flyflipper

MarbledMurreletTheancientmossytreesinwhichthesebirdsnestaredisappearing.
MinistryofEnvironment,LandsandParksWhyareMarbledMurreletsatriskTheMarbledMurrelet,asmall,northPacicseabird,needscoastalold-growthtreesinwhichtonest.
InBritishColumbia,andelsewhereinthemurrelet'sbreedingrange,theseancient,mossygiantsaredisappearing.
Muchofthelowandmiddle-elevationforesthasalreadybeencutandmurreletpopulationshaveprobablyalreadydeclinedfromhistoriclevels.
Asloggingspreadsintomorere-motecoastalval-leys,populationsarelikelytodeclineinpro-portiontotheamountofnest-inghabitatthatislost.
Originalforestisreplacedwithsecond-growththatmostlywillbeharvestedevery80to100years,neverallowingthetreestoreachtheage,sizeandformthatmurreletsdependonfornesting.
Fragmentedold-growthstandsandisolatedpatchesarebelievedtoprovidepoormurrelethabitatbecausenestsinthemarevulnerabletopredatorslikeravens,andtowindandotherdis-turbances.
Inrecentyears,oilspillsanddrown-ingingillnetssetforsalmonhavecausedsomemurreletdeathsontheBritishColumbiacoast.
Althoughlargenumbersofbirdswerenotinvolved,evenlowlevelsofhuman-causedmortalityareofconcernforaspecieslikethemurreletthatproducesonlyoneyoungeachyear.
Amajoroilspillcouldbecatastrophic.
HumanactivitiesareundoubtedlyhavinganadverseimpactontheMarbledMurreletinBritishColum-bia.
Becausethistrendislikelytocon-tinueforsometime,thespeciesisclearlyatrisk.
WhatistheirstatusTheMarbledMurreletlivesalongthePaciccoastofNorthAmericafromtheAleutianIslandstocentralCalifornia.
Thebulkofthepopula-tionisfoundinAlaska,withpopulationsestimatedat220000birds.
Basedonextrapolationfromafewsurveysatsea,theBritishColumbiapopulationhasbeenestimatedat45-50000birds.
About5500arepresentinWashington,15-20000inOregon,and6500inCalifornia,foratotalpopulationof280-300000.
TheMarbledMurreletisde-nedasa"MigratoryNon-gameBird"underthefederalMigra-toryBirdsConventionAct.
Thisprotectsthebirds,theirnestsandeggsfromwilfuldamagethroughoutCanadaandtheUnitedStates.
TheBritishColumbiaWildlifeAct,andvariousstatelaws,givesimilarprotection.
TheCanadianpopulation,connedentirelytoBritishColumbia,wasassignedThreatenedstatusbytheCom-mitteeontheStatusofEndangeredWildlifeinCanada()in1990.
Thisnationaldesignationisappliedtoanyspecies"thatislikelytobecomeendangeredinCanadaifthefactorsaffectingitsvulnerabilitydonotbecomereversed.
"Thisstatuswasbasedonlossofnestinghabitatandonadditionalthreatsposedbyoilspillsandshingnets.
TheMarbledMurreletisonBritishColumbia'sRedListofspeciesbeingconsideredforlegaldes-ignationasEndangeredorThreatened.
ThecombinedWashington-Oregon-CaliforniapopulationwaslistedasfederallyThreatenedbytheUnitedStatesFishandWildlifeServicein1992.
Individualstateshavealsoappliedtheirowndesignations:ThreatenedinWash-ington;SensitiveinOregon;Endan-geredinCalifornia.
ForestharvestinghasapparentlycausedseriousmurreletdeclinesinthePacicNorthweststates.
InBritishColumbia,somenestinghabitatisprotectedinnationalandprovincialparks,recreationareasandecologicalreserves.
However,thebulkofthemurreletpopulationnestsinforestshavinglittleornoprotectionfromfuturelogging.
TheBritishColumbiaWildlifeActprovidesprotectionforactivenesttrees,butnotforthesur-roundingforest.
Veryfewnestshavebeenlocatedandndingmorepromis-estobeaverydifcultandlaboriousprocess.
Sincemurreletsseldomre-useanestornesttree,theyrequireawideselectionofpotentialnestsitestomain-tainaviablepopulation.
WhatdotheylooklikeTheMarbledMurrelet(Brachy-ramphusmarmoratus)isasmall,plumpseabird,about25centimetreslong,belongingtotheaukfamilyorAlcidae.
Whenswimming,itsslenderblackbillandstubbytailareusuallytippedupward.
Initsratherdrabbreed-ingseasonplumage,thetopofthehead,backandwingsaredarkbrown,whilethethroat,chestandabdomenarebrownfleckedwithwhiteandcinna-mon,givingamottledor"marbled"appearance.
Thewinterplumageisblackaboveandwhitebelow.
Malesandfemaleshavesimilarcolouring.
InBritishColumbia,theonlyotherseabirdofsimilarsizeandshapeistheAncientMurrelet.
Insummerthisspeciesisblackandwhiteandnotlikelytobeconfusedwithitsmarbledrelative.
Inwinter,whenbothareblackandwhite,theMarbledMurreletcanbedistinguishedbyitswhitethroatandahorizontalwhitestripabovethefoldedwing.
Whenairborne,thestubbywingsofthemurreletbeatveryrapidly,TheCanadianpopulationwasdesignatedThreatenedbyin.
anditszigzagflightoverthewaterhaspromptedsomeobserverstolikenitto"anover-sizedbumblebee.
"Murreletshavesmallfeet,webbedlikethoseofaduck,thattheyusetopaddleonthewatersurface.
Whendiving,theyessentially"fly"underwater,usingtheirmuscularwingsasflippersandtheirfeetonlyforsteering.
Theydemonstrategreatspeedandagilityduringboutsofunderwatershing.
Murreletsarewelladaptedforlifeincoldnorth-Pacicwaters.
Theirdensewaterprooffeathersprovideexcellentinsulation.
ThecharacteristiccalloftheMar-bledMurreletisahigh-pitched"keer-keer,"usedforcommunica-tionbetweenindividualsandmostoftenheardarounddawnorduskasthebirdsflytoandfromtheirnests.
The"keer"callisusedtodeterminetherelativeabun-danceandprobablenestingsitesofmurreletsinforestedvalleysduringthenestingseason.
WhatmakesthemuniqueThemysteriousMarbledMurrelethasfascinatedornithologistsfordecades.
Tantalisingcluestoitsnestinghabits,suchasthediscoveryoffledglingsoreggshellfragmentsontheforestfloormilesfromthesea,accumulatedforyearswithoutanyonendinganactualnest.
Thismeagreevidencesuggestedthatdespitebeingmarvellouslyadaptedforlifeatsea,thisspeciesnestedfarinlandinancientforests.
Recentnestdiscoverieshaveconrmedthisratherradicaldeparturefromthehabitsofotherseabirds.
Butsomepuzzlesremain.
Whywouldabirdthatmustcarryshtoitschickatdawnanddusk,nest60ormorekilometresinland,whenapparentlysuit-ablesitesoccurclosertotheseaWhatevertheexplanation,suchbehav-iourmustbebenecial.
Alltheothermembersoftheaukfamilynestinburrowsindensecoloniesonsmalloffshoreislandsandareadaptedforthislifestyle.
TheMarbledMurrelet'sbrownbreedingseasonplumageandgreenish-tintedegg,bothunusualamongalcids,appeartobeadaptationsfornestingintheforest.
Thiscrypticcolouringprovidescamouflageandreducestheriskofbeingspottedbypredators.
However,forestfragmentationcanopentheforesttonewpredatorsthataremoreadeptatdetectingmurreletsandtheireggs.
Thisspeciesdiffersfrommostfor-est-nestingbirdsinthatitdoesnotnestincavitiesorbuildanestamongbranches.
Mostmurreletsnestonathick,mossyplatformonathicklimboronsomekindofbroaddeformityonatrunk.
Onlyoldtreesprovidethesetypesofsites,whichgreatlylimitsthemurrelet'schoicesofplacestonest.
Duetoitsdependenceonold-growthtreesfornesting,atleastfromBritishColumbiasouthward,theMarbledMurrelethasbecomeafocalpointintheconflictbetweenloggingThebulkofthemurreletpopulationnestsinforestshavinglittleprotectionfromfuturelogging.
andold-growthpreservation.
Thishasresultedinitbecomingthesubjectofmuchresearchactivitybybiologistsandnatu-ralists,andbroughtittotheattentionofforesters,loggersandthegeneralpublic.
Nat-uralists,particularlyfrominlandareas,nowplacethisbirdhighontheirlistofsought-afterspecies.
HowdotheyreproduceThenestinghabitsoftheMar-bledMurrelet,untilrecentlyoneofthegreatenigmasofornithology,arestillpoorlyknown.
Althoughthespeciesiscommonlyseenoncoastalwatersduringitsbreedingsea-son,onlyabout50nestshadbeenfoundinBritishColumbiaasof1997.
Fewerthan10ofthesewereobservedwhileinactiveuse.
AfewgroundnestshavebeenlocatedinwesternAlaskawheretreesarescrubbyorabsent,butallnestsfoundfromBritishColumbiatoCaliforniahavebeenintrees.
Nestsmaybefarinland,requiringlongflightstoandfromtheseabyadultsastheyexchangeincuba-tiondutiesorbringshtofeedtheirchick.
Themurreletnestisverysimple–ashallow,mossydepressiononalarge,horizon-taltreelimb,usuallynearthetrunk.
Nonestingmaterialsareadded.
Sofar,nestsfoundinBritishColumbiahavebeeninSitkaspruce,yellowcedar,Douglas-r,westernhemlockandmountainhemlocktreesjudgedtobe300to800yearsoldorolder.
Nesttreeswereatelevationsof170to1100metresabovesealevelanddis-tancesof10to17kmfromtheocean.
Thenestswere17to42mabovetheground.
Re-useofnestsornesttreesmayoccurinremnanthabitatwhereoptionsarelimited,butdoesnotappeartobecommonwherethebirdshaveagreaterselectionofnestsites.
Onlyoneeggislaid,butitislargeforsuchasmallbird–aboutthesizeofalargechickenegg!
Theeggispalegreenish-yelloworgreen-ish-buffwithbrown,blueorgreyspotting.
MarbledMurre-letshavealengthynestingseasoninBritishColumbia.
EggsareprobablylaidfromearlyMaytolateJuneandmostnestlingsareraisedfromearlyJunetolateJuly.
AfewpairsmaynotnishnestinguntilSeptember.
Incubation,sharedbybothadults,isesti-matedtotake30days.
Thenestlingperiodofabout28daysislongcom-paredtothatofotheralcids.
However,youngMarbledMurreletsmustbefullydevelopedandcapableofsus-tainedflightbeforetheyleavethenest.
Theirrstflightmusttakethemdirectlytoseaor,occasionally,toalakealongtheirroute.
Juvenilesaresometimesfoundontheforestfloor,wheretheyarelikelytoperishsincetheycannotreadilytakeofffromland.
Oncesafelyatsea,juvenilesusuallyjoinothermurrelets,butmustforageforthem-selves.
Theyprobablydonotbreeduntilatleasttwoorthreeyearsofage.
Mostnaturalmortalityresultsfrompredationoneggsandnestlings,andfromlossoffledglingsthatdonotmakeittothesea.
Likeotherbirdswithalowreproductiverate,survivalandlongevityofindividualsreachingadult-hoodareexpectedtobegood.
MarbledMurreletsarefrequentlyseeninpairsinallseasons,suggestingthattheymateforlife.
WhatdotheyeatMarbledMurreletsfeedmostlyonshupto8or9cminlengthandonshrimp-likecrustaceanssuchaseuphausidsandmysids.
InBritishColumbia,schoolsofjuvenilePacicsandlanceandherringareanimportantsourceoffood,particularlyinspringandsummer.
Othermarinefoodsincludesmallseaperch,rocksh,anchovy,capelinandsquid.
Juvenilesalmonaresometimescaughtbymurre-letsinlakesnearthecoast.
Thesand-lanceappearstobetheshmostoftencarriedtonestlings.
MarbledMurreletsnormallyfeedinnearshoremarinewaters,includ-ingshallowbays,channelsandfjords.
Althoughgroupsofupto100mur-reletsmaybeattractedtositeswhereshareconcentratedbytidalcurrents,theyfeedasindividuals.
Fishandcrustaceansarecaughtbyunderwaterpursuit,forwhichthemurrelet'stor-pedo-shapedbodyandflipper-likewingsarewellsuited.
Mostdivesforfoodlastlessthan30secondsandmostsh,otherthanthosecarriedtothenest,areswallowedunderwater.
AfrequentfeedingmethodistodriveaschoolofshtothesurfaceandholdRangeoftheMarbledMurreletinNorthAmericaDespitebeingmarvellouslyadaptedforlifeatsea,thisspeciesnestsfarinlandinancientforests.
ittherewithrepeatedshallowdives.
Duringthesedivesthesharepickedoffoneatatime.
The"boil-ing"actionoftheseshontheseasurfaceoftenattractsothersea-birds,particularlygullswhichareunabletodivefortheirfood.
AtanestnearSechelt,BritishColumbia,investigatorsreportedthatthechickwasfedbybothparentsbeginningshortlyafter5a.
m.
eachday.
Adultsusuallyarrivedalone,withone7to8-cmsandlanceheldcrosswaysinthebill.
Fishwerealwaysofferedtotheyoungmurreletheadrst,afterwhichtheadultmadeahastydeparture.
Sometimesbothparentsarrivedatthesametimeandonehadtowaititsturntofeedthenestling.
Onmanydaysthechickreceivedsevensh–veinthemorn-ingandtwointheevening.
WheredotheyliveTheMarbledMurreletisthemostwidelydistributedalcidinBritishColumbia.
Insummeritiscommonalongtheentirecoast.
Inwinteritoccurssparselyalongthenorthcoast,butisrelativelyabundantinshelteredwaterstothesouth,particularlyinGeorgiaStraitandadjacentfjords.
SomebirdsprobablymovesouthofBritishColumbiainwinter.
Inspring,aninfluxofmurreletshasbeennotedatseveralcoastallocations,fromearlyApriltoearlyMay.
Incontrasttomostalcids,Mar-bledMurreletspreferwaterswithin2kmoflandandareoftenfoundinchannelsandfjordsalongtheinnercoast.
TheyalsofrequentexposedcoastlineslikethewestcoastofVan-couverIsland,buttheretoo,areusu-allyclosetoshore.
Thoughwide-spread,thisspecieshasaclumpeddistributionpatternthatisdeter-minedduringallseasonsbytheavail-abilityoffood,andinsummerbybothfoodandnestinghabitat.
Importantforagingsitesincludetidalripsthroughnarrowpassages,shelvesatthemouthsofinlets,andshallowbanks.
LargefeedingconcentrationshavebeenreportedatSecheltInlet,CortesIsland,FloresIsland,BarkleySound,ClayoquotSoundandofftheWestCoastTrail.
MarbledMurreletsarebelievedtonestalongtheentireBritishColumbiacoast,usuallywithin20kmofsaltwa-ter,butpossiblymuchfurtherinland,ashappenselsewhereintheirrange.
Nestingoccursonlargecoastalislands;whethersmallforestedislandsarealsousedisnotknown.
MostnestingisintheCoastalWesternHemlockzone,butanestwasrecentlydiscoveredinthesubalpineMountainHemlockzone.
Althoughitispossible,par-ticularlyinnorthernBritishCol-umbia,thatmurreletsmightnestonthegroundinalpineorsub-alpinehabitats,thereisnoevidenceofthisatpresent.
InBritishCol-umbia,nestshavebeenfoundintheforestsofDesolationandClayoquotsounds,theCarmanah-WalbranareaofsouthwestVancouverIsland,theSecheltPeninsulaandHaidaGwaii.
Recordsofnestlingsfoundontheforestfloorandobserva-tionsofadultsflyingupvalleysandintotheforestcanopy,indi-catethatmostcoastalwatershedsareusedfornesting.
ExceptionsincludeheavilyloggedareaslikethesoutheastcoastofVancouverIsland.
MarbledMurreletsmayalsobeenseenoncoastallakes,main-lyinsummer,butoccasionallyinwinter.
Mostlakeswheretheyhavebeenobservedarewithin20kmofthesea,butsome,likeCultusandHarrisonlakes,areupto75kminland.
Thepre-ferredlakesarerearingareasforjuvenilesalmon.
WhatcanwedoTheplightoftheMarbledMurreletisnowwidelyrecognisedandthespecieshasbeenlegallydesignatedasThreatenedorEndangeredinalljurisdictionssouthofAlaska.
A1993RecoveryPlanpreparedbytheMarbledMurreletRecoveryTeamdescribestheprogramsandfundingneededtoprotectMarbledMurreletsinCanada".
.
.
byreducingthreatstotheirnestinghabitatandreducingrisksfacedbybirdsatsea.
"Butplansontheirowndonotsavewildlife.
Strongpublicsupportisneeded,particularlytosavesuitableold-growthnestinghabitatinBritishColumbia.
Murreletsprobablynestinmostlarge,unloggedareasalongtheBritish-.
MarkHobsonphoto.
MarkHobsonphotoColumbiacoast.
Keynestinghabitatsmustbelocated,describedandmappedsotheycanbeprotected.
Alandscape-levelapproachtohabi-tatconservationisclearlyrequired.
Astarthasbeenmade,withseveralco-operativeinlandandat-seasurveysinvolvingprovincialandfederalwildlifeagencies,theBCMinis-tryofForests,loggingcompanies,universitiesandconservationgroups.
TheIdentiedWildlifeManagementStrategy,Biodi-versityGuidelinesandotherhabitatconservationmeasuresbeingdevelopedundertheForestPracticesCodewillundoubtedlyprotectsomecriticalnestinghabitat.
Moreeldstudiesanddetailedsur-veysarestillrequiredtodeterminehowtointegratetheneedsofthisspecieswiththoseofotherwildlife.
Thiswillallowresourcemanagerstoestablishunhar-vestedforestnetworksthatwillaccom-modatespawningsalmon,GrizzlyBears,RooseveltElk,SpottedOwls,NorthernGoshawksandotherwildlife,aswellasMarbledMurrelets.
Conservationagenciesandthepub-licmustalsoremainalerttothethreatofoilspillsandensurethatshippingregulationsandclean-upcapabilitiesaresufcienttopreventseriousmor-talityofmurreletsandothermarinespecies.
Improvedinventoryofthesea-sonaldistributionandabundanceofmurreletsincoastalwatersisrequiredformappingofregionalsensitivitytooilspills.
Althoughsignicantmortali-tyofmurreletsduetodrowningingillnetsmayberareandlocalised,contin-uedmonitoringisneededtoensuretheproblemisproperlycontrolled.
BritishColumbiashouldbeencouragedtomaintainthecurrentbanontheuseofmonolamentnets,astheseareknowntokillseabirds.
Interestednaturalistscanprovideinvaluableassistancebyreportinganynests,orevidenceofnesting,tothenearestBCWildlifeBranchofce.
Thepublicisurgedtobecomemorefamil-iarwiththisthreatenedseabirdandtosupporttheresearch,inventoryandhabitatprotectionprogramsneededtosaveit.
.
SFUMarbledMurreletResearchProject,JohnKelsonphoto,:WildlifeBranchMinistryofEnvironment,LandsandParksPOBox9374,StnProvGovtVictoria,BritishColumbiaV8W9M4ForestRenewalBritishColumbia---.
PrintedinBritishColumbiaonrecycledpaperwithvegetableinks.
.
.
,.
SFUMarbledMurreletResearchProject,RossVennesslandphoto.
BCCFMarbledMurreletProject,TomAinsworthphoto