Guide to the Frogs of the Iquitos Region, Amazonian Peru

114 Pages·1994·7.9 MB·English

by  Lily O. Rodriguez

I Herp
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I 1994
IqQuitos Region, Amazonian Peru
ReticulatedPoison Frog Dendrohates reticiilanis i
Lily O. Rodriguez
|
AND
I
William E. Duellman
\
MaseuBJ of Comparative Zoology Llbr&r?
Harvard University
A copy of the Guide to the Frogs ofthe Iquitos Region,
AmazonianPerumaybeobtainedbywritingto:
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TheUniversityofKansas
Lawrence,Kansas 66045.USA
ThechargeforeachcopyoftheGuideis$19.95U.S.currency,
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The University of Kansas
Natural History Museum
SpecialPublication No. 22
December 1994
GUIDE TO THE FROGS
OF THE
IQUITOS REGION, AMAZONIAN PERU
By
Lily O. Rodriguez
AND
William E. Duellman
Published by
asociaciondeecologiayconservacion,
AMAZONcenterFORENVIRONMENTALEDUCATIONAND
RESEARCH,
AND
NATURALHISTORYMUSEUM,THEUNIVERSITYOFKANSAS
Lawrence, Kansas
1994
UNIVERSITYOFKANSASPUBLICATIONS,NATURALHISTORY
MUSEUM
Editor:LindaTrueb
SpecialPublicationNo.22
pp.i-ii, 1-80
Plates 1-12
PublishedDecember 1994
ISBN0-89338-047-4
^O^^^
NaturalHistory Museum
\J\^^ TheUniversityofKansas
Lawrence,Kansas 66045
^M ^'' USA
Frontcover:Dendrobatesreticulatus. PhotographbyW.W.Lamar
CoverandpublicationdesignbyLindaTrueb
©NaturalHistoryMuseum,TheUniversityofKansas
Printedonacid-free,recycledpaper
BY
UniversityofKansasPrintingService
Lawrence,Kansas
Contents
BIOGRAPHICALSKETCHES
iv
PREFACE V
INTRODUCTION
I
BiologyofFrogs 1
HowtoUsethisGuide 2
Names 4
Terminology 5
GUIDETOTHEFROGS
11
Toads (FamilyBufonidae) 11
PoisonArrowFrogs (FamilyDendrobatidae) 15
Treefrogs (FamilyHylidae) 20
Egg-broodingFrogs{GenusHemiphractus) 21
Treefrogs(Genus//y/a) 22
Broad-headedTreefrogs(GeneraOsteocephalusand 39
Phrynohyas)
LeafFrogs{GentxdiAgalychnisandPhyllomedusa) 43
Narrow-headedTreefrogs(GeneraScarthylaandScinax) 47
Hatchet-facedTreefrogs{GenusSphaenorhynchus) 50
TerrestrialFrogs (FamilyLeptodactylidae) 52
Eleutherodactylines 53
Leptodactylines 64
Narrow-mouthedFrogs (FamilyMicrohylidae) 73
AquaticFrogs (FamilyPipidae) 77
PondFrogs (FamilyRanidae) 78
SELECTEDREFERENCES 79
PLATES 1-12 Followingp. 80
MAPOFIQUITOS REGION InsideBackCover
Biographical Sketches
TheauthorsatExploramaLodge,Peru,April 1993.
PhotographbyCharlesOlmstead.
LilyO.RodriguezreceivedherdoctoraldegreeinecologyattheUniver-
sity ofParis in 1991. Since 1979, she has conducted field research in
Amazonian Peru on the taxonomy, ecology, and life histories offrogs.
SheisaResearchAssociateoftheMuseodeHistoriaNatural,Universidad
NacionalMayordeSanMarcosinLima,Peru,andaFieldAssociateof
theAmericanMuseumofNaturalHistory,NewYork. Address: Museo
deHistoriaNatural,Apartado 14-0434,Lima 14,Peru.
WilliamE.DuellmanreceivedhisPh.D.fromTheUniversityofMichi-
ganin 1956. Since 1959,hehasbeenassociatedwithTheUniversityof
Kansas,whereheisCuratorofHerpetologyintheNaturalHistoryMu-
seumandProfessorintheDepartmentofSystematicsandEcology. Most
ofhismorethan270publicationsdealwiththesystematics,lifehistory,
andecologyoffrogsintropicalAmerica. Address:NaturalHistoryMu-
seum,UniversityofKansas,Lawrence,Kansas66045-2454,USA.
Preface
Within the past two decades devastation oftheAmazon rainforest has
attracted the attention ofnotonly biologists and conservationists, butalso
thegeneralpublic. Biologistshaveendeavoredtoinventory thebiota,and
conservationists have struggled to preserve large tracts of the rainforest.
Amateurnaturalistsandlaypersonsfromallwalksoflifehaveventuredto
theAmazon Basin towitnessthe wondersofthis, the largestrainforeston
earth;asaconsequence,manyofthesepersonshavebecomeeffectiveadvo-
catesfortheconservationandstudyoftherainforestandthefantasticwealth
oflivingorganismsfoundthere.
Iquitos,Peru,isoneofthemostimportantdeparturepointsforbiological
investigations,conservationefforts,andecologicallysensitivetourism. (Other
majorpointsarePuertoMaldonado,Peru,andManausandBelem,Brazil.)
Through the combined efforts ofExploramaTours ofIquitos and Interna-
tional Expeditions, Inc., in the USA, a series of International Rainforest
Workshopswasinitiatedin 1991. Theseworkshopshavesubsequently in-
volveddozensofvolunteerinstructorsandservedasaneducationalexperi-
enceforseveralhundredworkshopparticipants. Itwaswhileservingasan
instructorinthefirstoftheseworkshopsthatthefirstauthorobservedmany
photographsoffrogstakenintheareapreviouslybyJamesH. Marlett,and
the ideaforaguidetothe frogs wasconceived. In subsequentworkshops
(1992-1994),thetwoofuscombinedoureffortstoproducethisguide.
WearegratefultoRichardRyelandRichardMills,InternationalExpedi-
tions,Inc.,forinvitingustoparticipateintheworkshops. PeterJensonand
hisstaffofExploramaToursprovideduswithcomfortableaccommodations
andefficientlogistics. Innumerableworkshopparticipantsfoundmanyfrogs
andposedcountlessquestionsthathelpedusformulatethisbook. Forpro-
vidingsomeofthephotographsusedherein,wethankLuisA.Coloma(LAC),
MichaelJ.Doolittle(MJD),WalterHodl(WH),JohnD.Lynch(JDL),James
H.Marlett(JHM),RoyW.McDiarmid(RWM),CharlesW.Myers(CWM),
AndrewYoung(AY),andespeciallyWilliamW. Lamar(WWL). Theirre-
spectivephotographsareidentifiedbytheforegoinginitialsinthecaptions;
photographs by the authors are identified by the initials LOR and WED.
Figures 1-3 were drawn byAmyLathrop, whodeservesaccoladesforthe
clarityofherillustrations. WeareespeciallygratefultoJoelSoudersofthe
IMG Corporation ofLawrence, Kansas, forhis efforts and cooperation in
providingimagesscannedfrom35-mmtransparenciesinanelectronicfor-
mat; these were composed into the color plates using PageMaker^"^ on a
Macintoshcomputer. WeareespeciallyindebtedtoLindaTrueb,whothor-
oughly edited the textand skillfully manipulated the textand illustrations
electronically, thereby achieving the high quality ofthis publication. The
entiretextwasreadbyWilliamW.LamarandErikR.Wild;wethankthem
fortheirhelpfulcomments. RichardMillsandB.AnthonyLuscombealso
offerconstructivecomments on the text. Publicationwas achievedbythe
collaborative efforts of B. Anthony Luscombe, President, Asociacion de
Ecologiay Conservacion (ECCO); Dick Mills andRichardRyel,Amazon
CenterforEnvironmentalEducationandResearch(ACEER);andPhilipS.
Humphrey,Director,NaturalHistoryMuseum,TheUniversityofKansas.
Lastly,weareindebtedtothefrogsthemselves. Theirbeautyandfasci-
nating behavior have captivated our attention for many years. Although
they do not receive the same general recognition as birds, cats, and mon-
keys,theydoplayanimportantroleintherainforestecosystem,forwhich
theydeservefarmorecreditthantheyusuallyareaccorded.
LilyO.Rodriguez
WilliamE.DuelIman
Explorama,Loreto,Peru
March1994
Introduction
About4,000speciesoffrogsarerecognizedworldwide;nearly 1,600of
these liveinSouthAmerica,wherethegreatestnumberofspeciesoccurin
theAmazonrainforestandinthehumidmontaneforestsontheslopesofthe
Andes. More than 80 species have been found at single sites in the upper
Amazon BasininEcuadorandPeru; nowhereelse inthe world isthe frog
faunamorediverse.Forcomparison,thisnumberisaboutequaltoallofthe
speciesknown intheUnitedStates andCanadaandmorethanthree times
thenumberofspeciesknownfromallofEurope.TheIquitosregionhasa
tremendousdiversityoffrogs,andrecentinvestigationshavediscoveredfive
speciesnotpreviouslyknownfromthatregion,aswellassomespeciesthat
arenewtoscience.
Hereinwepresentaccountsof112speciesoffrogsknownfromtheIquitos
region; 111 oftheseareillustratedincolor.Thisguid—eisdesignedforuseby
amateur naturalists and professional herpetologists anyone interested in
identifying adult frogs or larvae from the region and learning something
abouttheirnaturalhistory.
BIOLOGYOFFROGS
Frogsandtoadsareone(Anura)ofthethreeordersoflivingamphibians;
the others are Caudataand Gymnophiona. The Caudata includes the sala-
manders, which are most diverse in the Northern Hemisphere. Only two
generaofsalamandersenterSouthAmerica, andone speciesoccurs inthe
Iquitosregion.TheGymnophionaareelongate,limbless,wormlikeamphib-
ians.Thesepoorlyknownanimalsusuallyliveunderground(someareaquatic)
intropicalregions;severalspeciesareknownfromtheIquitosregion.Frogs
differfromotheramphibiansbybeingspecializedforjumping.Thesespe-
cializationsincludeashorteningofthebody,absenceofatail,andpresence
of long, powerful hind limbs. Like the skin ofother amphibians, that of
frogsispermeabletowater,whichinwarm,dryairwillevaporatefromthe
body and result in desiccation and death. Consequently, frogs most com-
monlyliveinplaceswhereeitherthegroundand/orairaremoistorwhere
they can replenish theirwatersupply by entering water. Replenishmentis
accomplishedbysoakingupmoisturefromthesubstrateorair,notbydrink-
ing.
Unlikemostterrestrial animals suchas salamanders, snakes,andmam-
mals,frogsdonotleavescenttrailstomarkterritoriesandidentifypotential
mates.Instead,frogs,likebirds,advertisetheirpresencebysound.Withfew
exceptions,onlymalefrogsvocalize;soundsareproducedwhenairisforced
fromthe lungsoverthevocalcordsintothemouthandintoanexpandable
vocalsacthatactsasaresonatingchamber.Inagivenregion,eachspecies
offrog has a distinctive call that is recognized by other members ofthe
1
2 RODRIGUEZANDDUELLMAN
species(andprobablybysomepredators).Somefrogsproducedifferentkinds
ofnotes;themostcommonisthecourtshipcalltoattractfemales,whereas
territorialcallsarerecognizedbyothermalesandencountercallsarepro-
ducedduringclose-rangeinteractionsbetweenmales.
MostNorthAmericansandEuropeansreceivedastereotypedconceptof
amphibianreproductioninhighschoolorcollegebiologycourses,inwhich
thelifehistory of''thefrog" waspresentedas asimple, annual, three-step
—
process (1) clumps ofeggs are laid in ponds and fertilized by the male
whilehegraspsthefemale; (2)eggshatch intoaquaticlarvae (tadpolesor
poUywogs)thatfeedonalgae,growlegs,andmetamorphose intofroglets;
and (3) youngfrogsmove ontoland, where theyfeedon insects andgrow
into adult frogs that return to the pond the following spring to repeat the
reproductiveprocess.AlthoughmostfrogsinNorthAmericaandEuropedo
follow this pattern, there are many otherdiverse andfascinating modes of
anuranreproductionanddevelopment,especiallyinthetropics.IntheIquitos
region,manyfrogsbreedthroughouttheyear,andonefemalemaydeposit
manyclutchesofeggsannually;otherspecieshaveexplosivebreedingperi-
odsfollowingheavyrains.Manytreefrogsmateinthetreesanddeposittheir
eggs onvegetationoverponds; the hatchlingtadpoles drop intothe water.
Anothergroup(Leptodactylines)deposittheireggsinfoamlikenestsonthe
surfaceofpondsoronlandadjacenttoponds;theeggsdevelopinthenest,
which reduces chances ofdesiccation and predation. Eleutherodactylines
anddendrobatidsdepositeggsonland;intheformer,thelargeeggsundergo
direct development into froglets without having an aquatic tadpole stage,
whereasindendrobatidshatchlingtadpoleswriggleontothebackofanat-
tending adult who carries the tadpoles to water. There are other kinds of
parental care that can be observed in frogs in the Iquitos region. Forex-
ample,femaleegg-broodingtreefrogscarrytheireggsontheirback where
they develop directly into froglets. In females ofthe aquatic frogs ofthe
genusPipa,eggsareimbeddedintheskinonthebackwheretheyundergo
directdevelopment intofroglets. In some dendrobatids and treefrogs, tad-
polesdevelopinwaterinarborealbromeliads,andthefemalesperiodically
returntothebromeliadstodepositunfertilizedeggsforthetadpolestoeat.
Despiteoursteadilyincreasingknowledgeaboutthenumbersandkinds
offrogsandtheirbehaviorandlifehistories,littleinformationexistsabout
manyofthespeciesintheIquitosregion.Excitingnewinformationcanbe
gainedbyanyobservantpersonwhohappenstobeintherightplaceatthe
right time when frogs are doing something never observed and recorded
before.
HOWTOUSETHISGUIDE
Thisguideisdesignedtohelpyouidentifyfrogs.Relatedfrogsaregrouped
undertheheadingsgiveninthetableofcontents; followingtheaccountof