A Review Of The North American Subspecies Of The Great Blue Heron

2004·3.4 MB·English

by  R W Dickerman

PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
I17(3):242-250.2004.
A reviewoftheNorthAmericansubspeciesofthe GreatBlueHeron
(Ardeaherodias)
RobertW.Dickerman
MuseumofSouthwesternBiology,UniversityofNewMexico,Albuquerque,NewMexico87131,
U.S.A.,e-mail:[email protected]
—
Abstract. Geographic variationinthegreatBlueHeron{Ardeaherodias)
wascomprehensivelyreviewedbyH. C. Oberholser(1912), whorecognized
nine NorthAmerican subspecies-excludingthe so-calledGreatWhiteHeron
(A.occidentalis=A.h.occidentalis).Oberholser'srevisionprovidedtheframe-
workgenerallyfollowedinsubsequentsubspecifictreatmentsofthisspecies.
However, Payne's (1979) briefgeneral summary ofthis species' geographic
variationrejectsmostoftheseNorthAmericantaxa,recognizingasvalidonly
thenominatesubspeciesandthoseofthePacificnorthwest[A.h.fannini]and
Florida [A. h. occidentalism. My studies verify thatA. h. herodiasandA. h.
fanniniaretaxonomicallydistinct,alongwithA. h. wardiinwhichIinclude
A. h. treganzai,A. h. hyperonca, andA. h. sanctilucae. Inaddition,Iregard
A.h.lessoni,A.h.adoxa,andA.h.olgistaassynonymouswithA.h.herodias,
asallarebasedonmigrantspecimensofthisform.Inaddition,IsuspectPayne
isjustifiedasrecognizingtheCaribbeanA. h. occidentalisasvalid,basedon
itswhiteplumageandshorterheadplumes.
TheGreatBlueHeron{Ardeaherodias) holser, 1912 (Baird [Shasta Co.], Califor-
nests in North Americafrom southeastern nia);A. h. sanctilucaeThayerand Bangs,
Alaska, southern British Columbia, north- 1912 (Espiritu Santo Island, BajaCalifor-
ernAlberta,centralSaskatchewan,northern nia);A. h. lessoniWagler, 1831 (Mexico);
Manitoba,northernOntario,southernQue- A. h. adoxa Oberholser, 1912 (Curacao);
bec, New Brunswick, and Nova Scotia and A. h. olgista Oberholser, 1912 (San
southwardtotheGulfstates,southernFlor- ClementeIsland,California).Notincluded
ida; on the coastal lowlands of Mexico in Oberholser's revision was the so-called
south to Tabasco, Nayarit, and BajaCali- GreatWhiteHeron{A.occidentalis),which
fornia; and locally intheCaribbeanBasin is now widely regardedasawhite morph
(A.O.U. 1998).Therearenonestingseason ofA. herodias (e.g.,A.O.U. 1998). Inad-
specimensofGreatBlueHeronstakenbe- dition, he did include the endemic A. h.
tweentheYucatanPeninsulaofMexicoand cognatusoftheGalapagoIslands,whichis
Venezuela. Oberholser (1912) recognized theonly nestingpopulationofthisspecies
nine subspecies over this extensive area, outsideNorthAmerica.
these beingA. h. herodias L., 1758 (type Oberholser's (1912) subspecies were
locality: America [= Hudson Bay, Cana- basedondifferencesinplumagecoloration
da]);A.h.wardiRidgway,1882(Oyster[= and measurements among populations,
Estero]Bay,Florida;A.h.treganzaiCourt, which in some cases included migrants
1908 (Egg Island, GreatSaltLake, Utah); from other areas. In fact, although Ober-
A. h. fannini Chapman, 1901 (Skidegate holserwasawareofbothmigrationandoth-
[Graham Island], QueenCharlotteIslands, erformsofdispersalinthisspecies,heap-
British Columbia);A. h. hyperonca Ober- pearstohaveunderestimatedtheextentof
VOLUME117,NUMBER3
this phenomenon. For example. Bond ofA. h. wardishouldbemergedunderthe
(1935)foundthatOberholser'sA.h.adoxa oldernameofA. h.occidentalis.
fromCuracaoisbasedonaseriesofeight
specimens,allofwhicharesouthwardmi- Methods
grants ofA. h. herodias. In addition, the
adult female holotype (examined) forOb- Several caveats apply to the museum
erholser's(ibid.)A.h.olgistafromSanCle- specimensusedinthisstudy,thefirstbeing
menteIslandisalsoanexampleofthenom- thedearthofproperlylabeledandprepared
inateform,basedonitsdarkcolorationand adult nesting season skins for studies of
awingchordof433mm,eventhoughpre- geographic variation among Great Blue
viouslysynonomizedwiththelocallynest- Herons in North America. Forexample, I
ingA. h. "hyperonca" (=A. h. wardi)by foundno nesting season adultmalesfrom
Grinnell and Miller (1944) and Hellmayr Delaware, Virginia, West Virginia, and
and Conover (1948). Hellmayr and Con- Kentucky; only single males from Mary-
over(1948)alsolistedA.lessoniWagleras land, Tennessee, SouthCarolina, andAla-
asynomymofA.h.herodias,simplynoting bama; andonlytwofromNorthCarolina!
"typeinMunichMuseumexamined." Secondly, many specimens lack informa-
Oberholser's revision provided the tionongonad size, weight, andfatcondi-
framework generally followed in subse- tion,makingitdifficulttoascertainwhether
quentsubspecifictreatmentssuchasA.O. such birds are likely nesting or are mi-
U. (1931, 1957),Peters(1931),Friedmann grants.Asaresult,onemustoftenassume
etal. (1950), Palmer(1962) andHancock thatbirds are nesting on thebasis ofcol-
andElliot(1978). lection localities and dates, which can be
Morerecently,Payne(1979)hastreated complicated by (a) regional differences in
overallgeographic variationintheA. her- thetimingofbreedingactivitiesand(b)the
odiascomplex (includingA. occidentalis), migration and other forms ofdispersal in
althoughhedid soonlybriefly, generally, this species. Forexample, we know post-
andwithoutmeasurementsorreferencesto nesting southernpopulations (A. h. wardi)
subspecific names. He recognized only can be dispersing northward in the north-
three taxa in North America: the wide- easternU.S.whilenorthernbirds(A.h.her-
spreadA. h. herodias, A. h.fanniniofthe odias)areintheprocessofnesting(Dick-
north Pacific Coast, and the white-plum- erman2002).Whereascolorationandmea-
agedA.h.occidentalisoftheCaribbeanBa- surements dodistinguishthesesubspecies,
sin.MyrevisionaryworkontheGreatBlue some specimens overlap orintergrade be-
Heronbeganinanattempttoidentifythen tween the two. As aresult, these may be
recently collected Mexican specimens in eitherincludedinorexcludedfromnesting
the 1960's. Since then I have examined samples, thus introducing some degree of
most of the available adult specimens in bias into the data. In any case, Ihavear-
North American collections. My findings bitrarily set the nesting season for most
generallyagreewiththoseofPayne,except NorthAmericanpopulationsofthisspecies
thatIalsorecognizethepopulationsofpal- as April to July, subject to modification
erandlargerbirdsofsouthernandwestern based on specimens' gonadal condition,
North America as A. h. wardi. I did not weight,fatlevels,coloration,andmeasure-
examineplumagevariationinnestingpop- ments.
ulations oftheCaribbeanBasin, butthese AsecondcaveatwithGreatBlueHeron
mayconstituteavalidsubspecies{A.h.oc- specimens is that the plumage coloration
cidentalis) basedon the dominanceofthe canbe alteredby a variety offactors, in-
white morph (rare elsewhere). Ifnot rec- cludingwear,bleaching,moltstage,chem-
ognizable,thenthesepopulationsandthose icalsusedtopreserveorprotectskins,mu-
PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
seumage,andespeciallystainingduetothe feathers inadultbirds, whichrangesfrom
leakage and oxidation ofbody fat. In ad- paletodarkergray. The firstoftheseag-
dition,winter-takenspecimensinthenorth gregates consists of the moderately gray
maybeundergreaternutritional stress,so populationstowhichthenameA. h. hero-
thattheymayproducelesspowderdownto diascanbeapplied.Thesenestinsouthern
coatthefeathers.Thisinturnwouldgreatly Canada west to interior southern British
affect feather color, as the powder-down Columbia, then southward in the United
coatingproducesapalebloomthatmakes StatestoeasternWashington,NorthDako-
the plumage appear lighter. In fact, this ta, Wisconsin, Indiana, Maryland, and
sameeffectcanbeextremewhentheplum- South Carolina. The second aggregate of
ageiswashedandthepowder-downisre- palerpopulationsinthe southeastern,cen-
moved(Dickerman2004). tral,andwesternU.S.andMexicothatOb-
For my final comparisons of plumage erholser(ibid.)assignedtofoursubspecies,
colorationinGreatBlueHeronpopulations, ofwhichtheoldestnameisA.h.wardiwith
Iborrowed26adultskinstakenthroughout A. h. treganzai,A. h. hyperoncaandA. h.
North America, representing all of the sanctilucaehereconsideredsynonyms.And
mainland forms. All were clean but un- the third is the darker grayA. h.fannini,
washed specimens, taken as early in the whose range I have recommended be re-
nestingseasonandchronologicallyrecently strictedtothecoastalregionofnorthwest-
as possible. As I found no differences in ern BritishColumbiaandadjacentAlaska,
plumagecolorbetweenmalesandfemales, specifically the Queen Charlotte Islands
Icombinedthesexesforthesecomparisons. northtoPrinceWilliamSound(Dickerman
Inaddition,Imeasured214malesand 189 2004).However,asnotedearlier,theslaty-
femalesforthefollowingcharacters: wing blackcolorationoftheholotype(Chapman
ccsamsasunahunoeralosdmaalcrelysuldtssleu,citianrhsatmtga,enaeterimddhslaaeIcrtl(tnthadeehytlenrlpasgdsevts,eiheanvbs,amipysmapveetmlawxcisr)eepiouil.omnobslsseuisAenzsapfefdlssestoyc,erpc(ireuTregtralasarhbfmn,eoloegpuerenrfapsm,eor1e,ilu)edan.iramgnm,Ieidtmatntheanwtahennasoresr-d,-nye- cpnwm1oeeal9saasu0Otts1hmbiiu)ieannrrngggiehgesmoGaaelr(tnbnseDhdnteaaiorsttcr,tkmhB(reaul1ewrslu9mhmle1oiayt2cvnh)Hdheeea2dfrr0phuko0are,nt4lths)ehaep.reparoprpnbatcorlihetwcoanhudorelteamalrrcbyltaoydesdfiruosieeztwmohetn-edfo
samplet-teststodeterminethesignificances phasized in allotting pale populations to
e(iPth=er0p.l05u)maogfediofrfmereennscuersa.lIvdairdiantoitonaninaloytzhe- mfoeuarsusrubesmpeenctises.inGivtheinstshipse,ciIesa,lsoinasswehsiscehd
erage classes, because sample sizes were malesgenerallyaveragelargerthanfemales
too small forjuveniles and nestlings. Im- in nesting populations (Table 1). For ex-
matureswerenotanalyzed. ample, my overall samples reveal that
malesare4.1%largerinwindchord,3.5%
Results intaillength,6.5%inexposedculmen,and
6.5%intarsuslength(includingonly"typ-
As did Oberholser (1912), I find Great icalpopulationsofnamedforms,excluding
Blue Herons can be aggregated into three fannini because of small sample size).
distinct North American nesting popula- However,the sexesoverlapinallofthese
tions on the basis ofplumage coloration, mensuralcharacters,andt-testsoftenshow
exclusiveofthe white-phasedbirdsofthe thedifferencesare notsignificantattheP
CaribbeanBasin(A. h.occidentalis).More =0.05level.Nonetheless,itisimportantto
specifically,thisvariationinvolvesthecol- segregate the sexes when using measure-
orationoftheupper-parts, neck,andwing ments to allocate specimensto subspecies
VOLUME117,NUMBER3 245
andpopulations.Asforthemensuralchar- h. wardiandA. h. occidentalis. However,
actersthemselve—s,Ifoundthefollowing: these extremes intergrade circuitously
Wing chord. Nesting populations with throughA. h."treganzai,"A. h. "hyperon-
thelongestwingsare4.8%and5.2%great- ca"andA. h."sanctilucae"withasimilar
erthanthosewiththeshortestinmalesand patternofgeographicvariation,exceptthat
females,respectively.Meansaresmallestin A. h.occidentalishasasignificantlylonger
A. h. herodias, generally becoming pro- culmenthanall—butoneA. h. wardi(sensu
gressivelylargerthroughthepopulationsof latu) population that in eastern Mexico,
theinteriorwesternU.S.,thePacificCoast whichhasasample—sizeofonlyone!
region,andMexicotothesoutheasternU.S. Tarsus length. Nesting populations
(Table 1). However, a notable departure withthelongesttarsiare33.2%and27.3%
fromthisisthatA. h. occidentalishasthe greater than those with the smallest in
wingchordintermediate,asopposedtobe- males andfemales, respectively. Meansin
ingamongthelargestinthespecies.T-tests malesareshortestinA.h.fanniniandthen
revealthatA. h. herodiasaveragessignifi- A.h. "hyperonca"XA.h.fannini,eachof
cantly shorterin wing length than all but whichhasasignificantlyshortertarsusthan
twootherNorthAmericanpopulations,the all otherpopulations ofthe species(Table
exceptionsbeingmalesofA.h.fanniniand 1). The same is true with females, except
A.h. "treganzai.'' Bycontrast,thelatteris thatthemeansofthosetwopopulationsare
significantlyshorter-wingedthanallbutone essentially identical. Elsewhere,malesand
oftheA. h. wardipopulations, thatbeing femalesaveragesmallestinA. h. herodias
the small Texas sample. All otherpopula- andA. h."hyperonca"whichdiffersignif-
tionaldifferencesinthischaracterareinsig- icantlyfromthosewiththelongesttarsiin
nificant, with clinal intergradation being FloridaA. h. wardiandA. h. occidentalis.
smootheramon—gfemalesthanmales. However,theseextremesintergradecircui-
Tail length. Nesting populations with tously through A. h. "treganzai,"A. h.
thelongesttailsare7.7%and8.8%greater "sanctilucae" and Texas/eastern Mexican
than those with the shortest in males and populationsofA. h. wardi.
females,respectively.Meansaresmallestin
A. h. herodias and become progressively DiscussionandConclusions
and significantly larger in Texas/Florida
populationsofA.h.wardi,A.h. "hyperon- Based on these findings, I recommend
ca"XA.h.fannini,andA.h.fannini(Table recognizingthree subspeciesamongNorth
1).Allotherpopulationaldifferencesinthis AmericannestingpopulationsoftheGreat
characterareinsignificant,withrathermo- BlueHeron,excludingthewhite-plumaged
saic intergradation occurring among both A. h. occidentalisoftheCarribbeanBasin.
malesandfemales.— The first isArdea herodiasherodiasL,
Exposed culmen. Nesting populations with its moderately gray plumage and a
with the longest culmens are 29.4% and nestingrangeasoutlinedabove(seeResults
31.9% greaterthanthosewiththeshortest section).Thisthemosthighlymigratoryof
inmales andfemales,respectively.Means thesubspecies,withbirdsregularlymoving
aresmallestinA. h.fanniniandthenA. h. southward into Central America and the
"hyperonca" X A. h. fannini, each of Caribbean and as far as Belize, Panama,
which has a significantly shorter culmen Colombia,Venezuela,Curacao,andtheDo-
than all other populations of the species minican Republic (also eastward to Ber-
(Table 1).Elsewhere,malesaveragesmall- muda). In addition, lesser numbers move
estinA. h. herodias, whichdiffersignifi- elsewhere, includingnorthwardtoHudson
cantlyfromthosewiththelongestculmens Bay,northernQuebec,AnticostiIsland,and
inFlorida, Texas, andeasternMexicanA. Newfoundland(plusasavagranttoGreen-
PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
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248 PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
land),andwesttoCalifornia,Arizona,New Texas,orfromamidwinterspecimenofA.
Mexico,andColorado.A. h. adoxaandA. h. wardifromFlorida.
h. olgista ofOberholser (1912) andA. h. ContraPayne'scommentonclinalvari-
lessoniWaglerwerebasedonmigrantA.h. ation in size in the east (1979), there are
herodias. Oberholserrestrictedthetypelo- notenoughnestingcolonyorevennesting
calityofA.lessonitotheValleyofMexico. seasonspecimensyetavailabletofullydoc-
However,therearenorecordsofthespecies umentacline. As mentionedearlier,there
everhavingnestedintheValley,andPayne arenonestingseasonadultmalesfromDel-
(1979)wascorrectinjustcitingMexicoas aware, Virginia, West Virginia or Ken-
the type locality. Hellmayr and Conover tucky; only single males from Maryland,
(1948) erroneously placedA. h. olgista in Tennessee, South Carolina, and Alabama:
thesynonomyofA.h.hyperonca.However, andonlytwofromNorthCarolina.Indeed
thewingchordofthetype(433mm)isfar the best clinal variation in size is on the
too short for that population and is even westcoast,withanincreaseinculmenand
shortforA.h.herodias\Itisalsodarker,as tarsallengthfromA.h.fanniniinthenorth,
inthenominatepopulation. through an intermediate population in
Thesecondsubspeciesrecognizedhereis southernBritishColombiaandWashington,
thepaleA. h. wardi, whichincludesA. h. tothelong-billed,long- leggedA. h. "hy-
"terganzai,"A. h."hyperonca," andA. h. peronca" population of California (Dick-
"santilucae."Payne(1979)wroteinafoot- erman2004).
note(p.198)"Thetypeofwardiwastaken A.h. wardimaybeseparatedfromA.h.
on5January1881.Itisnotknownwhether herodiasasfollows:
tbhiirsdwafsroamloacalmobrreeednionrgtbhierrdnorpoapuwlianttieorni.n"g 1. Neck ofA. h. herodias darker, colder
pTvlha.aoehnrpredhguyreelerratloataiidrirsnisogaunnaessl.ol,bidmmTaroeehdnuaaedbss(tuOutibrtrtyeeehphrammeatheesonniolttltfsowssenAartg.sthe1harhf9an.1rnt2aaoiw,nmlaa,ynTrtcayhdmubeialllolemetioeshcn1Aea).,alr, 2. bmon"deCeovihhciraeiknessn,atodcenfexauaotAntneu.dndsos"hufi.bsveugmwelarailoraadldwyn-yidv.vte.eshnd.xetatrreaek"lnyewdera,snreimntctehokAru.s,ts"hthfer.aipiphaaneerltreeli-ayrs
mGosonrauleltyaehteeAaBx.sattsrihe.n(mTerawsebaglricedoainn.1{)bAS.eiazhnei.dde"intsstrimelfagailareldgneezssabttia"si)ienn,dattonhhndee rowisueatdraludliciwneaitdnyhgseatnwahdhreietpawaehlb;ieertch.ehienosdftntauhntedotbhferomlaiotdw;-itnnheeAc.keyhie.s
measurements (Dickerman 1992, 2002). 3. Dorsum and wings are darkerinA. h.
OberholserdescribedA.h. "hyperonca'^as herodiasandpalerinA. h. wardi.
thecolorofA. h. herodias, butlarger.The The third subspecies recognized here is
type is from northern California and is A.h.fannini,whichdiffersfromA.h.her-
somewhatintermediatetowardsA. h.fan- odiasinbeingdarkergrayincolorandin
niniandindeedinseparablefromA.h.her- havingtheexposedculmenandtarsussig-
odiasincolor,butitislargerthanthelarg- nificantlyshorterandtaillonger(pluswing
estmaleofA.h.fanniniorofA.h.herodias in males, Dickerman 2004). A. h.fannini
(Table1).However,specimensfromcentral differs inbeing notably muchdarkergray
California in the California Academy of thanA./?.wardi(sensulatu),andinhaving
ScienceandtheMuseumofVertebrateZo- theexposedculmenandtarsussignificantly
ology labeledA. h. hyperonca are insepa- shorter.Inaddition,maleshavesignificant-
rableincolorfromatopotypeofA./?. tre- ly shorterwingsthanallA. h. wardipop-
ganzai, from early nesting season speci- ulationsexceptA./?. "treganzai"onthein-
mensfromsouthernNewMexicoandsouth teriorwestern U.S.A. h.fanniniseemsto
VOLUME117,NUMBER3 249
differfromotherGreatBlueHeronsinthat Harvard;MuseumofNaturalScience,Lou-
it perforce fishes much ofthe time from isianaStateUniversity;MuseumofSouth-
rocks ratherthan wading, as do the other westernBiology, UniversityofNewMex-
longer-legged subspecies. It appears tobe ico; Museum ofVertebrate Zoology, Uni-
largely resident within its nesting range versity of California, Berkeley; National
(contraA.O.U. 1957),withtheonlyextra- MuseumofCanada,Ottawa;NationalMu-
limital specimen being an adult taken at seum Natural History, Washington, D.C;
Wainwrighton the Arctic coastofAlaska North Carolina State Museum ofNatural
(Brock 1959). Iknow ofno specimensof Sciences, Raleigh; Peabody Museum of
AoChic.nefaotr^lteehuh.remga=frbnQaaidAunda.neepise(hen.nisrinohwCcua(ahlaptrausshdrdwilihAon)ae.tgrrtideVneha.wsIdnisoectlf"uhoaittnunrhAdevew.sdege.)arhsA.nt.fIzes"rarhlhoi.nay"mfnpBadren)s(irnobtaoiuoinnntts-dihhh lNHWMOsiaiukeultsmlusdutbamelroihiuarafolymoem,M,faHCu;ioSsCNslaheatlSnioteuacrcumnytarD,i,gaioDloenVi;Yg,ieacoHglTTti;eoeohs;rxtoTiMoamaeRrsu;ayxos,sAyaSeas&alBuUMmunCmi;roBNvkrooeoieTpfrtbheislNMresiaehatetFytmuMiCireouovalo---eldf
ewexsatmeprlne,Watshahtinpogptuolnat(iDoinckiserpmalaenr2g0r0a4y).asFoirn roifalWWasahsihnigntgotno;nUSntiavteersMiutsyeuofm,AlUansikvaerMsiut-y
A. h. wardi(sensulatu),butitiscloserto seum,Fairbanks;UniversityofKansasMu-
A.h.fanniniintheshorterexposedculmen, seum ofNatural History, Lawrence; Uni-
tarsus,andmalewingchord. versity of Nebraska State Museum, Lin-
coln;WesternFoundationVertebrateZool-
Acknowledgments ogy; Camarillo; Virginia Tech Museum
NaturalHistory,Blacksburg;ZoologyMu-
The author has measured or compared seum,UniversityofWisconsin;andthepri-
specimensofGreatBlueHeronsinover30 vatecollectionofthelateAllanR.Phillips.
museums, sometimes more than once! He He especially wishestothankthecura-
wishes to express his appreciation forthe tors ofcollections who kindly shipped to
manycourtesieshehasreceivedatthefol- New York specimens that permitted final
lowing institutions: American Museum of colorcomparisons atthe AmericanMuse-
Natural History, New York; Academy of umofNaturalHistory.Theseinclude:Cal-
Natural Sciences, Philadelphia; California iforniaAcademyofSciences,SanFrancis-
AcademyofSciences,SanFrancisco;Car- co; Carnegie Museum ofNatural History,
negie Museum of Natural History, Pitts- Pittsburgh;DenverMuseumofNaturalHis-
burgh;ColeccionOrnitologicoPhelps,Ca- tory;LosAngelesCountyMuseumofNat-
racas; Colorado StateUniversityCoopera- uralHistory;MuseumofSouthwesternBi-
tive Wildlife Research Vertebrate Collec- ology,Albuquerque;MuseumofVertebrate
tion, Fort Collins; Cornell University Zoology, Berkeley; National Museum of
MuseumofVertebrates,Ithaca;CowanVer- Natural History, Washington, D.C; Utah
tebrateMuseum,UniversityofBritishCo- MuseumofNaturalHistory,SaltLakeCity;
lumbia;DelawareMuseumofNaturalHis- and the Western Foundation ofVertebrate
rtlaoelrcytH,iiosnGt,roeUrenyni,vviDelerlsneiv;teyDr;eCnaDlvoiefnroarlMndiuasR,.eLuDoimscAkonefgyNealCteousl-;- ZaBolnoadlkoergeypo,afck[ttehhdeenaAlliMnsNLpeHocsimgAernnagcsei.loeuJss]ol.hynCrhPe.rcieHsituviben-de
James Ford Bell MuseumofNatural His- bard suffered through several revisions of
tory, University of Minnesota; James R. thismanuscriptandimproveditgreatly.
SlaterMuseumofNaturalHistory,Univer- LiteratureCited
gsHieitlsyetso;orfyMPuoufsgeeLtuosmSoAounfngde;CloemMspuasCroeautunimtvye,ofZLooNoasltouAgrnya-,l AmericNPaeonnrntOshrynliAvtmahenoirlaio,gcia5snt2s6'biprUpd.nsi,on4.th1e9d3i1t.ioCn.hecLka-nlciassttero,f
—
PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
.1957.Check-listofNorthAmericanbirds,5th Hellmayr,C.E.andH.Conover 1948.Catalogueof
edition.LordBaltimorePressInc.,Baltimore, birdsoftheAmericas,part1.No.2.Zool.Se-
Bond,JM.ar1y9l3a5.ndT,h6e91staptpu.softheGreatBlueHeronin Grinnellri,esJ,.,F&ielAd.MHu.s.MiNlaletr..Hi1s9t4.4.8:T4h3e4dpips.tributionof
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