BIRDING BY HINDSIGHT:  A Second Look at Field Notes, Part Two

Time once again to take down the old ID notebook from the shelf, dust off the cobwebs, scrape off the remains of a mosquito crushed between the pages, and revisit some of my bird identification problems and discoveries of years past.

So far, it seems the last entry on the last page (104) is from months ago: October 2000. American Pipit at Beaver Bay sewage ponds seen in good light: legs were pale, not dark! While I am somewhat surprised to see my most recent field identification discovery worth writing down is not all that recent, it’s nice to see that exclamation point. It is indeed exciting to observe something new on an old familiar species.

This observation was mentioned in passing the last time the contents of my ID notebook were discussed (see Included in this article were some various and unrelated identification entries in my notebook — i.e., things learned about in the field, not in the field guide. In this case, I had read that American Pipits can have pale legs but had never actually observed it before last October. Accordingly, here was something worth passing on to readers: that a pale-legged pipit in Minnesota is not necessarily a Sprague’s.

Part One of last year’s Hindsight article basically covered those notebook entries from 1984 through 1988; this part will bring you up to the present with a some of my entries during the past dozen years. Again, it excludes ID points mentioned in other Hindsight articles, but it probably includes information which may be discussed in greater depth in future Hindsight installments.


Churchill tour, June 1989. Heard unusual Palm Warbler song at Thompson — sounded like a Prothonotary or a loud Cape May Warbler.

Since the Palm Warbler normally gives a buzzy, rolling trill similar to a Chipping Sparrow or junco, this was definitely worth writing down. Here was a totally atypical Palm Warbler uttering clear, measured whistled notes which made it seem for a moment I was in Prothonotary-infested Mississippi River backwaters rather than in the taiga of northern Manitoba.

Actually, atypical warbler songs are encountered with some frequency, and they are often strange enough to confound even experienced listeners. Some other examples from my notebook:

Newfoundland tour, July 1989. Unusual Blackburnian song: like first half  of Golden-crowned Kinglet song — one-syllabled notes rising slightly in pitch.

Newfoundland tour, July 1992. Male Magnolia Warbler singing a perfect Common Yellowthroat song.


May 2000. A Cerulean Warbler giving a buzzy song which resembled an atypical Blue-winged or Golden-winged hybrid — I never guessed it was a Cerulean until seen.

In the first case, I thought I was aware of the many variations in Blackburnian Warbler songs, but here was one sounding like a kinglet, something I have never noted before or since. Then, three years later on the same tour, there was something even more disconcerting: a Magnolia going “witchity, witchity, witchity.” And it was embarrassing to encounter last year’s Cerulean song at Beaver Creek Valley State Park which defied my attempts to identify until the warbler finally came into view.


9/21/89. Double-crested Cormorants seen perched at 80 yards; all clearly showed a white border along the lower half of the orange pouch.

So what? Well, in the 1980s I was becoming familiar with Neotropic Cormorants in Texas, noticing how adults have a crisp white edge on their throat pouch. While this mark is distinctive, it alone is not diagnostic, as evidenced by the above notation. The difference is the Neotropic’s white edge is more clean-cut and V-shaped, and it borders a smaller and duller throat pouch. (Also, many immature/winter Neotropics lack this white edge.) By comparison, the Double-crested’s throat pouch is larger, rounded, and brighter orange, with this color also visible on its lores.

Again, you may ask, so what? Isn’t the Double-crested the only cormorant ever seen in Minnesota? Well, almost but not quite. There is one Minnesota Neotropic Cormorant record, and the species may well show up here again. So, before reporting that second state record, take a second look to make sure it’s not just a Double-crested with a white edge to its pouch.


June 1991. Red-eyed Vireo with song regularly including both an Acadian Flycatcher ‘peet seet’ phrase and a Yellow-bellied Flycatcher ’chuwee’; so close to the real things, I thought both flycatchers were there.

At the time I was in the southwestern Manitoba prairies, where neither of those Empidonax should be — at least not together at the same time. After searching in vain for any flycatchers, I gradually became aware that a nearby Red-eyed Vireo was the source of both these sounds.

And years later I was fooled by yet another Red-eyed Vireo. This one led me to think there was an invisible Eastern Phoebe nearby: May 2000, Houston Co. Red-eyed Vireo with soft, burry phoebe-like phrases; only one phrase given at a time at 10–20 second intervals.


Texas, April 1993. Immature Swainson’s Hawk has face pattern like immature Gray Hawk; underparts streaking random, not clean-cut spotting with dark malar area.

This was just one of many juvenile or sub-adult Swainson’s Hawks that have given me pause over the years. Its pale head marked only with brown lines through the eye and malar area (reminiscent of an immature Gray Hawk) was something quite new to me. Also atypical were the relatively indistinct streaks on the underparts. I was used to younger Swainson’s showing solid dark area on the sides of the neck along with rounder and cleaner spots or smudges on the underparts.

While this individual may have been in Texas, the species is present in much of Minnesota, and I submit a non-adult Swainson’s Hawk can be more confounding than almost any other Minnesota raptor. And that’s saying a lot.


Texas, February 1995. Adult Lesser Black-backed Gull seen at Mustang Island standing next to adult Herring Gull — it was at least as large or perhaps slightly larger in overall size! Was this an abnormally small female Herring and/or a very large male Lesser Black-backed?

Other than its size, the most interesting thing about this individual was its age. According to local birders, it was at least 12 years old, returning to this same beach since the early 1980s. It is tempting to suggest the old age of this gull contributed to its unusually large size (a Lesser Black-backed should look smaller than a Herring Gull), but this observation still demonstrates why gull identification can be so convoluted.

Despite the measurements given in the field guides, to separate one species of gull from another on the basis of overall size is tricky, since a male gull is often noticeably larger than a female of the same species. If you must rely on size in gull ID, it’s best to concentrate on the size/shape of the bird’s bill, head and neck — not just its overall height or length, as my notes did.


11/29/96. Unidentified duck (juv. Black Scoter?) in Grand Marais. Diving duck — never spread wings like a scoter/eider/Oldsquaw. Overall size same as adjacent goldeneyes. Bill and feet dark gray. Eye dark. Tip of bill darker/blacker like a scaup/Redhead. Inside of mouth pink/orange. Nostril half way out on bill. Base of bill at face straight, vertical — unlike an eider. Overall color solid dark brown, about like American Black Duck; a bit paler along sides with some dark smudges; no barring/spotting as on eider/Mallard. Wings plain, unmarked when seen from below as duck flapped; when preening, no white visible on primaries. Too dark overall for scaup/Redhead with no paler area at base of bill. Crown slightly darker than face (median crown stripe paler?), suggesting Black Scoter.

Here, for a change, is an entry which offers no insights about bird identification. Instead, it describes a duck whose identity remains uncertain in my mind, despite the close range and favorable viewing conditions. I still suspect it was a Black Scoter, but I’d like to think my efforts to see and describe the bird’s mouth color will prove to be the diagnostic feature clinching the ID!


Newfoundland tour, July 1997. Juvenile Common Grackle with adult at Liscombe River: standing on rock, short tail, and whitish legs/feet — suggests American Dipper!

For years there have been claims of American Dippers appearing with some regularity along fast-flowing Minnesota streams, especially on the North Shore of Lake Superior. And, indeed, there was one unequivocal record of a dipper seen and photographed here 30 years ago. I have long been skeptical of all the other reports, but at the same time I puzzled over what else could be confused with a bird as distinctive as a dipper. Then, four years ago I saw it, exclamation point and all!


12/15/97. Second-winter Ring-billed Gull with both eyes dark brown.

12/13/99. Two 2nd-winter Ring-billed Gulls seen at Canal Park: both had dark irides (both eyes) and pale pink legs.

Yep, the experts all agree. Grant’s gull identification book, the Geographic field guide, and The Sibley Guide to Birds all concur that second-winter immature Ring-billed Gulls have pale eyes and greenish legs. Hmm. (Oh, in case you’re wondering, those three gulls were indeed Ring-billeds, and they were definitely in second-winter plumage.) So, is it any wonder so many gulls present so many ID problems for so many birders?


May/June 1998. Migrant Gray-cheeked Thrush in Redwood Falls and Gray-cheeked on territory in Churchill both showed rustier tails and clear yellow/orange at bases of their bills!

It’s unfortunate the Bicknell’s Thrush is not thought to migrate through Minnesota, or anywhere near it. Otherwise, based on the criteria advanced in some identification articles, I could have added one more bird to my Minnesota list. After all, a warmer brown or rustier tail plus obvious color at the base of the bill are supposedly indicative of Bicknell’s. But in this case, the Geographic and Sibley guides do the right thing and discourage field identification of these two thrushes except when singing or on the breeding grounds. (That is, when the birds are singing and breeding, not you.)


8/15/98. Twice heard Eastern Wood-Pewees (probably fledged juveniles begging for food?) give a 1-syllabled hoarse or burry call note which could easily be mistaken for a Western Wood-Pewee; it is different, though: not as loud and not as downslurred.

The implications of this entry should be obvious enough: take a second look and listen before reporting an out-of-range Western Wood-Pewee. This would be especially true in late summer when a juvenile Eastern might be around begging for food — which is probably what I saw and heard. And note that a true Western song is indeed relatively loud and downslurred, which is similar to, but not the same as, what I heard.


Grand Texas tour, April 1999. Juvenile Loggerhead Shrikes seen with relatively narrow masks which did not extend over bill.

This was along the Gulf Coast near Houston, hardly the time or place one would suspect a Northern Shrike to occur. But this did make me aware how a juvenile Loggerhead Shrike in Minnesota in late summer might conceivably be mistaken for an out-of-season Northern. It was interesting how the shape and extent of their masks looked like a Northern’s — and it was especially disarming to see how cute a young shrike can look!


April 2000. Several Black-capped Chickadees in Worthington and one in Fairmont with alternate songs: they preceded ‘fee bee’ notes with 3–4 extra rapid whistles (softer, thinner than ‘fee bee’ notes).

Now, how could anyone possibly learn anything new about a bird as familiar as a chickadee after watching them for decades? That’s exactly what I wondered about a year ago April as I listened to those strange songs in southwestern Minnesota. This was probably just a local dialect, but why hadn’t I heard it before on previous trips here? Did chickadees anywhere else have such an atypical song? And, though it didn’t really resemble the Carolina Chickadee’s multi-syllabled song, could such a song ever be mistaken for it?


9/12/2000. Immature male Common Yellowthroat with partial black mask looks like a Kentucky Warbler — both spring and fall. Female’s combination of eye ring, brownish upperparts and yellow below, plus secretive behavior suggests Connecticut or Mourning warblers.

While I have never actually seen anyone mistake one of those immature males for a Kentucky Warbler, there is enough of a resemblance in the face pattern that I’m sure it has happened on more than one occasion. And I know the second scenario has occurred, since I was once with a group of birders who were puzzling over a female yellowthroat, trying valiantly to turn it into a Connecticut Warbler.

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At the time of this writing, I’m all packed and ready to head back to do the Newfoundland tour again tomorrow. My trusty ID notebook will be along, and there is still room on Page 104 to make some notes in case I hear some more odd Blackburnian or Magnolia songs. Or if there are any more dark, short-tailed birds standing on the rocks in a fast-flowing stream.