• Robert DeCandido PhD

More Warblers, More Owls - in Manhattan No Less: Aug 10 and 11 + 13.

Updated: Feb 28

7 August 2019

Bird Notes: Saturday and Sunday morning walks continue at 7:30am and again at 9:30am. Try to make the early walk: Birds are more active then. Our second Eastern Screech-owl walk will be on Thursday evening, 15 August at Inwood Hill Park in upper Manhattan - meet at 7:30pm at the Indian Road Cafe (600 W 218th Street in 10034 - look them up). More details on each of these walks below.

Warbler migration is in full swing mode starting in August. Check previous issues of this news-letter from August 2017-2018 to see what we saw. This weekend (10-11 Aug) should be great: after Wed-Thu thunderstorms, cooler weather (with associated winds from the northwest) will come our way, bringing many warbler migrants including rare ones. We had a Cerulean Warbler well-seen on our walk this past weekend.

In this week's Historical Notes, we present: (1) 1923 note on the autumn migration of the Cerulean Warbler in our area. Back then only a mid-September push of Ceruleans was noted. But why are we getting this species in Early August now? There were fewer birders making observations in the 1920s, hence the lack of early season Cerulean observations. Also, most everyone was off looking for shorebirds in August, or in the Adirondacks on vacation. However, the research that Deborah and I have done in Central Park in the last 25 years, shows that there is also an early August wave of Ceruleans. Why the bi-modal peak of southbound Ceruleans? Are two distinct populations involved? Or do females/juveniles precede adult males or vice versa? No one knows just yet. Historical Note #2 is a 1913 discussion by J.T. Nichols who muses on the colors of warblers. As with coral reef fish or tropical butterflies, why are there so many colors - and is there any rhyme or reason to the patterns we see? It is an early discussion - we have come a long way since (but no definitive answers yet).

adult Eastern Screech-owl holding a cicada at Inwood Hill Park (Manhattan) on 6 Aug 2019 by Chris Wilhelmi (of Peru!)

Good! The Bird Walks for mid-late Summer

All Walks @ $10/person

Directions to All Meeting Locations can be found here: https://tinyurl.com/ya65n5a8

1.***Saturday, 10 Aug at 7:30am/9:30am Boathouse Cafe; 74th st/East Drive (Central Park)

2.***Sunday, 11 August at 7:30am/9:30am Boathouse Cafe; 74th st/East Dr. (Central Park)

3. Thursday, 15 August at 7:30pm - Inwood Hill Park for Eastern Screech-owls. We will be out for about 90 minutes...bring a light mosquito repellent (10% or less deet) for bare legs/arms. Bring a tiny flashlight (and if not, don't worry use your phone as a flashlight...and I will have a powerful flashlight). Meet at 7:30pm at the Indian Road Cafe (has nice bathrooms; air-con...has a bar and also restaurant). Here is a map and if you plug in your starting point, you should get directions:


Otherwise, this is the web site of the Indian Road Cafe: http://www.indianroadcafe.com/

And here is the address of the corner where we meet at 7:45pm:

600 W 218th Street in 10034

***On mornings when two walks are scheduled, you can do both walks for $10/person. So you get two for one. OR you can do either the early walk or the second walk for $10/person.

Any questions send them our way: rdcny@earthlink.net or call: 718-828-8262 (home)

CBlue Dasher Dragonfly (Male) on 4 August 2019 by Deborah Allen

The fine print: Our walks on weekends meet at 7:30am and again at 9:30am at the Boathouse Restaurant (approx. 74th street and the East Drive) through November. Please note: the Boathouse is not one of the buildings that surround the nearby Model Boat Pond - people make this mistake all the time! Our Fri/Sat/Mon walks will resume in early to mid-August.

Our home phone is 718-828-8262...and Deborah's cell is: 347-703-5554. Email is above (rdcny@earthlink.net). If you are lost and trying to get to the bird walk, call Deborah's cell phone...but remember on weekends there will be 2-3 other people calling who are also lost - please be patient. If in doubt about whether a walk will take place or not the morning of the walk: check the main landing page of this web site as well as the "Schedule" page - if the walk is cancelled, information will be posted there by 6am the day of the walk, and usually by 11pm the night before. If still confused and as a last resort, call us at home - if no one answers it means we left for the bird walk. We end all our Central Park walks (except Fridays) at the Boathouse at about noon; you can get a cup of coffee and a muffin there (around $6 total). Walks last about 3 hrs (less if hot or rainy), and you can leave at anytime - we won't be offended. If you need directions/help to your next destination, just ask someone on the walk - we are a helpful group.

Magnolia Warbler by Doug Leffler

Here is what we saw last week (brief highlights)

Saturday, 3 August (Boathouse Restaurant/Cafe at 74th st and the East Drive at 7:30am/9:30am) - We were shocked to find so many birds today, including a Cerulean Warbler (female) quickly identified by Deborah Allen ("oh my god! That's a Cerulean Warbler"). All told, we had 9 warbler species, the earliest August day that we have had this many warblers in a morning. Not only were there lots of species, there were lots of individuals: wherever we went, especially on the 7:30am walk (note to everyone - the earlier walks always produce more birds that come in closer and more often than the later walks!), we brought in 5-10 individuals, mostly Yellow Warblers (at least 25 for the morning). Second in command were Redstarts (no adult males)...and then singles of Magnolia Warbler (first of season - see above photo), Louisiana Waterthrush and two Blue-winged Warblers (first of season). We also had Red-eyed Vireos today - adults and hatch-year birds. Wood Thrushes were singing...but try as I may playing the Cuckoo call, I could bring in none. Not yet...but by mid-August, absolutely!

Deborah Allen's List of Birds for Saturday, 3 Aug: https://tinyurl.com/y2ql2kpp

Sunday, 4 August (Boathouse Restaurant/Cafe at 74th st and the East Drive at 7:30am/9:30am) - We were hoping the many birds we saw yesterday hung around for another day...but most did not. We did find the season's first Blue-grey Gnatcatcher (thank You Dr. Ryan Serio)...but there were fewer Yellow Warblers and Redstarts for sure - though we did get a nice adult male American Redstart (thank You Linda Yuan). We had six (6) warbler species in all - very good for early August...but we were hoping for a second stellar morning in a row. A good sighting was a flyover American Kestrel - young ones are wandering widely throughout the city...do look for them perched on rooftops.

Deborah Allen's List of Birds for Sunday, 4 August: https://tinyurl.com/y32p4qaj

Tuesday, 6 August (7:45pm for Eastern Screech-owls at Inwood Hill Park) - what a wonderful evening: the temperature was mild; it was not humid and we had owls. But I am getting ahead of myself here...for those who came early, such as Deborah and myself, we watched a Harbor Seal (known locally as "Sealy") on the rocks of nearby Muscota Salt Marsh (see photo below). The mammal was hauled out on the rocks, not more than 30 feet from us (and we noted the yellow rear flipper band). The seal has been here for a few weeks, and was here at this time last year as well. Also, as the tide receded, many shorebirds flew in to feed on the mud flats. I played their calls, and we had Semi-palmated Sandpipers and a few Least Sandpipers so close they were running up to our feet - and Deborah could not photograph them! However, she did get many fine images when the birds were five feet away - or a bit more.

As for the owls, the tape brought in two right away to perch almost next to each other to the delight of the 20 or so people that were with us. Who were these people? I recognized Wakako, Mark, Jackie and Victor..but everyone else was new. (With us was also Christopher Wilhelmi of Peru, who will soon relocate to London in the financial sector.)

Back to the owls: the first pair came in and were 30 feet away...the male had a Cicada in its talons. We watched them for quite a while and the photographers got their images - and we moved on. We walked the ridge trail, and came to the spot in late July where David Barrett, Deborah and me brought in a second pair. We did the same tonight, but the problem here was that the vegetation (canopy) had grown in above us, so we could hear owls all around - but only saw shadows as they flew past/over. One lucky trio, who had moved 25 feet away, watched a screech-owl at eye-level a few feet from them. We believe we had several (at least two) young ones here - the calls the owls were making were new ("interaction" calls), besides the adults trills and whinnies.

We retraced our steps coming down on the bumpy (paved/unpaved) asphalt trail that goes past the glacial potholes. We pulled in another owl via the tape that landed above us, and had more young bird calls...By this time (9:15pm), it was dark. I had promised to get everyone out by 9:30pm, so when we arrived back at the starting point (Indian Road Cafe) at 9:27pm, people were happy - for many reasons. It was a good-night.

Harbor Seal (named "Sealy" by the locals) at Inwood Hill Park (Manhattan), 6 Aug 2019 in Infra-red Black-and-white


The Cerulean Warbler (Dendroica cerulea) in Central Park, New York City [1923]. In view of the appearance of the Cerulean Warbler in the lower Hudson Valley in recent years, the following record for this species in Central Park may be of interest.

On 15 September 1923, a single female Cerulean was seen in what is commonly known as the "Ramble." The bird, in company with several Palm and Black-throated Green Warblers was observed for three or four minutes with 8x binoculars at a distance of about thirty feet. It was leisurely feeding among the smaller branches of an elm at a height of about twenty feet from the ground and did not seem to be in the least alarmed at the presence of the observer. [See also following note below.]

Apparently, there was a large southward movement of Warblers the night before, a total of eight species being recorded in less than an hour, and this bird may well have been one of the Duchess County breeders.

RUDYERD BOULTON, University of Pittsburgh, Pittsburgh, Pa.

For Central Park [1923], Mr. Griscom reported 8 Mourning Warblers (Oporonis philadelphia) between Aug. 14 and 29; Philadelphia Vireo (Vireosylva philadelphica), Sept. 16-17; a Cerulean Warbler (Dendroica cerulea), Sept. 15. seen by Mr. Boulton; a pair of Green-winged Teal (Nettizon carolinense) (1st record), Oct. 26; 2 Pine Grosbeaks (Pinicola enucleator leucura), Nov. 19, by Mr. Charles Johnson (1st record in 20 years), and a flock of Scaup Ducks flying over.

Cerulean Warbler in June 2019 by Doug Leffler

A Theoretical Analysis of the Colors of Familiar Warblers [1913] John Treadwell Nichols The writer has based this discussion on twenty-five species of Warblers with which he is familiar in life. It is the relation between color, life histories, and habitat which is treated of, a large and fascinating subject to write on, and entirely beyond the scope of the present paper to deal with exhaustively. Its aim is then to touch only on a few salient correlations or problems and perhaps clear the field for further discussion or investigation. It is hoped that readers unfamiliar with the plumages of the birds discussed will refer to some good plates or descriptions of them, but for the sake of completeness a brief review of plumages is given here. Black and White Warbler. Black and white everywhere. The crown streaked lengthwise, some slight brownish wash, more pronounced in the young, which are, however not dissimilar to the adult female. Adult male with more black on the underparts and the throat black instead of white. Golden-Winged Warbler. Gray, pale below, crown and wing patch yellow, the female with broad black throat and eye patches, separated from one another and the crown by white stripes, the black replaced by gray in the female. Tail with white markings. In the female the crown is greener than in the male, the golden patch on the wing more restricted, with a tendency to break into bars, and the upper parts washed with olive green. The young are still duller, with a heavy olive wash above and below. Blue-Winged Warbler. Above olive green, crown and underparts yellow, crissium white. A narrow black noticeable, diagnostics line from the bill through the eye. Wings gray with two white bars, Tail marked with white. Females and young are somewhat duller with greener crown and duskier eye stripe, but essentially have the same plumage. Parula Warbler. Adult male, above and wings grayish-blue, the wings with two conspicuous white bars which hold in all plumages Tail marked with white. Breast yellow, belly white Center of the back yellowish-green, a black patch before the eye A black and brown band across the breast Females and young have the eye patch and breast band reduced or wanting, the gray-blues washed with olive-green or becoming grayish olive-green. Nestlings are grayish white below. Yellow Warbler. Yellow, becoming yellowish olive-green on upper parts, wings and tail dusky, edged and marked with yellow. Adult males are brighter with the underparts streaked with chestnut red. Young are more olive above, paler below. All plumages have some yellow in the tail, ind almost all give the impression of a yellow bird. Magnolia Warbler. Wings and tail blackish. The former more or less edged with white, the latter with a broad white band near its base, which though reduced in the young is diagnostic of all plumages. Rump yellow. Below yellow, lower belly white. The adult male has the head and back gray, black patches on face, back, and upper tail coverts, and upper and lower parts heavily marked with black, and a large white patch on the wing. The female has those colors somewhat reduced, and the young have little white on the wing, are greenish above with yellow rump and grayish head, and have scarcely a trace of the black markings above or below. Cape May Warbler. Crown black in the adult male, dusky grayish in female and young. Back olive-green marked with black in the adult male, in females and young becoming grayer and losing the marking. Rump yellow in the adult male, greener and duller in females and young. Tail marked with white in adult male which is much reduced in females and young. Wing with a large white patch in adult male, with obscure whitish edgings in female and young. A chestnut area including the eye and ear-coverts on the side of the head in the adult male, obscure grayish in females and young The adult male has rich yellow underparts which color borders the chestnut on the side of the face in front running up in a narrow tongue over the eve, and extends in a broad cross area behind the chestnut almost to the nape. Females have the yellow of the male dull yellowish, fading posteriorly, and much restricted on the posterior side of the head, the young have it dull grayish, tinged with yellow. A narrow obscure streak from the bill through and behind the eve in all plumages Underparts with prolonged black striping converging forward and with a tendency to run further forward in the center than at the sides of the throat, a slight character which, however, gives a rather diagnostic appearance. The striping is grayer and reduced in females and young. The one or two females of this species which the writer has observed in the field have been readily determinable from the resemblance in character of their markings to those of the male, though in color and intensity of markings they were quite different. Black-throated Blue Warbler. Male, above wings and tail dark gray-blue. Face throat and sides black. Lower breast and belly white. Tail marked with white. A white check on the primaries near the middle of the edge of the folded wing. Female, above grayish olive green. Below whitish. The black of the male entirely absent. White check on the wing, almost always present and diagnostic, though reduced and sometimes concealed. The young resemble the adults of each sex but are duller and greener.

Black-throated Blue Warbler, September 2017 by Doug Leffler

Myrtle Warbler. Adult male black, gray and white. A yellow blotch on the crown, on either side of the breast, and on the rump. White wing bars and tall markings. A large black blotch through the eye. Heavy black streaking of the under parts coalescing to form black areas bordering the yellow on the sides of the breast. In the females and particularly in the young the black and gray are much replaced by diffuse brownish. The streaking of the underparts is much reduced and weaker. In all plumages the streaking ceases abruptly, leaving an immaculate throat, a white or whitish bib appearance quite diagnostic of the species though not tangible to describe Young fall birds have the yellow much reduced in intensity, but the yellow rump is a persistent diagnostic mark displayed when the bird is in flight. Black-throated Green Warbler. Upper parts green. Wings with white bars. Tail with white markings Face yellow. Throat and upper breast black in the male more or less yellow, without black in females and young. Sides more or less marked with black, lower breast and belly whitish. Blackburnian Warbler. Adult male in spring black and white above. Head black and orange. Throat orange. Belly white more or less suffused with orange or yellow, sides streaked with black. Wing with a large white patch. Fall, female and young birds have the white wing patch reduced to two bars. The black, and white of the upper parts more or less obscured by brownish or olive. The orange in varying degrees reduced and replaced by yellow. Chestnut-sided Warbler. Wing with two well marked yellowish bars. Tail marked with white Underparts and ear coverts white, more or less tinged with gray, especially on the latter in young and fall plumages. Upper parts yellowish-green. The adult male in spring has the crown bright yellow, rest of the upperparts heavily streaked with black, nape gray, a black stripe from nape through eye to base of bill and thence, making an acute angle, down sides of throat, where it becomes chestnut, broadens and is continued to the flanks. Adult spring females and fall males have those bright colors variously reduced. Bay-breasted Warbler. Adult spring male with top of the head, throat and sides chestnut. Middle of the belly whitish. Forehead and face black. A buffy cross patch on the side of the neck. Back grayish-buff streaked with black. Wings with two white bars, tail with white markings The young have the upperparts olive green more or less streaked with black, underparts whitish, tinged with yellow on the throat, with buffy elsewhere, and lack the bold black and chestnut colors. Females and adult fall males have a more or less intermediate plumage Wings and tail are rather constant in all plumages. Blackpoll Warbler. Adult male in spring has a solid black cap and is streaked with black and gray above. The under parts and cheeks are white, the latter separated from the throat by a narrow black streaking which extends backward from the base of the bill. Sides streaked with black. Fall males, females and young are variously greenish above more or less streaked with black, whitish below more or less washed with yellow, with or without black streaks on the sides Wing with two bars and tail with white marking in all plumages. Pine Warbler. Adult spring males are yellow green above. Yellow below turning to white on the belly, the underparts sometimes with a few streaks, the wing with white bars, the tail with white markings. The greens and yellows fade in other plum ages. Fall, female and young birds are variously duskier, some specimens being peculiarly colorless and dusky. Prairie Warbler. Above greenish, face and underparts yellow. Marks through eye, on side of throat, and on side of neck black in adult male, dusky and more or less obscure in other plumages, seldom absent. Wing bars yellowish, tail with white. Spring male with a chestnut area in the center of the back, of which there are some times traces in the female. Yellow Palm Warbler. Adults in spring are brownish olive green above, brighter on the rump. Tall with and wing without white. Line over eye eyering and underparts yellow. Streaked with chestnut below. Top of the head chestnut. Young and fall birds are duskier, the yellows paler, the streaking of the underparts grayer, the chestnut cap less pronounced or wanting. Ovenbird. Above wings and tail, uniform brownish olive, below white, streaked with black Crown bordered by two narrow dark lines, between which it is more or less orange-brown, - this color strongest and deepest in the adult spring male. A conspicuous light eye-ring. Louisiana Water-Thrush. Above wings and tail, uniform brownish olive. A white stripe over the eye. Below whitish more or less strongly buffy posteriorly, streaked with dark. The throat unmarked. Plumages similar. Northern Water-Thrush Above wings and tail, uniform olive. A buff stripe over the eye. Below lemon yellow, streaked with dark, the throat more or less streaked. Plumages similar. Maryland [Common] Yellow-Throat. Above wings and tail olive-green more or less washed with brown Outer vane of outer primary whitish. Throat yellow, fading and becoming obscured by dusky on breast and belly, brightening again on under-tail coverts. Adult male with a black mask, bordered by grayish. Hooded Warbler. Upper parts olive. Wing without bars. Outer tail feathers with white more developed than in other species, giving the appearance of white sides to the tail, when it is spread. Face and underparts yellow. In the adult male the face and forehead are yellow, surrounded by a broad black area, which comprises the crown, throat and upper breast. This hood is more or less imperfect in the young male, and more or less indicated, though not conspicuous in the female. Wilson's Warbler. The adult spring male has yellow forehead, face and under parts, green upperparts, wings and tail, and a conspicuous black cap. The black cap is more or less obscured or wanting in females and young. Canadian Warbler. Upper parts, wings and tail gray. Lores, eye-ring, and underparts yellow, a black necklace of spots across the breast. Females and young have the gray duller, yellow paler, and necklace more restricted and obscure, though seldom or never absent. American Redstart. Adult male black. Lower breast and belly white. Sides of base of tail, sides of breast, and band on wing orange. Females and young above grayish olive-green, grayer on the head, below whitish, the orange of the male replaced by yellow.

American Redstart June 2019 at Jamaica Bay by Deborah Allen

The predominating lights in the woods and thickets where Warblers are found, are greens and yellows. The predominating colors in the plumages of these birds, taken as a whole, are greens and yellows. It therefore follows that in the main their colors harmonize with their surroundings, and render them inconspicuous. However there is another obviously possible explanation of this general reproduction in color of surroundings. Most colors are chemically deteriorated by light, and evidently the action of the absorbed light would be greater than of the reflected light. Green reflects green lights and absorbs red lights (which is what makes it green); it would therefore be the most permanent and useful color in green lights. If we examine our species to see how far close relationship brings about similarity of plumage, we are struck by the fact that in the main it does not. Yellow, Blue-winged, and Wilson's Warblers, which are, perhaps the three yellowest birds, are classified at the three poles of the group. A closer view shows a strong undercurrent of phylogenic resemblances in the secondary colors well illustrated by contrasting the Blackboll and Bay-breast, which are closely allied species. In high male plumage the wings with their bars, streaked backs, and pattern of the colors are similar, but the primary colors are entirely different, making an entirely different looking bird. The Blackpoll has a black cap, the Bay-breast a chestnut one; the Blackpoll white on the side of the head, the Bay-breast black; the Blackpoll beautifully white underparts, the Bay-breast chestnut; and the area on the side of the neck where in the Blackpoll black and white streaking inconspicuously links the colors of the rest of the bird, is occupied in the Bay-breast by a diagnostic cross buff blotch. In the females of the two species, the differences are much faded, the resemblances stronger, and the young are very difficult to distinguish. The whitish wing-bars occurring in these two, and most of their even distant allies, might well have the concealing value of cross marks so ably emphasized by Thayer in arguing for the concealing coloration hypothesis. Their absence in species unrelated to these (Maryland [Common] Yellow-throat, Canadian Warbler, etc.,) indicates that they have been acquired by the distant common ancestor of the birds in which they occur, and are not a recent response to environment. In certain species they become a white blotch in the high plumaged male which adds to the display of his colors (Magnolia, Cape May, Blackburnian.) The resemblance of allied species, which we find between the Waterthrush and Ovenbird, cannot be set down as an exception to the rule just brought forward of divergence of primary specific colors in close allies; as being concealingly colored, they have no true primary specific, colors, excepting the crown patch of the Ovenbird, and furthermore resemble a Thrush in color, almost as much as they do one another. The closer resemblance of the two Water-thrushes which have different breeding ranges, however, shows where our rule breaks, namely as regards allied species occupying different ranges. Several of our species are represented in other parts of the country by allied birds which resemble them in color; as the Parula by the Sennets, and Black-throated Green by the Golden-cheeked in Texas and Mexico, and the Myrtle by the Audubon's Warbler in the West. This would be explainable on the supposition that these species are recently derived from geographic races, which almost always are very similarly colored, being only slightly different each from the common parent form. The writer further inclines to the belief that were two such species to come to occupy the same territory, the mutual advantage of dissimilarity would force them apart. In general the male Warblers are more highly colored than the females, or than the females and young. Often this high plumage is entirely different from the others (Blackpoll, Black-throated Blue.) The colors of such high plumaged birds make for conspicuousness, ready recognition and display, and it is most rational to assume that these are their biological functions. Such colors are typically blacks (Redstart, head marks of Blackpoll, Golden-wing, Magnolia, Maryland [Common] Yellow-throat, Hooded, Wilson's) grays (Black-throated Blue, Myrtle, Magnolia) and reds, as chestnut in streaks, blotches, or larger areas (Yellow, Bay-breast, Chestnut-sided, Cape May, Yellow Palm) or as making orange of yellows (Blackburnian, Redstart.) Yellows, however conspicuous they make the bird appear in a tray, of specimens or on some unwonted exposed perch, are usually inconspicuous in the field. The writer's eye on diverse occasions has had particular difficulty in picking out Parula and Blue-winged Warblers among the foliage. Ordinarily when yellows add to the beauty of the adult male's plumage, they are also possessed, somewhat modified, to be sure, by females and young. Perhaps the best illustration is the strongly yellow Blue-winged Warbler, which holds its yellow color through the different ages and sexes. We find in various species of Warblers certain small definitely shaped markings, the chief value of which is doubtless for recognition. Though sometimes subdued, they hold their character well through the duller as well as the brighter plumages of the species, which would be expected, as these are the least easily recognized from their general appearance. The markings referred to are in the main conspicuous in nature, though not overly so, and often are placed where they are hidden except when the bird is in motion or displays them by its attitude. The writer would classify as recognition marks, the face marks of Prairie Warbler and Blue-wing; the yellow in tail of the Yellow, yellow rump of the Myrtle, and yellow face of the Black-throated Green Warblers, the white basal tail band of the Magnolia Warbler, white sides of the Hooded Warbler's tail, and white check in the wing of the Black-throated Blue; the yellow eye-ring of the Canadian Warbler and cloven yellow base of the Redstart's tail. Three of our species, the Ovenbird, Northern and Louisiana Waterthrushes, have a thrush-like plumage. It is significant that these feed on the ground in the shade like the thrushes. Probably their type of plumage is particularly adapted to conceal its wearer. The bobbing tail of the Water-thrush which renders that bird conspicuous in spite of its highly concealing plumage, has in the writer's opinion a purposefully advertising function, like the incessant calling of certain concealingly colored Mammals. One of the most familiar species, the Black and White Warbler, has an almost Woodpecker-like habit of clinging to tree trunks and branches. It is interesting that this is also the species which has the black and white Woodpecker color, good evidence that there is a correlation between the color and habit, but what is the correlation? Concealing coloration will not explain it. From a man's eye view a black and white bird on a tree trunk is decidedly conspicuous, and it is not so much the white underparts, which would be seen by an insect, and which are common enough in birds, but the black and white upper parts which we are trying to explain. Recognition does not seem an adequate explanation when we consider that a similar plumage is possessed by the Woodpeckers. The plumage display is made to appear improbable by the plumage being possessed little changed in both sexes and in the young. It is of course possible to fall back upon the unsatisfactory theory that the color is determined by special, tree-trunk food, but the writer prefers the more daring one that the eye of these birds, accustomed to the contrast between dark trunks and branches and sky high lights, can handle a black and white plumage most readily, or prefers it aesthetically. We can then consider the greens and yellows common in the group, and the special Thrush-like colors of Ovenbird and Water-thrushes as concealing coloration, the wonderful diversity of color among the different species, as well as certain markings peculiar in position, color or shape (note the differently shaped white areas on the tails of Magnolia and Hooded Warblers) as a uniform enabling the species each to readily recognize its own; the high colors of the spring male as advertisement and display; and explain the woodpecker-like color of the Black and White Creeper, on aesthetic grounds. It is thus found that the colors of the familiar Warblers considered may be so far explained on the grounds of phylogeny and various more or less conflicting biological utilities, as to lead to the conclusion that these colors are by no means a haphazard product of evolution, but are controlled or determined by natural selection or some other force which is constantly adapting the bird to its complicated environment.

Deborah Allen and Robert DeCandido PhD Follow our Bird Sightings on Twitter: @DAllenNYC and/or @BirdingBobNYC

Bethesda Terrace (Central Park) in April 2009 - Black-and-white Infra-red image

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