Answers to eBird Fall Photo Quiz -- The power of suggestion

Compared to identifying birds in the field, identifying birds from photos is sometimes easier, but often much harder. While you often don't have the very important clues of likelihood (but we did give you location and month on these!), habitat, behavior, and calls, you do have (in these photos) very good, close-up views of birds that are not moving, and they won't fly away before you get out your field guide. Some truly excellent birders were tricked by this quiz, often by species that they routinely identify at a glance; or as a distant heat-shimmering image in their scopes; or based on a short chip call or scold note from the underbrush.

We subtitled these answers "The power of suggestion", and after taking the quiz many of you probably realize why. While the quiz results were overall excellent, with the majority identifying almost all species correctly, there were two notable exceptions: Quiz photo #5 and Quiz photo #7, both with correct score percentages only in the teens! These were certainly not easy to identify birds, but the very low scores likely reflect the fact that on both of these questions the correct answer was "Other" and users had to fill in the  species. Our quiz-takers were beguiled by the list of answers in front of them...

In reality though, bird identification in the field is not a multiple choice process. While most experienced birders do have a mental list of species that are likely on a given date and a given location (sort of like the eBird data entry checklists), these expectations often play a larger role than they should in the process of objectively identifying what we see in the field. A few frequent examples are: encountering a rare bird out of season or out of typical habitat and assuming it is a more expected species; encountering a common bird in a slightly unusual plumage and deciding it must be a rarer species with which you are less familiar; or, quite simply, going along with a suggested identification when birding in a group. If there is one lesson to be learned from this quiz, it is to always consider a bird identification independently. It is very common, even among expert birders, for the power of suggestion within a crowd to steer a group of birders in the wrong direction. It is a rare skill indeed to consider every bird ID independently, on your own, and admit without any shame when you are unsure, and to discuss openly any identification that you consider to be open to question.

On the two examples where 'Other' was the correct answer below, notice just how many birders were led astray by our devilish and quite intentional trick of putting similar species as the four primary options, but leaving the correct identification off the list altogether. In one case, we did not even provide any options in the correct family!

 

Quiz Photo 1 -- Surf Scoter (66.2% correct)

Other species selected: Black Scoter (10.3%), White-winged Scoter (10.3%), Ruddy Duck (9.4%), American Black Duck (3.2%), and Other (0.6%)

Surf Scoter by Brian L. Sullivan (November, California)

 

Immature and female ducks are difficult for many birders, but with attention to shape and structure, and some subtleties of plumage pattern, most can be identified. Often the females are shaped very much like the males. 

Ruddy Duck is a small, squat, low-slung duck with a tail usually held clear of the water and cocked upwards. Since behavioral cues like this can be misleading, and since scoters occasionally point their tails skyward like a Ruddy, we should dig deeper here. The face pattern is unlike a Ruddy, which would show either bright white cheeks or a whitish cheek bisected by one or two dark lines.

American Black Duck is shaped much more like a Mallard with a round head, slim neck, and high rear end with a tail that sits clear of the water and forms a point at the rear of the bird. In addition, the bill is usually greenish and the head is pale across the face, without noticeable pale spots.

Female Black Scoter, looks quite a bit like American Black Duck in general pattern, so also would not show prominent face spots. The head of Black Scoter is typically quite rounded with a steep forehead, not the sloping forehead of this bird. the bill also appears quite small compared to the head and is not so thick-based.

Female White-winged Scoter is perhaps most similar, and you certainly should not rely too heavily on the white wing patch to pick them out, since that patch can be concealed. Identifying female White-winged and female Surf Scoters is a challenge, but concentrate on the head shape: Surf has a blocky, squarish head and a very deep based bill while White-winged Scoter has a more rounded head with a long sloping forehead that forms a somewhat bumpy profile (on American subspecies deglandi). The bill of female Surf Scoter is shaped just like a male's, with a straight juncture with the face and thick base--on this bird you can almost see the hints of the male bill pattern. White-winged Scoter has a point of feathering reaching in from the sides of the bill, giving a quite different shape. These different bill shapes also affect the shape of the white spot at the bill base, with Surf having a white spot oriented vertically and White-winged Scoter having a spot oriented more horizontally.

Quiz Photo 2 -- Barn Owl (54.1% correct)

Other species selected: Short-eared Owl (16.5%), Northern Harrier (10.9%), Ferruginous Hawk (14.7%), Red-tailed Hawk (3.3%), Other (0.5%)

 

Barn Owl by Brian L. Sullivan (September, California)

 

Although most of our quiz photos were birds in nice profile shots showing all the possible field marks, this was the one photo that showed a bird in a really unusual posture. Everyone seemed to agree that it was a raptor, but whether it was a hawk or an owl was not unanimous.

In this case, the head is facing away, but it does give the impression of being a big-headed, thick-necked, and flat-faced bird, like an owl. And it is.

Identifying birds from these atypical views often requires focusing on different sets of field marks. In this view, we can see the underwings really well. The gleaming white inner wing and lightly barred buff and dark outer primaries (wingtips) provide a unique pattern. The rather orangeish breast is also distinctive.

Of the other contenders, the hawks (Red-tailed and Ferruginous) have underwings with more markings than are shown on this bird and the barring on the primaries and secondaries is much more extensive). The very rounded wing is owl-like and not like the heavily-patterned and barred underwing of a Northern Harrier. In addition, none of these species approach this buff-orange breast in any plumage.

Short-eared Owl is surely the most similar, but it too has a more heavily marked underwing, and at best is pale buff-brown on the breast, not the rich buff-orange of this bird.

Barn Owls aren't often seen hunting during the day, but it does happen occasionally, as with this bird.

Quiz Photo 3 - Bay-breasted Warbler (59.2% correct)

Other species selected: Chestnut-sided Warbler (21.5%), Pine Warbler (10.5%), Blackpoll Warbler (5.1%), Tennessee Warbler (3.4%), Other (0.3%)

 

Bay-breasted Warbler by Christopher L. Wood (October, New York)

 

When Roger Tory Peterson coined the phrase 'confusing fall warblers', he was likely thinking largely of Chestnut-sided, Bay-breasted, and Blackpoll, which look very different in fall and spring plumages! This Bay-breasted is from fall.

Of the options selected, Tennessee Warbler is the easiest one to rule out, since Tennessee Warblers do not have prominent white wing bars. That species would also not show gray on the rump and base of the tail and should show a more prominent eyebrow.

Chestnut-sided Warbler was a popular guess, presumably because of the wash of buffy color on the flanks. But Chestnut-sided in fall plumage has a bold, complete white eye ring and does not have blackish streaks on the back. Its tail it quite long, almost gnatcatcher-like, and its underparts tend to be quite whitish.

Pine Warbler can look pretty similar, but never has pinkish-buff on the flanks like this. Pine Warbler also does not show a black streaked back, tends to look a bit chunkier, and should show more yellow on the breast if it is showing yellowish up around the throat and ear coverts.

Blackpoll vs. Bay-breasted Warbler can be a very challenging identification, but when the bird is still showing bay color along the flanks it does make it significantly easier. Once Chestnut-sided Warbler is eliminated, this feature alone should help get the ID to Bay-breasted. Other characteristics to tell it from Blackpoll include the less prominent eyeline giving a more 'gentle' look to the face, the lack of olive streaking on the underparts, and the very pale yellowish-green on the head and nape vs. the more olive color on Blackpoll. Some Blackpolls have distinctive pinkish legs, but others have dark legs like this (although such birds usually have yellowish or pinkish soles to the feet, which are actually partly visible here and look pale gray).

Quiz Photo 4 - Black-capped Petrel (76.7% correct)

Other species selected: Great Shearwater (10.0%), Cory's Shearwater (5.8%), Bermuda Petrel (3.9%), Buller's Shearwater (3.1%), Other (0.6%)

 

Black-capped Petrel by Brian L. Sullivan (May, North Carolina)

 

For a normally pelagic bird that is very rarely seen by anyone, this was an impressive result! Great job eBirders!

Of the options in the list of choices, Cory's Shearwater is most easily eliminated, since they always have pale bills with dark tips. Cory's also does not show much white when seen from above (they generally appear tan or sandy-colored), and never have prominent pale collars or extensive white uppertail coverts.

Buller's Shearwater is also unlikely, since it lacks pale uppertail coverts and a pale collar. Buller's are also strikingly patterned above, with gray upperparts and a prominent black 'M' pattern above.

Great Shearwater is often confused with the quiz bird, since their general pattern is similar. When seen at this range, bill shape may be the most obvious difference: on all shearwaters the bill is very slender with the length more than three times the depth. On the quiz bird, the proportions are much different, with a short thick bill that appears only about twice as long as it is deep. In addition, Great Shearwater always shows a more restricted patch of white on the uppertail coverts, has a dark brown cap that reaches the bill, and does not have as prominent a white collar. They often tend to look scaly brownish above too, unlike the relatively flat and even-tones of the quiz bird.

It is Bermuda Petrel that is perhaps the biggest identification concern. It also has a comparatively short and thick bill, but the overall size of the bill is much smaller in proportion to the rest of the bird. Compared to Black-capped Petrel (like the one pictured here), Bermuda Petrel is slimmer winged and usually lack the white collar and has much less extensive white uppertail coverts. Typically, a Bermuda Petrel looks like it is wearing a dark shawl, that sweeps across the nape and down in front of the wings. A few Bermuda Petrels have now been identified that have white collars and white uppertail coverts, and for these birds, focusing on the smaller bill and narrower wings may be the best characteristic (although their collars tend to be much smaller compared to this bird).

To take this identification just a bit further, this bird appears to be a clear example of the dark-faced form (as defined by Howell and Patteson 2008). As an example of the frontiers of birding that are still not well understood, Steve Howell and Brian Patteson have questioned whether different forms of Black-capped Petrel may represent distinct species (Howell, S. N. G., and J. B. Patteson. 2008. Variation in the Black-capped Petrel: one species or more? Alula 14: 70-83). The Neotropical Birds page gives a summary (including photos of both forms).

Quiz Photo 5 - Bobolink (13% selected "Other" and filled this in)

Other species selected: Le Conte's Sparrow (29.9%), Grasshopper Sparrow (29.1%), Baird's Sparrow (13.0%), Savannah Sparrow (13.0%), Song Sparrow (3.0%)

 

Bobolink by Brian L. Sullivan (October, New York).

 

Mean, downright mean. Not only did Team eBird not provide this bird in the multiple choice, but we picked a photo of a Bobolink sitting down in the grasses feeding like a sparrow...and then we gave a long list of buffy sparrows to choose from.

This is, in fact, a Bobolink. All fall Bobolinks look more or less like this, as females and immatures wear a nice buffy wash to the breast and males molt from their striking black and white plumage to these more subtle tones. Experienced birders rarely struggle with them since they fly up from the grass in flocks (in a totally un-sparrow-like fashion), give resonant 'bink' notes that prompt reflexive oral identifications from many birders, and are overall much larger than any sparrow other than a towhee!

But, along with female Red-winged Blackbird and female Brown-headed Cowbird, this subtle bird in brown plumage can cause ordinarily unflappable birders fits when it appears out of context. So, some consideration of the other sparrow options is warranted.

Since Bobolinks look so sparrow-like, and since sparrows are so variable, there aren't many single field marks to eliminate all sparrows. But no sparrow matches the strong lateral crown stripes with a central crown stripe that does not contrast (Grasshopper and Le Conte's have contrastingly whitish crown stripes, while Nelson's and Saltmarsh have contrastingly gray ones).

Le Conte's Sparrow (juvenile) at Cape Elizabeth, Maine, Oct 2010 by Luke Seitz. Note the almost non-existent primary projection! The same would be true for Grasshopper Sparrow (almost for any sparrow).

If you really need convincing, however, look at the primary projection on this bird (i.e., the length of the wing, specifically how far the primaries extend past the tertials). Bobolinks are highly migratory, heading to southern South America for the winter. Sparrows, for the most part, winter in the southern United States. Nearly all sparrows (and especially the genus Ammodramus, of which we provided three options in this quiz) have very short wings that barely extend past the tertials. On this Bobolink, the length of the primaries past the tertials is about as long as the tail!

MUCH longer primary projection!

Beware of the sparrow look-alikes, like Bobolink, in the fall!

Quiz Photo 6 - Fox Sparrow (79.2% correct)

Other species selected: Song Sparrow (10.0%), Lincoln's Sparrow (6.2%), Swamp Sparrow (3.1%), Purple Finch (1.3%)

Fox Sparrow (Red) by Christopher L. Wood (October, New York)

 

This one didn't present too much trouble for our audience, which is great. Fox Sparrow comes in a number of forms (which may involve up to four species). Only the 'Red' Fox Sparrow (in eBird as "Fox Sparrow (Red)" is the only form found throughout the East, and it is the one shown here. The large blurry reddish spots, yellow bill base, and grayish face are all key features of 'Red' Fox Sparrow.

Purple Finch is actually similar to this bird in many ways, with similarly broad, blurry streaking on the breast and flanks. However, the lack of a well-defined facial pattern, the yellow bill base, and the rich reddish color of this bird all eliminate Purple Finch.

Swamp Sparrow is never so heavily marked on the breast and always shows a gray breast. The most heavily marked immatures have pencil thin streaks on the flanks and central chest, but never have spots, chevrons, and blotches like this bird. Lincoln's Sparrow, similarly, always have very fine streaking and should show a buff wash across the breast.

Song Sparrow is perhaps most similar, especially birds of the desert Southwest that have breast streaking that is similarly reddish against a white background. But no Song Sparrow ever has a breast that is so spotted (versus streaked). Furthermore, the gray face of this bird is distinctive, as is the thick-based bill with extensive yellow.

Quiz Photo 7 - White-rumped Sandpiper (12.9% selected "Other" and filled this one in)

Other species selected: Baird's Sandpiper (34.4%), Western Sandpiper (20.5%), Semipalmated Sandpiper (19.8%), Sanderling (9.5%), Red-necked Stint (2.9%)

 

White-rumped Sandpiper by Christopher L. Wood (September, New York)

 

The power of suggestion at work again--the correct answer was again not listed among the multiple choice options!

Shape is so important with shorebirds that we should start there in trying to identify this bird. The relatively short legs, short bill, and general proportions peg this as a sandpiper in the genus Calidris, sometimes collectively referred to as 'peeps'.

This bird seems strikingly long-winged and a close check reveals that the wingtips do extend a centimeter or two past the tail. This character alone essentially eliminates Red-necked Stint and Semipalmated Sandpiper, which are both comparatively short-winged. Those birds also have quite pale breasts at all seasons and usually do not show the grayish face with a white eyebrow that is so prominent on this bird.

Sanderling is chunky, squat shorebird and not particularly long-winged either. They also tend to be very pale and whitish, and either very pale whitish gray on the back or prominently checkered with black and white.

Baird's Sandpiper is structurally very similar to this bird, with the same long wings extending past the tail. But Baird's is brown (or buff...good mnemonics since they start with "B"). This bird looks overall grayish with no warm tones or hints of buff or brown.

In fact, this is typical for White-rumped Sandpiper, which is shaped like a Baird's (long wings!) and also shows the prominent white eyebrow. The fine, sharper streaks just below the bend of the wing are typical for White-rumped Sandpiper too. This adult is losing its breeding plumage, but in summer they show extensive streaking down the flanks. There are a couple hints of those streaks still visible. Baird's vs. White-rumped is very difficult when not seen well, but the overall color usually gets you to the right ID.

However, beware the power of suggestion. We did not include White-rumped Sandpiper in the list of options and as a result many birders tried to force this bird into another species. Unlike this photo quiz, remember that eBird always has 'peep sp.' available if you are unsure!

Quiz Photo 8 - Warbling Vireo (43.1% correct)

Other species selected: Philadelphia Vireo (36.4%), Tennessee Warbler (12.4%), Orange-crowned Warbler (6.8%), Red-eyed Vireo (0.9%), Other (0.4%).

 

Warbling Vireo by Christopher L. Wood (September, New York)

 

This was surely the hardest photo in the quiz, and some of the better birders that we know called it a Philadelphia Vireo. It is a vireo, and the somewhat thick bill and largish blue-gray legs and feet are two good indications that it is a vireo and not one of the warbler options. Red-eyed Vireo would have bold blackish crown stripes and should show a red or reddish-brown eye. So this brown-eyed vireo, without wing bars, is sure to be either Warbling or Philadelphia.

Philadelphia Vireo at Monhegan Island, ME, by Luke Seitz

An under-appreciated problem is just how similar fall Warbling Vireos can look to Philadelphia Vireos (above). Field guides stress to look for the brighter yellow of Philadelphia and the dark lores. But the quiz bird could be interpreted to show bright yellow below and dark lores.

Focusing on the yellow underparts though, notice how there still seems to be some white or paler color (pale yellow maybe?) running down the central chest. This starts in the throat goes at least to the upper breast. It seems that if the bird were facing you, it would have a paler strip down its midsection. The sides of the breast are clear pale yellow and seem to be the brightest area on the bird. On Philadelphia Vireo, by contrast, the central breast is the brightest yellow on the whole bird (see the above photo from Maine). While some Warblings can be very bright yellow below, no Philadelphias have pale areas in the central chest.

The lores (area between eye and bill) of this bird are clearly 'dusky' on the quiz bird, but they don't really contrast with the rest of the face. The whole effect is of a pretty 'blank-faced' bird, with a dark eye staring out from a pale face. Compare that to the Philadelphia Vireo above: that bird has a narrow but prominent whitish eyeline; the lores are actually contrasting darker than the face; the cap appears to be set off more distinctly from the face. The whole effect is of a crisper, more strongly patterned face on Philadelphia and blank, less strongly demarcated face on the Warbling. Another way to think about the different facial expressions is that Philadelphia Vireo very much had a pale supercilium ('eyebrow') and a dark eyeline, and that the supercilium extends to the base of the bill and cuts off the cap from reaching the bill. On Warbling, the pattern is usually of a shorter supercilium that starts behind the eye, gets wide over the eye, and then wraps around the front of the eye to connect with a wide pale area below the eye. The supercilium on Warbling often does not reach the area where the cap touches the upper bill base. One the quiz bird this 'wrap-around' the front of the eye is bisected by medium grayish lores, but the general impression is still more like Warbling and very unlike that shown by 'Philly' Vireos. The 'looks' of these birds are indeed different, if subtle.

One lesson here is not to over-emphasize 'yellowness' of a vireo in fall. You can expect to find very yellow Warbling Vireos at this season; just be sure to concentrate more on determining where the brightest yellow is on the underparts. Do your best to get a look at the face pattern and listen for calls if they give any. And when unsure, feel free to use vireo sp.!

Quiz Photo 9 - Black Tern (54.2% correct)

Other species selected: Bonaparte's Gull (17.4%), Little Gull (10.6%), White-winged Tern (8.7%), Common Tern (8.4%), Other (0.6%)

 

Black Tern (North American) by Brian L. Sullivan (September, California)

 

Pointy-winged small gulls and terns can sometimes present challenges, especially at a distance. Not only are Bonaparte's and Little Gulls (and Black-headed and kittiwakes) tern-like in their small pointed bills and very slender, pointed wings, but they also share the general pattern of having dark spots or smudges on the ear coverts that his bird shows. However, the bill of this bird is more tern-like than gull-like and the pattern of its upperwing is unlike Bonaparte's Gull or Little Gull, which always have pale gray, whitish, and black on the wingtips (except for adult Little Gull, which has a pale gray wing with a white terminal border). For those that got this to Common Tern, Black Tern, or White-winged Tern, you were on the right track.

Common Tern is maybe a bit more challenging to eliminate, but it too is very pale above, with pale gray upperwings contrasting strongly with a dark brown carpal bar. The finger of dark extending down the breast sides in this bird also eliminates Common Tern, which is always white in this area. Head pattern further helps eliminate Common Tern, which has a solid black half-hood (or a solid dark hood with an extensive white forehead). This bird, with a small skull cap connected to a dark ear spot, almost gives the impression of having sideburns. The tail is also not as long and strongly forked as a common Tern, and the grayish tones to the rump and uppertail also eliminate Common Tern and other Sterna terns.

White-winged Tern can look very like Black Tern in juvenal and winter plumage. The best single field mark is the dark spur projecting on to the breast sides, which is never shown by White-winged Tern. When seen better from above, the tail and rump of this bird would be more grayish without a contrasting white rump. The ear spot that connects to the skull cap is also unlike most White-winged Terns, which tend to have a head pattern more like Bonaparte's with an isolated black ear spot. The dusky flanks and underwing coverts are not shown by White-winged Terns (but are shown by Eurasian Black Terns; see below). This Black Tern is in juvenal plumage, evidenced by the wash of brown on the nape and neck sides and the generally very fresh plumage.

For those that like new challenges, try identifying this bird to subspecies! There are two forms of Black Tern available in eBird: "Black Tern (North American)" and "Black Tern (Eurasian)". They are very similar but identifiable in the field in all plumages. For birds in juvenal and winter plumages, watch for the gray wash along the flanks and grayish underwing coverts on American Black Tern (as on this bird). The gray wash on the flanks meets the breast spur that is preset on all Black Terns (and a good character to eliminate White-winged Tern). There have been suggestions that the two forms might be granted species status in the future, so practicing up on how to recognize a vagrant on the wrong continent is worthwhile! To read up more, track down this superb article: Hallam N. and Lewington, I. 2009. Identification of American Black Tern. Birding World 22: 383-388.

Here is a nice 'American' Black Tern to compare with this 'Eurasian' Black Tern.

Quiz Photo 10 - American Pipit (69.9% correct)

Other species selected: Red-throated Pipit (13.3%), Lapland Longspur (8.1%), Smith's Longspur (6.3%), Other (1.4%), Savannah Sparrow (1.3%)

 

American Pipit (Siberian) by Brian L. Sullivan (November, California)

 

So, by this point in the quiz, everyone should be expecting trick questions from Team eBird. This one was a trick too, since typical American Pipits (the ones breeding in North America that is) do not have pink legs. For North American birders, any pipit with obvious pink legs is a potential rarity and worthy of careful study.

First, this is a pipit and not a sparrow based on the slender, pointed bill shape. Longspurs and sparrows would have thick-based bills suitable for cracking seeds. This bird is clearly standing up tall and walking (one leg after the other), which is a behavior shown by pipits, but not by sparrows. Longspurs scurry more than they walk, and always tend to be sitting back on their haunches as they scurry across open ground. Indeed, this is a pipit.

For those that rightly checked the legs, the pink legs might have started you thinking Red-throated Pipit. The thick, dark malar area also looks unlike standard American Pipits. Back pattern is important in pipits, and this bird--with its lines of dark stripes--does not show the typical plain back of an American Pipit. However, note that the back does not have obvious pale stripes (as seen on most Red-throateds) and that the back streaking is not as strong as on a typical Red-throated. The tail is too long for Red-throated as well.

Sprague's Pipit was written in by a few people and should always be considered for pink-legged pipits in North America. Sprague's, however, has a unique appearance, with pale-edged back feathers imparting a scaly appearance, a streaked crown, and a very blank, pale buff face with a staring blackish eye. Most of the time, Sprague's are found in denser grass than this bird, which appears to be striding around on an open lawn!

So, if this has an abnormal back pattern and unusually bright pink legs, how can it be American Pipit. The answer is that it is a typical example of a 'Siberian' American Pipit (Anthus rubescens japonicus), which is available in eBird as "American Pipit (Siberian)". It is a rare but regular migrant in western Alaska and a very rare vagrant to coastal California and Baja. Key field marks are that it is like American Pipit (American) but has: 1) pinkish legs; 2) faint dark streaks on an otherwise brownish back; 3) thicker, blacker streaking on the flanks and breast, with a large triangular black malar area especially prominent; 4) generally more whitish underparts and wing edging than American Pipit.

Impressively, 18 people used the "Other" category to specify the subspecies. Congratulations--you all get extra credit!

 

THANKS AGAIN to all those that gave our quiz a try. We plan to make this a regular, seasonally-appropriate feature.

The first 25 respondents to get all answers correct will get eBird bumper stickers in the mail; the first 30 to get all answers correct were:

1. Nate Fronk
2. Mark Mizak
3. John Garrett
4. Jack Martini
5. Joshua LaCelle
6. Alex Merritt
7. Matthew O'Donnell
8. Reuven Martin
9. PERON
10. William Rockey
11. David Pereksta
12. Tim Schreckengost
13. Kimball Garrett
14. Nick Anich
15. Nathan Farnau
16. Shawn Billerman
17. nick
18. Arun Bose
19. Kyle Fritz
20. Christian Nunes
21. Matt Hysell
22. Josh Engel
23. cj white
24. Terry Hodapp
25. Amber Mooney
26. Andy Paulios
27. Michael Harvey
28. Tom Johnson
29. Samuel Galick
30. Joseph Morlan