-TAIN- ee-us res-per-AY-shun), amphibians can even breathe under- water. Oxygen that is dissolved in the water can also cross the skin and enter their blood. Most amphibians go through a phase in their lives when they breathe underwater through gills, just as a fish does. Gill breath- ing is like cutaneous respiration, because dissolved oxygen in the water is picked up by blood in vessels that are in the gills. Gills are so full of blood vessels that they are typically bright red. Usually an amphibian breathes through gills only when it is young. Frogs, for instance, use gills when they are still tad- poles. A young salamander, which also has gills, is called a larva (LAR-vuh). The plural of larva is larvae (LAR-vee). Some am- phibians, however, skip the gill-breathing phase and hatch right from the egg into a lung- and/or skin-breather. Others, how- ever, keep their gills throughout their entire lives. Mudpuppies are examples of a salamander that has gills even as an adult. Since they live in the water, gills work well for them. In a few species, like the eastern newt, the animal goes through several phases: a gill-breathing larva, then a gill-less juvenile, and fi- nally a gilled adult. Hearing Besides hearing sounds like humans do, frogs and salaman- ders can hear vibrations in the ground. When the ground vi- brates, the movement travels up their front legs to the shoulder blade and then to a muscle that connects to the ear, so the am- phibian can hear it. This type of hearing can be very sensitive. Not only can amphibians hear the footsteps of an approaching predator, like a raccoon, but they can also hear something as slight as an insect digging in the soil. Grzimek's Student Animal Life Resource xxiv

WHERE AMPHIBIANS LIVE Amphibians live around the world. The only places where they do not live are in the extremely cold polar regions of the Earth, most of the islands in the ocean, and some desert areas. The three major groups of am- phibians---the frogs, the caecilians, and the salamanders---each have their own favorite climates. Caecilians stay in warm, tropical climates and nowhere else. Although frogs live just about anywhere an amphibian can live, the greatest number of species make their homes in the tropics. Salamanders, on the other hand, tend toward cooler areas. Most salamanders live north of the Equator, and many exist in areas that have all four seasons, including a cold winter. Because amphibians must keep their skin moist, they are always tied to water. That water may be a lake or river, a little puddle, a clammy spot under a log, or even a slightly damp burrow underground. In the water Most amphibians live at least part of their lives in the water. Many frogs and salaman- ders lay their eggs in the water. The frog eggs hatch into tadpoles, and the salamander eggs hatch into larvae. Both the tadpoles and the salamander larvae have gills that they use to breathe underwater. Eventually, the tadpoles turn into baby frogs, and the salamander larvae turn into young sala- manders, and both can then leave the water to live on land. Scientists do not have all of the details about caecilians, but they think the typical caecilian lays its eggs on land; the eggs hatch into young that are also called larvae and have gills; and the larvae wriggle into water. The caecilian larvae grow in the water before losing their gills and moving onto land. Those species that live on land for much of the year and only have their young in the water, often choose small pools that are only filled with water part of the year. Such pools are called temporary pools. Temporary pools, since they dry up later in the year, usually do not contain fish, which often eat amphibian eggs Getting to Know Amphibians xxv THE RISE OF THE AMPHIBIANS The oldest fossil amphibian is about 250 millions years old, but amphibians were around even before that. These animals lived when the Earth had only one large land mass that was su rrounded by ocean. That land mass was called Pangaea (pan-JEE-uh). When Pangaea began to break up about 190 million years ago, the amphibians were split up, too. The land masses continued to move around the globe and split up into the continents as they are today. While these movements were taking place, the amphibians were changing and becoming new species. Some had features that made them well- suited to life in certain temperatures or certain areas. Today, the Earth holds thousands of differ ent species.

and young. The only problem with laying eggs in a temporary pool is that the pools sometimes dry up too fast for the eggs to hatch into the tadpoles or larvae and for these to turn into land- living amphibians. When this happens, the young may die. In each major group of amphibians, some species remain in the water for their entire lives. These are known as fully aquatic (uh-KWOT-ik) animals. The word aquatic means that an organ- ism lives in the water, and the word fully means that it can al- ways live there. Some caecilians from South America live in the water. Sirens and mudpuppies are types of salamanders that live in the water as eggs, larvae, and adults. As adults, both have bod- ies that are well-designed for swimming instead of walking on land. They have strong, flattened tails to move swiftly through the water but very tiny legs. The sirens only have two small front legs and have neither back legs nor hip bones. Many frogs are fully aquatic. The clawed frogs and Surinam toads, for instance, live in just about any kind of freshwater, in- cluding swamps, slow streams, and ponds. They have very large and webbed hind feet, which make excellent paddles. One very unusual frog is the hairy frog. Adults of this species live on land most of the year, but the males will stay with the eggs underwa- ter until they hatch. During this time, the male develops "hairs" all over the sides of its body. The hairs are actually thin fringes made of skin. This gives him more skin area and makes it easier for him to breathe. With his "hairs," he is able to stay underwa- ter for days with his eggs without ever coming up for air. Tadpoles, aquatic larvae, and some aquatic adult amphibians have lateral (LAT-eh-rul) line systems. Fishes have lateral line systems, too. The lateral line system looks like a row of stitch- like marks or dots that runs down each side of the body. In- side each mark or dot are tiny hairs that sway one way or the other with the movements of the water. When another animal swims past or enters the water nearby, the hairs lean and send a message to the amphibian's brain that it is not alone in the water. This helps amphibians to escape predators or, if they eat insects or other water-living prey, to find the next meal. Along the ground Many adult frogs and salamanders live on land and along the ground. Since they have to keep their skin moist, they often huddle under a rotting log, inside a crack in a rock, in piles of dead leaves, under the low-lying leaves of plants, or in some Grzimek's Student Animal Life Resource xxvi

other damp place. Once in a while, a caecilian is also found snuggled between a leaf and stem in a low plant. In many cases, amphibians only move about on the ground during or after a heavy rain. Some, like the American toads, can survive under a bit drier conditions than other amphibians and hop or walk around the forest floor even on warm and dry summer days. Above the ground Some frogs and salamanders will venture into the trees. An- imals that spend part of their lives off the ground and in plants or trees are known as arboreal (ar-BOR-ee-ul) animals. Among the salamanders, only some lungless salamanders are arboreal. One, which is known as the arboreal salamander, may crawl under tree bark or climb into tree holes to escape hot and dry weather. Many more frogs than salamanders are arboreal. Hun- dreds of these are called treefrogs and have sticky, wide pads on the tips of their toes to help them scramble up plants and trees. Some of the arboreal frogs live in humid forests that are Getting to Know Amphibians xxvii Life cycle of a salamander (Ambystoma opacum) and frog (Rana temporaria); a. and b.--- adults; c.---eggs laid in water; d.--- ---terrestrial salamander eggs laid in a moist area on land; e, f, g, h---larval stage; i and j---juvenile stage. (Illustration by Jacqueline Mahannah. Reproduced by permission.) Eggs Adults Larvae a b e g f h c d i j Salamanders Frogs/Toads

moist enough for them to sit out on leaves most of the time. Others need more moisture and find it in bromeliads (broh-MEE- lee-ads), which are plants that often grow on the sides of trees and have tube-shaped leaves that catch rainwater. There, the frogs find tiny pools where they can dip their bodies or float. Under the soil Since amphibians need to keep their skin moist, many of them find dampness under the soil. Animals that live underground are called fossorial (faw-SOR-ee-ul) animals. Most of the cae- cilians remain underground, only coming up to the surface once in a while to feed. They typically have tiny eyes and are nearly blind, although they can tell light from dark. They make their own burrows, digging headfirst into moist soil. Among the salamanders, the best-known burrowers are the mole salaman- ders. These salamanders, which live through much of North America, usually do not make their own burrows, instead bor- rowing them from mice and other small rodents. They stay in- side these underground hideaways until rains wet the ground. At that time, they climb out and look for food to eat. Many of the mole salamanders, such as the blue-spotted salamander, also may live under rotting logs. The larger spotted salamander sometimes hides under rocks or deep in a damp well. Numerous frog species, including the spadefoot toads, live underground for much of their lives. They, like many other burrowing frogs, have a hard bump that looks like the edge of a shovel blade on each of their digging feet. Some burrowing frogs do not have hard bumps on their feet. They do, however, have powerful digging legs and usually wide feet to move away the soil as they burrow. HOW DO AMPHIBIANS MOVE? Since amphibians may have four legs, two legs, or no legs at all, and they may spend most of their time on the ground, in the water, or in trees, they move in many different ways. Some walk or run; some hop or leap; some swim; some burrow; and some even glide through the air. Walking and running The land-living, or terrestrial (te-REH-stree-uhl), salamanders travel from one place to another by walking or running. They do this with their bodies very close to the ground and their up- Grzimek's Student Animal Life Resource xxviii

per legs held out from the body in the same position that a per- son takes when starting to do a push-up. 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. These bones give the frog's leaps added boost. 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. The aquatic caecilians swim much as snakes do, waving their bodies back and forth in "s" patterns to slither-swim through the water. 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 Getting to Know Amphibians xxix

the soil. 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. WHAT DO AMPHIBIANS EAT? 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. 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 19.7 inches (500 centimeters) in length, sometimes eat other animals, such as small lizards and baby mice that crawl on top of the leaf-covered ground where the caecilians live. 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. Grzimek's Student Animal Life Resource xxx

Plant eaters Tadpoles are usually herbivorous (urh-BIH-vor-us), which means that they eat plants. Many have beaklike mouths that scrape algae (AL-jee) and other scum from rocks and under- water plants. Some, like the tadpoles of spadefoot toads, will eat invertebrates in addition to plants. AMPHIBIANS AS PREY A wide variety of animals attack and eat amphibians. Birds, snakes, raccoons and other mammals, fishes, and other am- phibians are their predators. Even insects, like diving beetles, can kill a tadpole. For most amphibians, the best defense against their predators is to remain still and let their camouflage colors help them stay out of sight. Frogs, in particular, are often the same color as their surroundings. Some, like the horned frogs, Getting to Know Amphibians xxxi Amphibian behavioral and physiological defense mechanisms; a. Marine toad (Bufo marinus) inflates its lungs and enlarges; b. Two-lined salamander (Eurycea bislineata) displays tail autotomy (tail is able to detach); c. Eleutherodactylus curtipes feigns death; d. Echinotriton andersoni protrudes its ribs; e. Bombina frog displays unken reflex. (Illustration by Jacqueline Mahannah. Reproduced by permission.) a b c d e

have large and pointy heads that look much like dead leaves. 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. REPRODUCTION In all three groups of amphibians, mating involves both males and females. 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. This mixing is called fertilization (FUR-tih-lih-ZAY-shun). 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. In the caecilians, the male adds his fluid to the eggs while they are still inside the female's body. 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. In some species, the adults lay the eggs on land but near water; the eggs hatch into tadpoles or larvae that squirm into the water or scramble onto the parent's back for a ride to the water. A number of species have young that never enter the water. In many of these amphibians, Grzimek's Student Animal Life Resource xxxii

the eggs skip the tadpole or larvae stage and hatch right into miniature adults. ACTIVITY PERIODS Amphibians often have certain times of day or times of year when they are active. 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. Getting to Know Amphibians xxxiii These aglypto frogs are engaging in a behavior known as "explosive breeding." (Photograph by Harald Sch etz. Reproduced by permission.)

Some species are diurnal (die-UR-nuhl), which means that they are active during the day. 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. AMPHIBIANS AND PEOPLE Of all the amphibians, frogs are the most familiar to people. 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- Grzimek's Student Animal Life Resource xxxiv

pounds have been made into or studied as medicines. 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. Since amphibians live on land and in the water, and often are very sensitive to changes in the environment, they are excellent alarms that can warn humans about problems, such as water or air pollution. ENDANGERED AMPHIBIANS Through the World Conservation Union, which goes by the initials IUCN, scientists keep track of how well amphibians, along with other organisms, are surviving on Earth. They separate the species into different cat- egories based on the number of individuals in the species and anything that might make them lose or gain numbers in the future. One of the categories the IUCN uses is called Data Deficient. 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: 1,165 species of frogs, 62 species of salamanders, and 111 caecilians. Many of these species are rare and/or live underground or in some other hard-to-reach location where they are difficult to study. Amphibians in danger The IUCN lists 367 species of frogs and forty-seven species of salamanders as Critically Endangered and facing an ex- tremely high risk of extinction in the wild; 623 frog species, 106 salamanders, and one caecilian are Endangered and facing a very high risk of extinction in the wild; 544 frogs, 86 sala- mander species, and three caecilians are Vulnerable and facing a high risk of extinction in the wild; and 302 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 Getting to Know Amphibians xxxv EXTRA LEGS? In 1995, a group of students at the Minnesota New Country School were outside hiking when they found frogs with odd legs, including extra feet. In all, half of the frogs they saw had some type of deformity. After this discovery, many other people began reporting other deformed frogs. Scientists immediately started tests and experiments to learn why the frogs were deformed. Today, many believe the deformities were the result of disease, pollution, and/or some of the sun's rays, called UV radiation.

Amphibian morphological defense mechanisms; a. Darwin's frog (Rhinoderma darwinii) uses camouflage and cryptic structure; b. Pseudotriton ruber and Notophthalmus viridescens display mimicry; c. Bufo americanus has poison parotid glands; d. Poison dart frog (Dendrobates pumilio) has warning coloration; e. Physalaemus nattereri has eye spots on its hind quarters. (Illustration by Jacqueline Mahannah. Reproduced by permission.) a b c d e people cut down trees for lumber or otherwise clear the land to put in farms, homes, or other buildings. Some of the other problems for amphibians come from air and water pollution, infection with a fungus that is killing amphibians around the world, and global warming. Global warming changes weather patterns, sometimes causing especially dry conditions in some places. Since frogs need to keep their skin moist, especially dry weather can be deadly to them. Saving endangered amphibians To help many of the at-risk amphibians, governments, sci- entific organizations, and other groups are protecting some of the areas where the animals live. 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- Grzimek's Student Animal Life Resource xxxvi

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. Photograph AP/World Wide Photos. Reproduced by permission. tionists are trying to raise amphibians in captivity and then releasing them into the wild with the hopes that they will sur- vive, breed, and increase the size of the natural populations. Too late to save The efforts to protect the Earth's amphibians are important, because many species have already become extinct in recent years. An extinct species is one that is no longer in existence. Getting to Know Amphibians xxxvii

This includes two species of salamanders and thirty-two species of frogs. 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. FOR MORE INFORMATION Books: Behler, John. Simon and Schuster's Guide to Reptiles and Am- phibians of the World. New York: Simon and Schuster, 1989, 1997. Clarke, Barry. Amphibian. New York: Dorling Kindersley, 1993. Florian, Douglas. Discovering Frogs. New York: Charles Scrib- ner's Sons, 1986. Halliday, Tim, and Kraig Adler, eds. The Encyclopedia of Rep- tiles and Amphibians (Smithsonian Handbooks). New York: Facts On File, 1991. Harding, J. H. Amphibians and Reptiles of the Great Lakes Re- gion. Ann Arbor: The University of Michigan Press Institu- tion Press, 1997. Lamar, William. The World's Most Spectacular Reptiles and Amphibians. Tampa, FL: World Publications, 1997. Maruska, Edward. Amphibians: Creatures of the Land and Water. New York: Franklin Watts, 1994. Miller, Sara Swan. Frogs and Toads: The Leggy Leapers. New York: Franklin Watts, 2000. O'Shea, Mark, and Tim Halliday. Smithsonian Handbooks: Reptiles and Amphibians (Smithsonian Handbooks). New York: Dorling Kindersley Publishing, 2002. Periodicals: Hogan, Dan, and Michele Hogan. "Freaky Frogs: Worldwide Something Weird Is Happening to Frogs." National Geo- graphic Explorer (March--April 2004): 10. Masibay, Kim Y. "Rainforest Frogs: Vanishing Act? Frog Pop- ulations Around the World Are Dying Off Mysteriously. Can Scientists Save Them---Before It's Too Late?" Science World (March 11, 2002): 12. Sunquist, Fiona. "The Weird World of Frogs." National Geo- graphic World (March 2002): 14. Grzimek's Student Animal Life Resource xxxviii

Walters, Mark Jerome. "Spotting the Smallest Frog: As Hopes Fade for One Species, a Tiny Frog Comes into View." Ani- mals (May--June 1997): 8. Web sites: "North American Reporting Center for Amphibian Malforma- tions." National Biological Information Infrastructure. http:// (accessed on May 15, 2005). Stoddard, Tim. "Island hoppers: Sri Lankan tree frogs end game of hide-and-seek." BU Bridge. archive/2002/10-18/frogs.htm (accessed on February 12, 2005). Trivedi, Bijal P. "Frog Fathers Provide Transport, Piggyback Style." National Geographic Today. http://news.nationalgeo- (ac- cessed on February 12, 2005). "Weird Frog Facts." Frogland. weird.html (accessed on February 12, 2005). Getting to Know Amphibians xxxix

Frogs and Toads 1 PHYSICAL CHARACTERISTICS Like mammals, birds, bony fishes, reptiles, and other amphibians, frogs are vertebrates (VER-teh-brehts). A vertebrate is an animal with a spine, or backbone. Compared with all the other vertebrates, frogs are the only ones that have this combi- nation of features: •Awide head and large mouth • Two big, bulging eyes •Ashort body with only eight or nine bones in the spine • Two extra bones in the ankle area that make their long legs even longer •Along, rod-shaped bone, called a urostyle (YUR-oh-stile) in the hip area • No tail Most of the frogs are about 1.5 to 3.0 inches (3.5 to 7.5 centimeters) long from the tip of the snout to the end of the rump. Some are much smaller. The smallest species are the Brazilian two-toed toadlet and the Cuban Iberian rain frog, which only grow to about 0.4 inches (1 centimeter) long. These compare with the unusually large Goliath frog, which can grow to 12.6 inches (32 centimeters) long and weigh 7 pounds (3.25 kilograms). 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 order CHAPTER FROGS AND TOADS Class: Amphibia Order: Anura Number of families: 28 families phylum class subclass order monotypic order suborder family

many warts. What sets them apart from other frogs---even those that are also chubby, warty, and short-legged---is something called a Bidder's organ. A Bidder's organ is a female body part that is found inside a male toad. 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. GEOGRAPHIC RANGE Frogs live in North, Central, and South America, in Europe and Asia, in Africa, and in Australia. 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 16,971 feet (5,238 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 Grzimek's Student Animal Life Resource 2

the water and make their homes on land, while others may stay in the water. 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. BEHAVIOR AND REPRODUCTION Like other amphibians, frogs can breathe through their skin, but they can only do so if the skin is moist. 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. 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. Frogs and Toads 3

Frogs often mate based on the weather. Those that live in warm, humid places may mate any time of year but usually only do so during or after a rainstorm. Frogs that make their homes in colder climates commonly wait until the temperatures warm and the spring rains have come. For species in espe- cially dry areas, the rainy season is the time for mating. The males of almost all frog species call during the mating season. They make the calls by sucking in and letting out air from the vocal sac, which is a piece of bal- loon-like skin in the throat area. Most frogs, like the spring peeper, have one vocal sac, but some species, including the wood frog, have two. The males of each species have their own calls. The calls not only attract females but sometimes tell other males to stay away and find their own mating places. In a few species, calls may not be enough, and two males may fight. Most fights are little more than wrestling matches, but in some species, like the gladiator frogs, males have sharp spines and often injure one another. In many frog species, the males call together in a group. This type of group calling is called a chorus (KOR-us). In some species, the males all call and mate over a very short time, often within a few days. 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. This mixing is called fertilization (FUR-tih-lih-ZAY- shun). Once fertilization happens, the eggs begin to develop. The tailed frogs do things a bit differently. The males have "tails," which are actually little bits of flesh they use to add their fluid to the eggs while the eggs are still inside the female's body. 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 Grzimek's Student Animal Life Resource 4 FROGS IN DANGER In the 1990s, scientists noticed that the number of frogs around the world was dropping. Some species were nearly gone, and others were already extinct. They began trying to figure out why and now believe that many things may be to blame, including air and water pollution, habitat destruction, and infection with a fungus, called chytrid (KIT-rid) fungus. They also believe that introduced species are a danger to frogs. People often add fish to streams or ponds without thinking about what will happen to the frogs that use the water, too. In many cases, fish eat frog eggs, tadpoles, and sometimes adult frogs. Just a few fish in a pond may be enough to gobble up every frog egg and tadpole for the whole season. Since most adults only live and breed for a few years, the fishes can quickly wipe out an entire frog population.

and the male leave the eggs alone to develop on their own. 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). In this amazing process, the tadpole's tail becomes shorter and shorter, tiny legs sprout, and the tadpole begins to take on the shape and color of the adults. Soon a tiny froglet, often still with a little bit of the tail left, takes its first hops. FROGS AND PEOPLE Many people greatly enjoy the sound of frogs calling on a spring or summer night. 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. CONSERVATION STATUS The World Conservation Union (IUCN) lists thirty-two species that are Extinct, which means that they are no longer in existence; one species that is Extinct in the Wild, which means that it is no longer alive except in captivity or through the aid of humans; 367 species that are Critically Endangered and facing an extremely high risk of extinction in the wild; 623 species that are Endangered and facing a very high risk of ex- tinction in the wild; 544 that are Vulnerable and facing a high risk of extinction in the wild; 302 that are Near Threatened and at risk of becoming threatened with extinction in the future; Frogs and Toads 5

and 1,165 that are Data Deficient, which means that scientists do not have enough information to make a judgment about the threat of extinction. FOR MORE INFORMATION Books: Behler, John. Simon and Schuster's Guide to Reptiles and Amphibians of the World. New York: Simon and Schuster, Inc., 1989, 1997. Clarke, Barry. Amphibian. New York: Dorling Kindersley, 1993. Florian, Douglas. Discovering Frogs. New York: Charles Scribner's Sons, 1986. Halliday, Tim, and Kraig Adler, eds. The Encyclopedia of Reptiles and Amphibians (Smithsonian Handbooks). New York: Facts On File, 1991. Harding, J. H. Amphibians and Reptiles of the Great Lakes Region. Ann Arbor: The University of Michigan Press Institution Press, 1997. Lamar, William. The World's Most Spectacular Reptiles and Amphibians. Tampa, FL: World Publications, 1997. Maruska, Edward. Amphibians: Creatures of the Land and Water. New York: Franklin Watts, 1994. Miller, Sara Swan. Frogs and Toads: The Leggy Leapers. New York: Franklin Watts, 2000. O'Shea, Mark, and Tim Halliday. Smithsonian Handbooks: Reptiles and Amphibians (Smithsonian Handbooks). New York: Dorling Kindersley Publishing, 2002. Periodicals: Hogan, Dan, and Michele Hogan. "Freaky Frogs: Worldwide Something Weird Is Happening to Frogs." National Geographic Explorer (March--April 2004: 10). Masibay, Kim Y. "Rainforest Frogs: Vanishing Act?" Science World (March 11, 2002): 12. Sunquist, Fiona. "The Weird World of Frogs." National Geographic World (March 2002): 14. Walters, Mark Jerome. "Spotting the Smallest Frog: As hopes fade for one species, a tiny frog comes into view." Animals (May--June 1997): 8. Web sites: "Anura Species Database." http://www (accessed on May 15, 2005). Morell, Virginia. "The Fragile World of Frogs." National Geographic. (ac- cessed on February 12, 2005). Grzimek's Student Animal Life Resource 6

"North American Reporting Center for Amphibian Malformations." National Biological Information Infrastructure. narcam/index.html (accessed on May 15, 2005). Stoddard, Tim. "Island hoppers: Sri Lankan tree frogs end game of hide-and-seek." BU Bridge. 10-18/frogs.htm (accessed on February 12, 2005). Trivedi, Bijal P. "Frog Fathers Provide Transport, Piggyback Style." National Geographic Today. news/2002/08/0807_020807_TVfrogs.html (accessed on February 12, 2005). Frogs and Toads 7

PHYSICAL CHARACTERISTICS New Zealand frogs are rather small creatures that have wide heads with large eyes and round pupils, but no showing eardrums. They have little or no webbing between the toes on their front or hind feet. Their four feet also have smooth soles, a feature that sets them apart from similar species living in New Zealand, which have pads or suckers on their feet. New Zealand frogs are usually brown, but some are green or reddish brown. Most have dark brown to black patterns on their legs and backs. Lines of raised bumps on their backs and other small bulges on their bellies, legs, and/or feet hold poison. 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 0.8 to 2 inches (2 to 5.1 cen- timeters) long from the tip of the head to the end of the rump. GEOGRAPHIC RANGE Although they share New Zealand with a few other species of frogs, the members of this family are the only frogs that are actually native to New Zealand. Humans introduced, or brought in, the others, which include two species of bell frogs and a brown tree frog. New Zealand frogs live on North, Maud, Great Barrier, and Stephens Islands. Conservationists in 1997 intro- duced one of the four species to Motuara Island, where it is surviving. Grzimek's Student Animal Life Resource 8 family CHAPTER NEW ZEALAND FROGS Leiopelmatidae Class: Amphibia Order: Anura Family: Leiopelmatidae Number of species: 4 species phylum class subclass order monotypic order suborder family

HABITAT Most New Zealand frogs live in damp, forested areas, where they often hide during the day under rotting logs or loose stones. Some also survive among rocks and shrubs in a misty but almost treeless part of Stephens Island. Of the four species, Hochstetter's frog prefers the wettest environment, often living near streams or other bodies of water. DIET These small frogs eat insects and other in- vertebrates (in-VER-teh-britts), which are animals without backbones, that live in their habitat. Many species of frogs capture their prey by flinging out their long tongues and using them to grasp. New Zealand frogs, on the other hand, cannot stick out their tongues. Instead, a New Zealand frog must quickly lunge at a prey animal and grab it with its mouth. BEHAVIOR AND REPRODUCTION Most people, including the native people who have lived near them for thousands of years, are completely unaware of these quiet little frogs. 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. These behaviors, com- bined with the frogs' camouflage colors and patterns, hide them from all but the most careful observers. 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 New Zealand Frogs 9 THREE RECENT EXTINCTIONS Fossils scattered throughout New Zealand show that it once was home to many frogs---all in the family Leiopelmatidae. These frogs, which have the fitting common name of New Zealand frogs, included three species that lived on the islands until 1,000 to 2,000 years ago, when they became extinct. Today, four species from this family still exist in New Zealand, but they live in very small areas compared to the land the family once called home.

forward their largest poison glands, those lo- cated in long bumps or ridges behind each eye, so that the attacker's first chomp is a mouthful of bad-tasting poison. Hochstet- ter's frog does not raise up its body as a line of defense, because its poison glands are on its belly not on its back. During mating season, most species of frogs find one another by either making loud calls, in the case of the males, or responding to those calls, as the females do. Since New Zealand frogs do not call and even lack a real voice box, scientists think that they find each other by their smells instead. The female lays five to 20 eggs, depending on the species. The developing frog is visible inside the see- through egg capsule. Hochstetter's frog lays its eggs at streamside, and the animals go through a short tadpole stage before becom- ing frogs. The other three species---Archey's, Hamilton's, and Maud Island frogs---all lay their eggs on land, but under rotting logs or in other moist spots. 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. Male Hochstetter's frogs do not care for their young. NEW ZEALAND FROGS AND PEOPLE As people have developed the land in New Zealand, these frogs have had to survive in smaller and smaller areas. Strict laws are now in place to protect the frogs and the places they live. CONSERVATION STATUS According to the World Conservation Union (IUCN), all four species in this family are in danger. The most at-risk species is Archey's frog, listed as Critically Endangered, which means that it faces an extremely high risk of extinction in the wild. They were once much more common, but when scientists counted them in 1996 and again in 2002, they found that their num- bers fell by 80 percent: four out of every five frogs had disap- Grzimek's Student Animal Life Resource 10 JURASSIC FROGS Scientists are especially interested in New Zealand frogs because they have some very primitive features, including extra backbones and muscles that are designed to move tails. Since the frogs have no tails, scientists believe the tail-wagging muscles are left over from long-extinct ancestors of these species. The only other living frogs with these features are frogs of the family Ascaphidae. The extra backbones are also seen in fossils from the first frogs to live on Earth. The fossils date back to about 150 million years ago, which means the frogs shared the planet with dinosaurs.

peared. In one population, the number of frogs went from 433 individuals to just 53. 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 1998 and have since blamed it for the de- clines of many frog species. They think an introduced species, called the Australian bell frog, brought the fungus to New Zealand and passed it on to Archey's frog in about 1998. The fungus is still a problem. When the fungus infects one of these frogs, it has trouble moving and soon becomes paralyzed. The IUCN considers Hamilton's frog to be Endangered, which means that it faces a very high risk of extinction in the wild. The remaining two species, Maud Island and Hochstet- ter's frogs, are Vulnerable and face a high risk of extinction in the wild. 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 some cases, conserva- tionists are trying to build barriers around the frogs' habitats so the predators cannot reach them. In addition, scientists are keeping a watchful eye on these three species to see if the chytrid fungus eventually affects them, too. New Zealand Frogs 11

Grzimek's Student Animal Life Resource 12 SPECIES ACCOUNTS HAMILTON'S FROG Leiopelma hamiltoni Physical characteristics: Hamilton's frog is usually light brown with a single dark stripe running along each side of the head and through the eye. 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 2.0 inches (5.1 centimeters) long from snout to rump. 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. Hamilton's frog (Leiopelma hamiltoni)

Diet: Hamilton's frog eats insects and other invertebrates. 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. 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. Hamilton's frogs and people: Humans rarely notice this quiet frog. Conservation status: The IUCN considers Hamilton's frog to be Endangered, which means that it faces a very high risk of extinction in the wild. Protection efforts are under way to protect its small home area and to help it survive into the future. New Zealand Frogs 13 One of the rarest frogs in the world, Hamilton's frog lives in a tiny area high atop Stephens Island in New Zealand. (Illustration by Brian Cressman. Reproduced by permission.)

Grzimek's Student Animal Life Resource 14 MAUD ISLAND FROG Leiopelma pakeka Physical characteristics: The Maud Island frog looks so much like Hamilton's frog that scientists thought they were the same species until 1998. 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 2.0 inches (5.1 centimeters) long from snout to rump. Females are a bit larger than males. Maud Island frog (Leiopelma pakeka)

Geographic range: It lives on a tiny scrap of land, measuring just 0.06 miles2 (0.15 kilometers2) on Maud Island in New Zealand. In 1997, conservationists gathered 300 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 980 feet (300 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. Diet: It eats insects it finds in its habitat. 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. New Zealand Frogs 15 In 1997, conservationists gathered 300 Maud Island frogs and transplanted them to Motuara Island, where they seem to be surviving well. (Illustration by Brian Cressman. Reproduced by permission.)

Maud Island frogs and people: Humans rarely see this nighttime frog. 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. Additional efforts proceed to protect and restore the frog's tiny habitat on Maud Island and to introduce the frog to a new area on Motuara Island. FOR MORE INFORMATION Books: Grigg, G., R. Shine, and H. Ehmann, eds. The Biology of Australasian Frogs and Reptiles. Chipping Norton, Australia: Surrey Beatty and Sons, 1985. Hutching, Gerard. The Natural World of New Zealand: An Illustrated Encyclopaedia of New Zealand's Natural Heritage. Auckland: Penguin, 1998. Jones, Jenny. Hamilton's Frog. Auckland: Heinemann Education, 1994. Robb, Joan. New Zealand Amphibians and Reptiles in Color. Auckland: Collins Publishers, 1980. Web sites: Barnett, Shaun. "The Trouble with Frogs." Forest and Bird Magazines. (accessed on January 20, 2005). "Frogs." Christchurch City Libraries. .nz/Childrens/FactSheets/Animals/Frogs.asp (accessed on January 28, 2005). Kingsley, Danny. "Ancient Frogs Threatened by Fungus." ABC Science Online. 537533.htm (accessed on January 20, 2005). Lehtenin, R. "Leiopelmatidae." Animal Diversity Web. http:// Leiopelmatidae.html (accessed on January 20, 2005). "Native Frog Facility to Open at Auckland Zoo." Scoop. http://www.scoop (accessed on January 20, 2005). "New Zealand Ecology: Living Fossils." TerraNature. http://www (accessed on January 20, 2005). "Welcome to the New Zealand Frog Survey (NZFS)!" University of Otago. (accessed on January 20, 2005). Grzimek's Student Animal Life Resource 16

Tailed Frogs 17 PHYSICAL CHARACTERISTICS The tailed frogs get their name from their "tails," but only the males have them and they are not really tails at all. The tiny nub of a "tail" is really a fleshy structure that the adult male uses to mate with a female. Besides the "tails," the males and females look alike. Both have wide heads and large eyes with vertical, often diamond-shaped pupils. Unlike many other frogs, they have no round patch of an eardrum showing on the sides of the head. The skin of the tailed frog's back is covered with little warts, giving it a grainy look. 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 1.2 to 2.0 inches (3 to 5 centimeters) long from the tip of the snout to the end of the rump. 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 family CHAPTER TAILED FROGS Ascaphidae Class: Amphibia Order: Anura Family: Ascaphidae Number of species: 2 species phylum class subclass order monotypic order suborder family

some of its tadpole tail left. 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. They look so much alike that scientists thought they were the same species until 2001 when they compared the frogs' DNA. 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. In other words, DNA is a chemical instruction manual for "build- ing" a 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 150 million years ago and are the oldest known frogs. GEOGRAPHIC RANGE Both species live in North America. The coastal tailed frog lives along the Pacific Ocean coastline from northern California in the United States into British Columbia in Canada, but not on Canada's Vancouver Island. The Rocky Mountain tailed frog makes its home in Idaho, western Montana, southeastern Washington, northeastern Oregon, and the most southeastern portion of British Columbia. HABITAT These frogs are found in or near clear, rocky, swift-moving streams that flow through forests. 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 Grzimek's Student Animal Life Resource 18

from the flow. 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. BEHAVIOR AND REPRODUCTION During the day, adult tailed frogs stay hidden in damp to wet spots under rocks along the streamside. 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 Tailed Frogs 19

forelegs and along their sides. These pads and bumps help the male grab and hang onto the back of a female during mating. As in other frogs, the male tailed frog must add a fluid to the female's eggs so they will develop into tadpoles and frogs. This process is called fer- tilization (FUR-tih-lih-ZAY-shun). The eggs are actually fertilized by microscopic cells called sperm that float inside the male's fluid. In most frogs, the male adds his sperm-filled fluid to the eggs as the female lays them, so the mixing of the eggs and sperm cells hap- pens outside her body. A male tailed frog, however, fertilizes the eggs differently. He swings his "tail" around, squeezes it into the hole in the female's body that she will use to lay her eggs, and releases the fluid inside her body instead of outside. The female then saves the fluid within her body until she is ready to lay her eggs the next summer. When she does lay them, her eggs are already fer- tilized. The type of fertilization that happens inside the female's body is called internal (in- TER-nuhl) fertilization. The other type of fertilization, which happens outside the body and is used by most other species of frogs, is called external (eks-TER-nuhl) fertilization. A female tailed frog can lay 35 to 100 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 Grzimek's Student Animal Life Resource 20 PIGGYBACK PADS Many male frogs, including the tailed frogs, have rough pads on the soles of their front feet that they use during mating season. In the case of the tailed frogs, the pads are black, but they can be other colors, too. Called nuptial (NUHP-shul) pads, they help the males grab hold of the female's often slippery body during mating. This grip, in which the male looks as if he is taking a piggyback ride on the female's back, is called amplexus (am-PLEK-sus). Depending on the species, the male may hold onto the female up by her forelegs, a position that is called axial (ACK-see-uhl) amplexus, while the male of other species, including the tailed frog, may hang on in front of her hind legs in a position called inguinal (ING-gwuh-nuhl) amplexus.

20 years, making them some of the longest-living frogs in the world. Through their long lives, tailed frogs remain near the spot in the stream where they were born. TAILED FROGS AND PEOPLE People are often not aware of these quiet, little nighttime frogs, and believe they are very rare. However, they are actu- ally quite plentiful in their habitat. CONSERVATION STATUS Neither species is considered to be at risk. Conservationists continue to keep watch over the frogs, however, because they must have clean and clear streams to survive. Human activity, such as logging or nearby housing development, can cause dirt and other things to wash into the frogs' streams, making the water too muddy or too polluted for the frogs to survive. Or- ganizations in Canada, in particular, have begun protecting the habitat of this frog. Tailed Frogs 21

Grzimek's Student Animal Life Resource 22 SPECIES ACCOUNT ROCKY MOUNTAIN TAILED FROG Ascaphus montanus 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. The male has a small nub of a "tail," which is actually not a real tail at all. It looks almost identical to the coastal tailed frog, except that the Rocky Mountain species has a bit more webbing between the toes of its hind feet and its tadpoles do not have the white-spotted tail tip that many of the coastal species' tadpoles do. Adults of both the Rocky Mountain tailed frog and the coastal species usually grow to 1.2 to 2.0 inches (30 to 50 millimeters) long from snout to rump. Rocky Mountain tailed frog (Ascaphus montanus)

Geographic range: This species is found in the northwestern United States, including Idaho, Montana, Oregon, and Washington and in British Columbia in Canada. 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. Tailed Frogs 23 In the wild, Rocky Mountain tailed frogs may live to be 15 to 20 years old. (Illustration by Dan Erickson. Reproduced by permission.)

Conservation status: The Rocky Mountain tailed frog is not con- sidered to be at risk. The Committee on the Status of Endangered Wildlife in Canada, however, lists it as Endangered, which means that it may soon disappear. Organizations in British Columbia have begun protecting the frog's habitat, including land in the Wycliffe Wildlife Corridor in the Kootenay region of British Columbia. FOR MORE INFORMATION Books: Corkran, Charlotte. Amphibians of Oregon, Washington, and British Co- lumbia. Auburn, WA: Lone Pine Publishing, 1996. Nussbaum, R. A., E. D. Brodie, and R. M. Storm. Amphibians and Rep- tiles of th