That this is a warbler is clear from the shape of the bill.  Further, the pointed shape indicates this is a Vermivora.  The presence of obvious wing bars eliminates Tennessee, Nashville, and Orange-crowned.  We're left with Blue-winged or Golden-winged.  But this bird has an obvious yellow eye line and yellowish wing bars hinting at Golden-winged, while the yellow continuing down the breast and upper belly hint at Blue-winged.  Clearly, this is a hybrid, and one of the more frequent intermediates known as Brewster's.  This is not a typical Lawrence's as it lacks the bold black mask.  This bird cannot be aged or sexed based on this photo.

2b. Age this bird.     AHY

2c. Sex this bird.      Male

Given that this is a fall bird, it cannot be aged as SY due to the amount of black in the plumage.  It must be aged as AHY.  The amount of yellow mixed with orange is irrelevant to the age of this bird, field guide statements notwithstanding.  If this were a spring bird, it would also have to be aged as AHY.

This was the adult female that we caught this year.  It was aged by feather wear and sexed by presence of a brood patch, none of which are particularly visible in this photo.

This bird was aged as HY by skull.  There are no characters in the photo that would allow aging of this bird.  Sexing was not possible on the live bird.

5b. Sex this bird.     Male

That this is a Downy Woodpecker is clear by the short bill, which is shorter than the length of the head.  Bill is as long or longer than the head in Hairy.  Black spots in tail are helpful, but rare Hairy's have a spot or two!  Red on nape clinches sex as male.

An easy ID.  Head stripes distinguish from American Woodcock, which has head bars.  Note that the A.O.U. has split this species from Eurasian forms and the English name will revert to the older Wilson's Snipe.  Very likely there will be a change in species code.

7b. Age this bird.     U

The bill shape and brown streaky plumage make this an easy ID.  Asking the age of this bird was kind of a trick question.  There are no reliable aging features visible in this photo, so the age should be U as we cannot skull the photo! 

An easy ID.  Extra credit might have been obtained by sexing this bird as male based on the grayish, not buffy, cheeks.  This may or may not show well on your monitor.  The lack of buffy on the flanks are suggestive of AHY, which the bird is based on skull, but this is not a call I would make based on plumage visible in this photo.

9b. Age this bird.       AHY

9c. Age bird in 2nd photo.   HY

Another easy ID.  Eye color is subtly different, with the top bird showing a more lemon-yellow eye and the lower bird a more grayish-yellow eye.  These subtle differences may not show up well on your monitor, they're certainly very subtle on mine.  Nonetheless, you both correctly aged these birds.  If you had aged the birds incorrectly because of monitor variances, but indicated that eye color was the method, I would have given full credit.

Gray head, green back, bold white spectacles, and most important, a hook-tipped vireo bill clinch this easy ID. 

An easy ID.  Head bars distinguish from Common Snipe, which has head stripes.

Straw-yellow eye and rusty brown plumage distinguish this from Common Grackle and Red-winged Blackbird.  Extra credit may have been obtained by aging this bird as AHY based on the rusty incoming and blackish outgoing feathers on the breast and wings.  The glossiness on some of the shoulder feathers are also suggestive of male.

This was possibly the most difficult bird in the entire quiz.  It is probably a dull Alaskan race of Yellow Warbler which, though rare in the east, could occur at Holiday Beach since this photo was taken near Pittsburgh, PA!  The overall dull yellow plumage, with no distinguishing marks, is fairly similar to some very dull HY Yellow Warblers that we may see at HBMO in early August.  This bird is not a Nashville Warbler due to the shape of the bill (not pointy enough), the lack of a gray head, lack of a greenish back, lack of distinct white eye ring, the suggestion of wing bars in the coverts, and the yellow edging on the primaries.  This bird is not a Tennessee Warbler due to the lack of a pale superciliary and the suggestion of wing bars in the coverts.  The fact that the distinct yellow tail spots of the species are not visible makes this photo particularly difficult.  Note also that the correct species code for Yellow Warbler is YWAR.  One point is deducted for incorrect species code if it is close enough to be decipherable.

The rufous crown, grayish superciliary, and two-toned blackish and yellow bill clinch this easy ID. 

This nondescript warbler shows a pale superciliary, suggestion of streaking below, and lack of wing bars.  This bird is not a Cape May Warbler because of the lack of any wing bars, as well as the facial pattern and, more subtly, the bill shape.  This bird was aged as HY, but there is nothing in this photo to indicate this.

A dull, greenish warbler with a streaked back, dark feet, and some chestnut on the flanks are the keys to ID.  Extra credit could be obtained by sexing this bird as male based on the the amount of chestnut in the flanks, supported by the broad white wing bars and bold back streaking.  Though this is a HY bird, there are no reliable plumage features visible here to make that determination.

The large, rather pale bill and flat head is a good clue that this is a sparrow that would be unusual at HBMO.  The black crown stripes and white median stripe, as well as the complete eye ring are typical for the species, but the streaked cheeks and breast are not what we might expect, at least in a adult.  There is a suggestion of buffiness in the lores, but the pattern of breast streaking is typical for HY Grasshopper Sparrows.  Baird's Sparrow, which is extremely unlikely in eastern Canada, as well as Henslow's Sparrow can be eliminated by our bird's lack of any strong facial pattern, and for similar reasons, as well as bill and head shape, lack of a central breast spot, and lack of rufous lesser coverts, Vesper Sparrow can also be eliminated.  This is not a White-throated Sparrow because the chest is not gray, there is no dark malar, nor any dark line through the eye.  The median crown stripe in a White-throated Sparrow is not bright white as in this bird.  The lores on our bird are pale buff, not yellow.  Also, White-throated Sparrows have more obvious wing bars than this bird.  The tail feathers, if seen, would be quite different from sparrows we typically see at HBMO; they would be more pointed, almost spiky looking.

18b. Age this bird.     HY

18c.  How reliable is this aging technique?
According to the BBL, and Pyle (in fall), eye color very reliable in this species.

Species ID is pretty straightforward, with the large hook-tipped vireo bill and the white superciliary with a narrow black edge where it meets the gray crown.  Aging this bird is indeed done by eye color, and on my monitor the eye is definitely brown, not red, but apparently the eye can look black on some monitors, in which case a correct age would be U.  Pyle's warnings about this character involve spring birds only, and not birds with clearly brown eyes but birds with apparent intermediate eyes.  More experience at spring banding stations where this bird is caught in good numbers would be a good way to gain experience in how red an adult eye is, but then of course there won't likely be any birds with brown eyes (rare in spring) available for comparison.

This warbler's large size, large bill, and complete white eye ring are all helpful clues to ID.  The short-tailed look, with long under-tail coverts are also helpful.   Mourning Warbler is further eliminated by the whitish instead of yellowish throat, drab underparts, the complete eye ring, and plain lores.  Extra credit could be had by aging this bird as HY based on the lack of any sign of a gray hood on the head or breast.

20b. Age this bird.     HY

The pink-orange bill, broad brown crown stripes, and buffy central crown stripe and superciliary are clues to this bird's ID.  The brown crown stripes clinch the age as HY.  Note that the correct species code is EWCS, as even HY birds can be distinguished from "Gambell's" by their lack of buffy in the lores, continuing from the superciliary.  The lack of bright white superciliary, brown rather than rufous crown stripes, presence of an extensive buffy central crown stripe, and lack of dark lores eliminates Chipping Sparrow.

The large bill, yellow underparts, and diffuse gray hood eliminates all other warblers but Connecticut.  The bright yellow underparts, shorter under tail coverts, yellowish throat, and broken eye ring all eliminate Connecticut.  This bird could be sexed for extra credit, even not knowing the age (it happens to be a HY).  The lack of black on the chest is indicative of Female, particularly on AHY birds, but also on HY birds.

In July, HY birds will not yet show a pattern of dull, older feathers contrasting with newer, blacker, broader-tipped feathers.  In July, this is a good character for adult birds that can accurately be aged SY as the new black feathers contrast with the duller HY feathers, but becomes less useful in August as HY birds do begin molt as well.  The blackness of the inner greater coverts are indicative of a male.

23b. Age this bird.     AHY

23c. Sex this bird.      Male

The gray head, green back, broken white eye ring, yellow rump, and extensive white tail spots all make this ID straightforward.  Rect shape is often useful in many Dendroica warblers for aging, and this bird does show fairly typical truncate rects of an AHY bird.  The black at the base of the bill also support this.  Given the age, the sex can then be determined as Male again by the black at the base of the bill, the black upper tail coverts, and the large black centers on the green back.

24b. Sex this bird.     Female

The large golden wing patch and pointy Vermivora bill make this ID pretty straightforward.  This bird can be both aged and sexed by plumage.  Males of all ages will show black mottling or all black on the cheek and throat (Sibley is misleading here), so this bird is a female.  The brightness of the crown, and the extensive yellow secondary edging are good indications of an AHY bird, as HY females have very dull crowns, often mostly grayish.  Birds similar to this one, but with more than a couple yellow breast feathers, should probably be called "Brewster's" Warblers.

The grayish and whitish cheek, narrow whitish, not buffy, eye ring, and nondescript pattern of the lores (not buffy), eliminate Swainson's Thrush and clinch the ID as Gray-cheeked Thrush.  There were no takers for the easy extra credit for aging this bird as HY based on several greater coverts showing buff tips, and one even showing a little shaft streak.

The dark brown crown, white superciliary, shorter bill, black and white nape streaks, whitish underparts, and blackish tail all eliminate Carolina Wren.  Partial credit could not be given for the incorrect species code of MAWA, since that is assigned to another species, making it unclear whether the bird was correctly identified.

The thrush bill, rufous breast, black head with white markings, and gray nape and back all make this ID straightforward. 

The trio of Blackpoll, Bay-breasted, and Pine Warblers presents a challenging identification situation, particularly with HY birds (as this bird is, based on skull),  and given that all three species can range in overall back color tone from greenish to yellowish to buffy.  Our bird shows features of Bay-breasted, including a buffy eye ring (yellow in Pine), lightly streaked back (more streaked in Blackpoll, always unstreaked in Pine), unstreaked breast and flanks (typically streaked in Blackpoll), and peachy-buff flanks (whitish in Blackpoll, yellowish in Pine).  There is nothing in this photo that allows this bird to be aged or sexed.  It was skulled as HY and could not be sexed when in-hand (lack of chestnut flanks does not indicate female).  Sibley, in presenting direct statements with little variation in illustrations, is misleading by making it look easier than it is to age and sex warblers in the field.  The Peterson Field Guide to Warblers has the same failing.  Neither has undergone the rigors of scientific inquiry to prove their assertions.  Do not use field guides as the primary reference to age or sex birds during banding.  PYLE!

29b. Age this bird.     AHY

29c. Sex this bird.     Male

The conical bill and black-and-yellow plumage make this ID straightforward.  The outgoing black on the crown is enough to age and sex this bird, but additionally the black flight feathers support both as well.  The yellow shoulders may indicate an ASY bird, but closer examination would be required to determine if there was no black or olive mixed in there, and this character has come under suspicion recently for its usefulness for determining ASY.

Few birds are as dull as non-adult male Indigo Buntings, except perhaps female and juvenile Brown-headed Cowbirds.  Cowbirds are more grayish in tone, and larger than Indigo Buntings.  Compared with the hand in the photo, this bird is clearly small.  This HY-U Indigo bunting was aged by skull and could not be sexed.

31b. Sex this bird.     Female.

An easily identified warbler, with a yellow cheek, green back, breast streaks, and wing bars.  Again, Sibley and other field guides may lead us astray on aging and sexing, as often non-diagnostic characters are referenced.  This bird is clearly female based on the lack of black on the throat, and can even be aged by the shape of black intrusion on the white tips of the median wing coverts, all according to Pyle.

A small, pink-billed sparrow with a streaked crown, brown cheeks, a buff malar and black whisker, and gray nape can only be either HY Chipping Sparrow or Clay-colored Sparrow.  The diagnostic brown rump of Clay-colored (gray in Chipping) is just visible in this photo of an AHY bird captured in spring in Dearborn, MI.

Sharp, pointed bill, green back, yellow underparts, gray head, and complete white eye ring are all that is needed to correctly identify this bird.  Although it may be going out on a limb a little bit, there appears to be enough chestnut in the crown to sex this bird as male.  It was aged as HY by skull, and there are no plumage features in this photo that would allow aging.

34b. Age this bird.      HY

The bill shape of cuckoos is certainly diagnostic, and the fact that this one has a yellow bill clinches the ID.  HY Yellow-billed Cuckoos have pale yellow eye rings.

35b. Age this September bird.     AHY

35c. Sex this bird.        Male

Who could misidentify a male Northern Cardinal?  Certainly not either of you!  This bird's entirely orange bill may or may not be indicative of it's age, but fortunately I told you it was September, so a lack of dusky on the bill at that time of year clearly points to AHY.

Yellow throat, chest, and superciliary, along with dark "sideburns" and faint breast streaks clearly identify this bird.  Aging and sexing may not be possible from this photo (HY-U based on skull).

Once again we have one of the terrible trio of Blackpoll, Bay-breasted, and Pine.  The bird in this photo looks much greener than most Blackpolls we see at HBMO, but it is clearly not a Pine based on the streaking on the back, and the obvious pale feet, which also eliminates Bay-breasted.  The white under tail coverts also strongly support Blackpoll.  This HY-U was probably aged by skull. 

The very thin, pointed bill of this bird might suggest a Vermivora species, but no warbler in that genus would have the combination of broken white eye ring, pale yellowish breast with dark streaks, white wing bars, and grayish crown and back.  The key ID feature, however, is the small patch of yellowish-olive just behind the ear coverts.  This is about as nondescript as this species gets...most are easier.  This HY-F was aged by skull and sexed by features of the wing bars and tail not visible in this photo.

39b. Age this bird.       HY

The pale yellow breast with light streaks, and the obvious yellow under-tail coverts, along with the dark eye line and pale superciliary all point toward Palm Warbler.  Yellow-rumped Warblers do not have yellow under-tail coverts, and have a broken eye ring, not a pale superciliary.  The pale feet might suggest Blackpoll Warbler, but this bird is smaller, with shorter under-tail coverts, and of course Blackpoll Warblers have white or pale buff, not bright yellow under-tail coverts.  Yellow Palm Warblers (YPWA) would have the entire breast and belly brighter yellow, though there are many intermediate birds.  Aging this bird can be accomplished using rect shape, which is useful in many (all?) Dendroica warblers.  The rects are more tapered, not truncate, thus it is a HY bird.  The amount of white in the rects is useful, but often not diagnostic, for aging and sexing Dendroica.  This is also more difficult to use because comparative experience is necessary as the sizes of these spots are relative only within that species (i.e., a large spot in one species may be considered a small spot in another).

40b. Age this bird.     HY

Blue Jays are unmistakable.  The lack of black barring on the primary coverts indicates that this is a HY bird.  But, this is an aberrant individual with no barring on the median or greater coverts either, which virtually all HY Blue Jays have.  The lining of the mouth on this bird was nearly all black, indicative of adult!  In actuality, this bird was aged U, but based on what is visible in this photo an age of HY is acceptable.

41b. Sex this bird.     Female

The bluish-olive upperparts, pale yellowish-buff underparts, broken white eye ring, suggestion of a black mask, and small white mark at the base of the primaries all clearly identify this as a female Black-throated Blue Warbler.  Pyle makes mention of the size of this wing patch as useful for aging, but this clearly requires more study as I've skulled AHY-F birds that lacked the mark entirely!  Thus, there is no completely reliable way to age this bird from the photo (it was skulled as HY).

Again we have the diagnostic green back, yellow underparts, gray hood, and complete white eye ring of a Nashville Warbler.  An easy ID.

Differentiating HY Lincoln's Sparrow from HY Swamp Sparrow is not trivial, and often requires examination of wing formula and color of the roof of the mouth.  Fortunately, we have an AHY bird here (by skull), which shows all the diagnostic features for Lincoln's, including a narrow buffy eye ring, buffy malar with black on either side, grayish supercilium and cheeks, whitish throat, and narrow breast streaking washed with buffy.

Although similar to the previous species, note the extensive rufous in the greater coverts and tertials, the buffy rather than grayish cheeks, and an incomplete eye ring only covering the lower portion of the eye.  Aging Swamp Sparrows is accomplished only by skulling, the amount of rufous or black streaking in the crown is not at all reliable for this, and is quite variable.  Note that the correct species code for Swamp Sparrow is SWSP.

Obviously a sparrow, based on the conical bill, the streaked breast with the dark central breast spot is the diagnostic field mark.  But, some Song Sparrows lack the central breast spot, and in these cases the broad, blackish, triangular whisker mark adjacent to the buffy malar is very useful.  Note that although only one subspecies is likely at HBMO, there is considerable variation around the continent with dark birds in the Pacific Northwest, large ones (Fox Sparrow sized) in Alaska, and pale ones in the southwestern deserts.

46b. Age this bird.     HY

A gray bird with a black cap and thrush-like bill is unmistakably a Gray Catbird.  The crown is not particularly useful for aging catbirds, as I've never seen one of any age that had anything but a solid black cap.  Eye color has only recently been determined to be useful, and some researchers question this as well.  The eye of this bird looked clearly brown on my monitor, but it could surely look maroon (AHY) or even black on some monitors, so if you indicated that aging by eye was the method, but got it wrong based on your monitor's interpretation of the photo, I still gave you credit for a correct answer.  As with Red-eyed Vireos and White-throated Sparrows, it can be useful to handle birds in the spring to get a feel for eye color differences of adults.

47b. Sex this bird.     Male

Clearly a Carpodacus finch based on the conical bill and purple tones, the straight-edged culmen edge is a good distinction from House Finch, and the wine-colored cheeks, throat, and breast, with darker ear coverts is a good character for Purple Finch.  House Finch has a more reddish color concentrated on the supercilium and breast, with brown streaks, and the very unlikely Cassin's Finch has reddish color concentrated on the cap.  The coloration provides us the opportunity to sex this bird as male, and an additional opportunity to age the bird as AHY since HY males are female-like in all Carpodacus finches.

48b. Sex this bird.     Male

Green crown, gray cheeks, and complete white eye ring are all that is needed to identify fall-plumaged and HY Chestnut-sided Warblers.  The presence of chestnut on the flanks indicates this is a male, and the relatively small amount of chestnut is suggestive of HY, though skulling is much preferred for aging.  Some spring plumaged females can have some chestnut as well, so knowing the age of the bird is important before tackling the sex, a method useful for many species.

HY Carolina Wrens often have less buffy underparts than adults, but this is consistently different from the whitish or grayish-white of the virtually impossible Bewick's Wren.  Also note that the upperparts of Carolina Wren are richer rufous than Bewick's, though less so than the eastern subspecies, which has declined almost to the point of extinction.

The massive yellowish bill alone is enough to identify this as an Evening Grosbeak.  The all black wing wing coverts indicate this is an AHY bird (duller blackish-brown in HY), and therefore the gray head and back with yellow nape indicates this is a Female.

The flat-headed look to this sparrow should be a clue that it is something not often seen at HBMO.  In fact, this species is endangered in Canada so would be quite a find for us, but definitely a possiblity.  The mostly olive-colored head is a very good clue, as is the narrow, complete white eye ring, white throat with adjacent narrow black whisker, narrow streaks across the breast, black back feathers edged white giving a "scaly" appearance. 

Clearly a flycatcher based on bill shape, there is only one possibility that lacks an eye ring and has a dusky cap with pale yellowish underparts in fall. 

53b. Age this bird.     HY

53c. Sex this bird.     M

The olive back, brown cap, bright yellow throat, and suggestion of a black face mask are all good clues to this birds identity, age, and sex.  Use information in PYLE only to age and sex birds being banded.

The rufous cap, bright white supercilium, and black eye line and lores are excellent ID cues for this species.  Further, extra credit could be obtained by aging this as AHY, since HY birds do not have completely rufous caps. 

55b. Age this bird.     HY

This is a very unusual bird, and one that stumped me for a minute when I caught it in early August a few years ago.  The Juvenal plumage of Yellow-rumped Warbler is relatively unknown, as the birds molt out of it quickly after fledging, and the species nests more than 100 miles north of HBMO, so it is not a plumage that should be expected, but nonetheless here it is!  The bird did have a few yellow rump feathers growing in, otherwise the vague facial pattern of the species and bill shape would be most helpful.   Even though this birds is in juvenal plumage, it is capable of sustained flight (it flew 100+ miles from the nesting grounds to HBMO) and so must be aged as HY.  Many Cedar Waxwings retain their streaked juvenal plumage after they fledge too.  Noting that a bird is in juvenal [note spelling] plumage in a comments field, while reporting it as HY to the BBL, is highly recommended.

56b. Sex this bird.     Female

This and the next species make a good comparison.   Hooded Warblers are larger than Wilson's, though the sizes in the photos don't help.  Hooded Warblers have larger bills, and a much shorter yellow superciliary, with yellow from the throat intruding into the cheek and side of the neck, giving a shadow of the adult male hooded pattern, and generally not much contrast on the crown.  Hooded Warblers have more rounded tails and more pointed tail feathers, while Wilson's have more squared tails.  Not visible in this photo, Hooded Warblers have white tail spots, and Wilson's do not.  Female Kentucky Warblers have yellow "spectacles" with a dark eye line and some suggestion of dusky or blackish "sideburns" similar to the adult male's pattern.  There is nothing in this photo that would definitively allow this bird to be aged correctly (it is a HY).  This bird is duller than most female Hooded Warblers, fortunately!  Males have extensive black on the crown, nape, and neck.

57b. Sex this bird.     Female

Most of the ID criteria have been discussed above under Bird #56, but additionally the more contrasting cap is a good ID feature, as well as the lack of black being the principal indicator of the bird's sex.  Remember, Wilson's Warblers don't have white tail spots.

Yet another of our "terrible trio", this Blackpoll Warbler is showing fairly conspicuous yellow feet, as well as a streaked back and sides, and whitish under tail coverts.  The yellowish face, lacking any white eye crescents, is not correct for Yellow-rumped.

The older, outer buffy-tipped juvenile greater (not primary) coverts contrast with the newer whitish-tipped first prebasic inner greater coverts.

60b. Sex this bird.     Male

Is any discussion really necessary?  If you don't know this one, back to the drawing board! 

61b. Age this bird.     HY

This bird shows the grayish and whitish cheek, without buffy tones, as well as a mostly dusky loral area, all indicative of Gray-cheeked Thrush.  The buffy shaft streak in the inner greater coverts give the age of the bird away.

Foxy red face with gray supercilium, and large rufous blotches on the breast make this species unmistakable in the HBMO area.  Note that some western subspecies of Song Sparrow can approach this in size and appearance, so confirming with the bird's yellow lower mandible would be diagnostic (though Fox Sparrows look quite different out west too!).

This bird's rufous crown, grayish supercilium, and complete white eye ring distinguish it from Chipping Sparrow, and the pink bill distinguishes it from American Tree Sparrow. 

Although very similar to Song Sparrow, the lack of that species triangular whisker mark is helpful.  The yellowish in the lores is diagnostic for Savannah Sparrow.  Note that some (many?) Savannah Sparrows can show a dark central breast spot!

The bright, buffy-orange head markings and the sharply pointed tail feathers should be a clue that this is a bird not normally found at HBMO.  This species migrates from the prairies of Manitoba north to Hudson's Bay, to the southeast to winter on the Atlantic Coast, thus overflying the HBMO area.  This species is rarely observed on migration, but occasionally captured in mist nets!  It prefers wet, sedgy areas but could drop in almost anywhere.  Note that this bird also has white streaking on the back, black streaking on the breast, and a buffy throat.  The very similar, but extremely unlikely, Saltmarsh Sharp-tailed Sparrow, has a white throat with more sharply defined breast streaks.  A tan-striped morph of White-throated Sparrow would not be buffy on the sides of the neck or on the upper breast, and would not show such prominent black crown streaks or eye line.  White-throated Sparrows show two prominent white wing bars, which this bird does not.

66b. Sex this bird.     Female

The all gray back, yellow underparts, clear white eye ring, yellow lores, and suggestion of a dark "necklace" all confirm the ID as Canada Warbler.  The lack of black on the greenish crown, as well as the lack of any black in the necklace, indicate this bird is female.

This bird could pass un-noticed as a brightly colored Blackpoll Warbler at HBMO if you weren't paying attention to the bluish tones of the back and rump, which are often quite subtle.  Using Pyle (not Sibley), the lack of bright blue on the upperparts eliminates AHY-M, while the lack of streaks on the flanks eliminates AHY-F.  Thus, the bird is likely a HY bird.  Note that Pyle indicates using a combination of skulling, measurements, and plumage (primary white rect spots) to accurately sex HY birds.  The apparent lack of black streaking would suggest female, but a more thorough examination should be conducted before assigning a sex to this bird.

68b. Age this bird.     HY

68c. Sex this bird.      Male.

The conical bill, black head, breast, and wings, rufous flanks and white belly, clearly identify this species, and also clearly sexes the bird as male since females have brown heads.   Eastern Towhees are aged by eye color, similar to Red-eyed Vireos, and adults have a bright red eye.  If the eye on this bird appears bright red on your monitor, you should age it as AHY.  If it appears brown (as on mine), you should age it as HY.  This bird was aged in the field as HY based on the brown eye.  Note that adults in the southeast have whitish eyes!

The yellow throat curling up around the ear coverts is certainly enough to call this ID, but further points include the bright yellow underparts with bold blackish streaking, and the large white wing patch.  Western Palm Warblers could have a throat this yellow (but confined to the throat), but would not have the breast and belly so white, nor have a yellow supercilium or large white wing patch.  Yellow Palm Warblers would be less streaked below and would lack the yellow supercilium and white wing patch.  The size and extent of white in the wing are indicative of this being a male, and the lack of chestnut in the cheeks indicates this is a HY bird.

The yellow crown and underparts, black lores and short eye line, bluish wings with white wing bars, all support the ID as Blue-winged Warbler.  Only AHY-M birds show as much yellow on the crown, meeting the olive of the hindneck abruptly rather than indistinctly, as this bird does.

71b. Age this bird.     HY

The contrasting rufous tail and rump clearly identifies this species, and the prominent buffy shaft streaks in the greater coverts ages the bird as HY.

72b. Age this bird.     AHY

72c. Sex this bird.      Male

Showing the classic featurs of a "Lawrence's" Warbler, including the black mask and throat of Golden-wing, the yellow face of Blue-wing, the blue wings and white wing bars of Blue-wing, and the yellow underparts of Blue-wing, this bird can also be sexed as male due to the black mask, and AHY for similar reasons.

73b. Age this bird.     AHY

73c. Sex this bird.      M

Lemon yellow head, breast, and belly, along with white under tail coverts, and black "beady" eye easily identify this as a Prothonotary Warbler, one of our nesting birds at HBMO.  The shape of the rects is truncate, indicating an AHY bird.  The crown seems to get duskier in fall birds than the field guides would indicate, and the fleshy-gray base of the lower mandible is not mentioned anywhere I've been able to find!  The large amount of white on the outer rect is indicative of a male.

74b. Age this bird.     SY

74c. Sex this bird.      M

I knew this would be difficult, but I didn't think the ID was impossible!  Both of you got the main point, that this is a SY bird based on the extremely obvious molt limit shown by the older brown feathers contrasting with the newer black feathers.  In fact, this condition would only be seen in spring birds in this species.  It is a male based on the new black feathers.  This is not a Downy Woodpecker, as Downy does not have a large solid white area in the primaries, nor a solid white area on the median coverts.  Rather, Downy Woodpeckers have numerous white spots on all the wing feathers, rather uniformly distributed.  This  is not a Red-headed Woodpecker, as all ages and sexes of Red-headed have all the secondaries white (similar to where the brown feathers are, but more extensive), which have a dark bar in HY birds.  Red-headed Woodpeckers do not have any other white in the wing other than this single square in the secondaries.  Northern Mockingbirds and Northern Shrikes have much smaller white patches in the primaries, and none in the median coverts.  

The gray hood, complete white eye ring, large feet, and long under tail coverts all combine to ID this bird as a Connecticut Warbler.  Nashville Warbler has a yellow throat and shorter under tail coverts, and perhaps less helpful, smaller feet.

76b. Age this bird.     HY

76c. Sex this bird.     Male

I knew I couldn't get you guys to fall for this one twice!  Clearly it is a House Sparrow, and the incoming rufous on the head and black on the face and throat indicate a HY Male bird.

77b. Age this November bird.     HY

77c. Sex this bird.     F

The black face and bright red, conical bill are unmistakable for Northern Cardinal.  Since this is November, a male bird would definitely have more red in the face and crest, so this is clearly a female bird.  The fairly indistinct dusky area on the culmen ridge is a retained juvenile characteristic that, if absent in November prevents you from aging the bird, but if present allows it to be aged as HY.  This marking may be difficult to see in this photo, but sometimes you have to look hard for things on birds in-hand too, just to be sure!

The whitish throat, white eye crescents, streaked breast, and yellow flank patch, along with a tiny area of yellow rump visible, clearly identifies this bird. 

79b. Age this bird.     HY

The white and black striped crown, yellow loral spot, and white throat all clearly identify this as a White-throated Sparrow.  On my monitor, this bird's eye looks grayish-brown, thus aging it as HY.  This character may be too subtle for you to be sure, depending on your monitor.

I couldn't resist putting an Empid into the mix!  If you simply called this an Empid, or identified it as any Empid, I gave you two points.  It is not a Yellow-bellied as the back color is not green enough.  It is not a Traill's because there is contrast between the olive back and gray crown, and the eye ring is too prominent for most Traill's.  It is too small and not green enough for Acadian.  It looks rather small, short-tailed and short-billed, but if I were in court, I would be unwilling to testify that this was a Least beyond a shadow of doubt, other than the fact that I took the photo and know what the measurements were.

81b. Sex this bird.     Female

U- , sex by plumage 

The chisel-like woodpecker bill, red crown, black whisker, and black chest identify the species.  The white throat indicates a female.  The age of the bird cannot be determined, other than that it is not a HY bird (they're brown not black) without examining wing molt.

The yellow breast and throat, greenish back,  grayish head, black lores, and white spectacles combine with the thick chat bill to identify this bird.

83b. Sex this bird.     F

The chisel-like woodpecker bill, gray head, and red nape patch identify this as a flicker.  The absence of a black whisker mark (there isn't a suggestion of one here, just displaced feathers) is a definitive mark of female.  Even nestlings in the nest can be sexed by this mark.  Age can only be determined by examining the wing molt (anyone?).

The small size, wren bill, prominent buffy superciliary, and short tail all indicate this is a Winter Wren.  Measure the tail length on difficult birds to separate from House Wren. 

The thrush bill, rufous crown and wings, and bold round spots evenly distrubted on the underparts clearly identifies this bird. 

86b. Age this bird.     AHY

86c. Sex this bird.      Female

The red shoulder patch and streaky plumage are the best ID marks for this bird.  But, the amount of red on the shoulder, combined with the streaking is potentially confusing.  This is another aberrant bird! AHY-M Red-winged Blackbirds would have much more black in the body plumage with this much red in the shoulder, so this is not an AHY-M.  HY birds, in general, won't have this much red in the shoulder, and HY-M won't have the peachy-buff throat shown by this bird.  This is an AHY-F showing more red in the shoulders than typical.  It is AHY based on the peachy-buff throat, which is infrequent in HY-F and absent in HY-M.  It is female for the same reason, plus the lack of black body plumage, given that it is an AHY bird.  Remember to check the under wing coverts for contrast to verify a bird's age, along with skulling (sometimes difficult).

87b. Age this bird.     AHY

87c. Sex this bird.      M 

The diagnostic tanager bill, showing a small tomial notch half way down the upper mandible, gets us to the right family.  The all black wings gets us to Scarlet Tanager.  Both HY and AHY female Scarlet Tanagers have greenish wings, and HY male scarlet Tanagers also have greenish wings, which molt through fall and winter to black.  Since this bird appears to have all black wing feathers, with no mixed green, it must be an AHY-M.

88b. Age this bird.     U

88c. Sex this bird.      Male

The ruby crown, "teardrop" eyering, and broad black wing bar behind the white wing bar all identify this as a Ruby-crowned Kinglet.  The red crown patch indicates a male, but aging the bird is more of a problem.  There are not reliable plumage features visible in this photo to age this bird.  IF the wing coverts appear uniform, and with fresh green edging and distinct white tips, this may point better to HY, but this character alone is not reliable.  Rect shape, which cannot be determined here, is more reliable, and often helpful but requires a fair amount of experience.  Therefore, this bird should be aged as U.

Another of the "terrible trio", this one shows distinctly yellow eye crescents, much yellow below, and an unstreaked green back.  It is not a Mourning Warbler as this bird has wing bars and Mourning Warbler does not, in addition to this bird having a green head, which is gray in Mourning.  

The small, hooked vireo bill, and the white superciliary leads us to either Warbling or Philadelphia Vireo.  The black lores clinches the ID as Philadelphia, but the amount of yellow on the throat and breast is rather more than even the yellowest HY Warbling Vireo would have.  Also, the contrasting blue-gray crown, vs. plain gray in Warbling, and greenish back, are helpful.  Remember to check the length of p10 relative to the primary coverts on difficult individuals.

The brownish tones, streaked underparts, and bold superciliary indicates this is a waterthrush.  The narrowing behind the eye, and the presence of spotting on the throat, indicate this is a Northern Waterthrush.  Other useful characters include buffier flanks, and often a two-toned superciliary in Louisiana.  Remember to check the bases of the under tail coverts in birds that are difficult to ID in hand.

The small size eliminates thrushes, and the orange and black striped crown clinches this ID. 

93b. Sex this bird.     M

While bill shape is useless at this angle, suffice it to say this is a warbler.  The bill is orange at the base, and the crown is bluish.  Only one warbler is marked this way.  The presence of dusky and rusty feathers in the breast band are clear indications this is a male.

In most Dendroica warblers, rect shape can be very useful for aging.  These rects are an excellent example of what "truncate" looks like.  Size of tail spots are less useful for aging than for sexing, and varies in usefulness by species.

The pointed bill is clearly that of a Vermivora, and the overall greenish and yellowish plumage, with the only redeeming field mark being the pale superciliary, is a good indicator that this is a Tennessee Warbler.  The noticeable, but tiny, yellow-olive tips on the greater coverts (see Pyle) may be an indication that this is a HY bird, but skulling would be preferred (it skulled as a HY).

96b. Sex this bird.     Male

The little wedge-shaped bill is clearly that of a nuthatch, and  the black-and-white head along with the rich buffy underparts identify it as a Red-breasted.  Males have black crowns contrasting with the blue-gray backs, while females have blue-gray crowns.

97b. Age this bird.     AHY

97c. Sex this bird.      Male

The overall yellow coloration with distinct black streaks and facial markings of this species are unmistakable.  The brightness and boldness of the flank streaks and facial markings are indicative of AHY-M.

98b. Age this bird.    HY

The plump proportions and wedge-shaped bill identify this as a rail.  The shortness of the bill eliminates all but Sora and Yellow Rail.  Yellow Rail is much buffier above and below.  Adult Sora's have a gray breast and a distinct black face and throat marking.

99b. Age this bird.     AHY

99c. Sex this bird.      M

Clearly a raptor based on the hooked bill, and clearly a Sharp-shinned Hawk based on the size of the bill and dark gray nape (Cooper's is pale).  This bird is AHY based on a lack of brown feathers in the back and the deep burgundy eye.  The size of the bird can be judged in comparison with the hand holding it, and it appears small, but to be sure of the sex measurements should be taken.  

Here is another vireo with a fairly small, hook-tipped bill and a short pale superciliary.  This bird has a little yellow on the flanks but not on the breast or throat.  The grayish crown contrasts little with the olive back, and there is not much of a dark spot in the lores, giving this bird a "plain-faced" look.  Remember to check the length of p10 relative to the primary coverts on difficult individuals.

101b. Age this bird.     AHY

Well, it COULD occur!!!  Just for fun, this Green Violet-ear is similar to only one other hummingbird, Sparkling Violet-ear, which is South American and not ever recorded in North America.  The Sparkling Violet-ear has an extensively blue-violet chin connecting with the blue-violet ear patch.  Sparkling Violet-ears are also larger, with longer, straighter bills.  Unlike many hummingbirds, Green Violet-ears can be aged by plumage characters.  HY birds have dusky gray-green chests and grayish bellies, while AHY birds have bright blue-green bellies, as does the bird in this photo.