The coloration and relationships of Brewster's Warbler

^°'.9o^^^] GeneralNotes.

4O

^I

mental work, as a foster-parent of the Cowbird.

The

nestin question was foundinthesouthern part ofRoss Co.,Ohio,was photographed and the entiresetcollected.

— W.

F.

Henninger,

Waverly,Ohio.

The

White-throated Warblerat

Ann

Arbor,Michigan.

—

^Itooka speci

men

of the rareWhite-throated or Brewster's Warbler [Helminthophila IcHcobronchtalis)near

Ann

Arbor, Mich.,

May

18, 1902. It is an adult male, rather larger than either

H.

finus or

H.

ckrysoptera, and

much

ditterent from either in coloration.

We

have no other record for this county,and onlytwo ior

H.

J>inus, but H. chrysoptera nests here quite

commonly. — ^Norman

A.

Wood, Ann

Arbor., Mich.

The

^Coloration and Relationships of Brewster's Warbler.

—

Brew- ster's Warbler (Helminthophila leiicobronchialis) is invariably described ashavingawhitebreast

more

or less stronglywashedwithyellow; this tinge beingreducedtothe

minimum,

butstillalways present,in so-called typicalexamples.

I hope to prove that in pure plumage this bird has the under parts absolutely white, and that the slightest trace of yellow in the breast- feathers brands a specimenas intermediatebetween leticobronchialisand pinus. It iswell

known

that these extremes are connected bya perfect chain ofintermediates,andthatthefrequencyofoccurrenceoftheseinter- mediates is, if

we

count

them

all as leiicobronchialis, in inverseratioto thepurityof their coloring.

(A

fact,bythe way,which pointsstrongly to the belief that leticobronchialis is amerevariation of pinus.)

Whitish-breastedand

more

orlessgolden-winged examplesoipinusare, comparatively speaking, notrare,but the leucobronchialisendofthe grada- tion is meagerly represented by specimens

—

so meagerly, in fact, that ornithologists haveapparentlyfailed toget a clear idea ofwhatit reallyis.

Now

since this gradation isfrom a bright-yellow-breasted,green-backed,

toward

apiirc--vhite-breasted, gray-backedbird, the assumption thatit

certainlj^ stops/«.?/ short of attainment of the latter extreme would be absurd,even ifthere wereno specimensto contradictit. Thereis,how- ever, atleast one such specimen,

A

Brewster's Warbler whichIshotat Beltsville, Maryland, in

May

several years ago, andwhich is

now

inthe Smithsonian collection, has all thewhiteof the undersurface exactlyas pure and ashy, and the grayof the backas clear andas sharply defined against the yellow crown, as the best examples of H. chrysuptera.

Of

course a discrimination between pure white and very slightly tinged white can only be

made

byexperts, and itwasas expertsthat

my

father and I, bothof us artists,

examined

this specimenwith aviewtotesting this verypoint.

When

thebirdwasfresh, therewas no slightest trace of yellow in its breast, on or belowthe surface of the feathers; but this purity of coloring has been marred by a most unfortunate accident.

The

breastwastornin skinning,andgrease hasexuded ontothefeathers,

402

^{General Notes.}

\^

makinw

a patchof buff-colored stain thatwouldbemistaken for thepre- scribed yellow

wash

by any but a very close observer. This, however, might perhapsbe

removed

with turpentine.

When

^it has been proved that Brewster's Warbler does, as was tobe expected, achievea perfectlypurecoloration,it isobviousthatthedescrip- tion of true Brewster's Warbler shouldbe taken

from

a bird thuspurely colored. For, granted that it is sometimes entirely white-breasted, it

would be exactlyas rational to take as a type a strongly yellow-tinged specimen, or onefrom anypoint in the gradation toward pinus,asone with afaint,concealed yellow wash.

The

extreme

form

is of course the best representativeof thisobscure race; and theform best representing the race is, except in the narrow technical significance oftheword,

most

typical.

There is anotherpoint whichdoes not seem tohavereceived duecon- sideration in discussion about Brewster's Warbler. It is the fact that,

though the birdis

most

generally believedto beahybrid betvveen finus and chrysoptera, and the gradation between theformer and pure leuco- bronchialisiscited ascorroborativeof thistheory, thereareabsolutely no intergrades between pure lencobronc/iiali's and chrysoptera. Until such specimens arefound, the evidenceinfavorof thisviewisatbestextremely incomplete.

On

theother hand, there are several pointsthattellagainst

it,and oneof themost importantof these isthe existenceof Lawrence's Warbler. This birdisvery evidentlyahybrid betweenthe two

common

speciesalreadymentioned, and is itself extremelyrare, as suchahybrid

would

naturallybe.

Typicalspecimensarenearer ingeneral aspect1opinus thantochrysop- tera, though they have the black head-markings of the latter; and the remarkableparti-colored bird

shown

ata recentmeeting of the A. O. U.

isintermediatebetweenla-jureticeiand chrysoptera; while

none

of these shows anyaffinitywithany

plumage

ofleiicob rojichialis,whichhasalways a lightthroatanda

narrow

blackeye-line.

Itseemsscarcely possible that twospecies of Warbler should produce togethertwo perfectly distincttypes of hybrid. Ifitdepended on which species furnished the male parent, one type of offspring could only be

much commoner

than the otherifone combination of parentswere

much commoner

or

more

prolific,whichinthis caseseemsveryunlikely.

All_{this leads} onetobelievethatBrewster'sWarbler iseither adistinct species

whose

normalhabitat has yettobe discovered, but

whose

hybrids with theBlue-winged

Yellow

havefrequentlybeen found, orthatit is an independentcolor-phaseofthelatterspecies.

Thislastexplanation seems to

me

hy far the

most

plausible of all.

—

Gerald

H.

Thayer,

Monadtiock,

N.

H.

Rare Birds for Eastern

Long

Island, Nev^r York.

— Two Summer

Tanagers (Piranga erythromelas) were seen, and one taken

on

the 9th of April, 1902.

The

specimen taken was

somewhat

emaciated, but the