BIRDING BY HINDSIGHT: A Second Look at Songs (Part Three)

It wasn’t all that long ago when there was a Hindsight installment about warblers (http://mbwbirds.com/fall-warblers.html). The intention was to allay everyone’s fear of the dreaded concept of Confusing Fall Warblers, that they aren’t as bad as many birders think. But even if you still found those warblers as confounding as ever last fall, at least it’s spring now, the warblers are coming back, they’re as colorful as ever, and there’s not an ID problem in sight...right?

In sight, perhaps not. But if you plan on listening to those warblers, you will be confronted with many difficulties — enough so, that this article is devoted solely to warbler vocalizations. As mentioned in the two previous installments in this series on bird songs and calls, the intention had been for one more which would include warblers through winter finches. However, it turns out there is more than enough to discuss here on just the warblers, so there will still be a later installment on vocalizations to cover sparrows, finches, and other “post-warbler” species on the checklist.

Again, as was the case with the two earlier articles, there is little reason here to discuss vocalizations of all the species. Instead, the intention is to concentrate more on those which might be unfamiliar to even the experienced listeners and which have the most potential to be involved in misidentifications. And, unfortunately, the potential for aural misidentifications is high when dealing with warblers. Warbler songs tend to be relatively complex, the territorial song(s) of a species can accordingly be quite variable, and these individual variations within a species are often quite dissimilar to each other.

It should go without saying that an article such as this which attempts to describe in words what a bird sounds like can hardly be read in a vacuum. It will only make sense as a supplement to the actual songs you are already somewhat familiar with in the field or when used in conjunction with prerecorded songs on a cassette or CD. (And for those serious about learning warbler songs, I would recommend the recordings produced by Cornell, “Songs of the Warblers of North America” by Donald Borror and William Gunn.) Keep in mind, however, that listening to tapes is no substitute for field experience. In many cases, your best aids for identifying a song include habitat, geographic location, and time of year, and these are not found on a tape.

There are two other initial thoughts to keep in mind as you sort through warbler songs and attempt to actually see what you’re hearing to confirm your identifications. First, many of those warblers you see with relative ease in May actively flitting through the vegetation will be sitting relatively still when singing on territory. Accordingly, you will find most singing male warblers harder to spot in June than they were when moving around and catching your eye during migration.

And second, once you’re sure you hear an Ovenbird, Northern Waterthrush, Connecticut or Mourning warbler and you want to see it, look up not down. While such species may stay on or close to the ground in migration, on their breeding grounds they often sing perched in a tree dozens of feet above the ground.

Singing the Golden-winged Warbler Blues

It is common knowledge among birders with even limited experience at warbler watching that Blue-winged and Golden-winged warblers widely hybridize. What is less generally known, however, is that the plumages of these hybrids are quite variable, and they frequently do not match what the standard field guides conveniently label as “Brewster’s” and “Lawrence’s” warblers. (But all that would be the subject of another article entirely.)

More to the point here is that the songs of these hybrids are probably as variable as their plumages, and even what looks like a “pure” Blue-winged or Golden-winged can sing an atypical song. Therefore, while Blue-wingeds and Golden-wingeds are supposed to say “beee bzzzz” and “bee bzz bzz bzz” respectively, they — and their hybrids — just might sing something more complicated and quite different from their standard songs. Nor would it be surprising to hear a Blue-winged sing a Golden-winged song, or vice versa.

Any attempt to describe all those possible song variations would be quite beyond the scope of this series of articles. The point to remember is if you hear, for example, what sounds like a Blue-winged in northern Minnesota, it would be necessary to actually see it to make sure it isn’t a hybrid or Golden-winged with an odd song. Similarly, if you hear a buzzy song which sounds like a Prairie Warbler (or, say, a Cerulean in northern Minnesota), be sure to track it down to preclude the possibility of a Blue-winged or Golden-winged warbler singing an atypical song.

(And I still remember that song I clearly heard some 25 years ago in an Arkansas swamp which exactly matched the tape I had with me of the Bachman’s Warbler! I suspect it was actually one of those variant songs of a migrating Blue-winged or Golden-winged, but to this day I still wonder. . .)

Nashville, Tennessee 90210

Yes, I realize the name of the TV show is actually “Beverly Hills 90210”, but over the years I have heard so many birders claim how hard it is to distinguish the songs of Nashville and Tennessee warblers, that all this fuss could almost be the premise for another soap opera. However, any similarity in the songs of these two warblers is about as superficial as any soap opera.

Only on rare occasions have I heard a distant song which made me wonder momentarily whether it was a Nashville or Tennessee. But the operative word here is “momentarily”, and it only took a second listen to figure out which one it was. The two-part pattern of the Nashville’s song may somewhat suggest that of the Tennessee, but the latter warbler’s song is actually different: louder, sharper, more strongly accented, and typically three-parted.

But there actually is a Minnesota warbler with a variable song which often ends up sounding very much like a Nashville: the Yellow-rumped. This ubiquitous bird may be all too familiar to warbler watchers, but I am quite sure that most birders are quite unfamiliar with its song variations. Its colorless song isn’t much to begin with, and one of its frequent variations is a two-parted song which closely resembles the “seebit seebit seebit ti ti ti ti ti” of the Nashville Warbler. The only difference to my ear is this Yellow-rumped variation seems a bit slower and “looser” than the Nashville’s song.

Give Me a Buzz Anytime

Another frequent song variation in Yellow-rumped Warblers involves some buzzy notes at the end of the song, although such a song still sounds more like a Yellow-rumped than anything else. That aside, however, I’ve always liked those warblers with buzzy songs: Blue-wingeds, Golden-wingeds, Black-throated Blues, and Ceruleans are decidedly uncommon or local; the Prairie Warbler is a genuine rarity in Minnesota; while the more widespread Northern Parula and Black-throated Green are especially striking in appearance.

Unfortunately, in addition to the difficulties already discussed involving the Blue-winged’s and Golden-winged’s songs, other buzzing warbler songs present some additional identification problems:

• At a distance, one of the Northern Parula’s songs (the multi-syllabled one with notes preceding the prolonged buzz) can sound much like the fast variation of a Black-throated Blue Warbler song (and this faster Black-throated Blue song is probably unfamiliar to most birders). Further, this parula song sounds very much like the Cerulean Warbler’s: the main difference is that the very end of the parula’s song typically drops off abruptly in pitch. This abrupt ending is not always audible, however, but parulas and Ceruleans are generally not found singing in the same places, so you can usually determine what you’re hearing by where you are.

• Speaking of Black-throated Blues, there is a common misconception that it simply sounds like a slow Black-throated Green. In reality, one Black-throated Green song (“zee zee zoo zoo zee”) is just as slow as an average Black-throated Blue song, and, consequently, it can easily be misidentified as the latter warbler. (Think twice before claiming to hear a Black-throated Blue in summer if you’re anywhere in Minnesota other than in Lake or Cook county.) The difference is that all the notes preceding the final higher-pitched note in any Black-throated Blue song are on the same pitch (“zur zur zur zee”); in the slow Black-throated Green song, the pitch of the first, second and fifth notes is higher than the third and fourth.

Not all Yellow Warblers are Yellow

Even though Yellow Warblers commonly nest – and consequently sing – throughout Minnesota, it is disconcerting how difficult it is to recognize this warbler’s song much of the time. While its most recognizable song can be transcribed as “sweet sweet sweet sweet ti ti ti ti sweet”, this species also gives a lot of nondescript variations of its primary song which lack any clear patterns and defy simple transcriptions. Indeed, I would consider the songs of this widespread species to be among the most difficult ones to learn. (In many cases, I end up relying on habitat and geographic location more than anything when identifying Yellow Warbler songs.)

Some Yellow Warblers end up sounding very much like Chestnut-sideds, and many birders are unaware Chestnut-sideds often give a nondescript Yellow-like song which lacks the normally characteristic, abrupt, lower-pitched ending.

Other Yellow Warblers can sound like a Magnolia (which, in turn, sound a lot like the rare and local Hooded Warbler), some sound like American Redstarts, some like Wilson’s, and still others almost sound like Canadas (which, in turn, can sound like Magnolias when they fail to begin their song with their characteristic chip).

So, how does one separate such relatively nondescript, patternless songs? Not by reading this article, unfortunately. Learning bird songs is just plain difficult, and it can be argued that warbler songs are the most difficult of all. As mentioned earlier, the written word is hardly the best medium for describing sounds, which are best learned by hearing them in the field or possibly on tape. In some cases, I admit this article will be unable to offer solutions to ID problems. The best it can do is call attention to those songs where there are special difficulties and potential for misidentifications so the reader can at least be prepared.

(Having said all that, however, I now plunge forward with still more problems!)

Highly Confusing Songs

As our hearing abilities decline with age, the bird sounds that are typically lost first are those of the higher pitches. In a way, perhaps, this could almost be something frustrated warbler listeners may look forward to, since some of the most confusing warbler songs are those with the highest frequencies. After all, you can’t misidentify what you cannot hear!

All kidding aside, it takes a lot of concentration and practice to distinguish the high-pitched warbler songs, especially those of the Cape May, Blackburnian, Bay-breasted, Blackpoll, and Black-and-white. The previous article in this series on song identification (http://mbwbirds.com/songs-ii.html) has already mentioned the potential for mistaking the Golden-crowned Kinglet song for that of a Cape May, and there are other difficulties to be aware of when listening to such high-frequency sounds:

• Besides that kinglet, the Cape May Warbler can easily be mistaken for a Bay-breasted when it gives its alternate two-syllabled “seetsee seetsee seetsee” song. This song is so close to the Bay-breasted’s that there have been times when I was unable to tell with any confidence which warbler I was hearing. Similarly, a weak or distant song from an American Redstart or Black-and-white Warbler can strongly resemble this two-syllabled Cape May/Bay-breasted song. I would suggest, therefore, that before you claim a heard-only Bay-breasted (especially in summer, since breeding Bay-breasteds are relatively local and rare in Minnesota), it would be wise to preclude those other three warblers as possibilities.

• Speaking of the Black-and-white Warbler, its song often sounds more one-syllabled than two, even at close range, and can then be easily mistaken for the primary Cape May song (“seet seet seet seet seet”).

• Another high-pitched singer, the Blackpoll Warbler, was actually the first bird whose song eluded Roger Peterson’s aging ears. (Really – I’m not making this up: it was in Churchill in June 1985.) If you can hear it, though, the standard Blackpoll song is not that difficult to identify, although I have heard some Blackpolls with slower, shorter, and louder songs which sounded very much like Cape Mays. And I once heard a Blackpoll run its notes together into a fast, buzzy trill and sound like a Worm-eating Warbler.

• And then there’s the Blackburnian, almost everyone’s choice for best-looking warbler. It’s not mine, though, perhaps because it has too many song variations. The usual perception is that the Blackburnian always ends its songs with a distinctively thin and rising high-pitched note, but there are times this note is either not given or not audible. (And I vote for “not given” over “not audible”; I’m not yet ready to admit I’m old enough for the latter to be true!) When this diagnostic note is not heard, the Blackburnian can sound like any number of warblers, including the Nashville, Yellow, Yellow-rumped, Black-and-white, or Wilson’s.

• Actually, the most common Blackburnian song heard in Minnesota definitely lacks any distinctive high-pitched note at the end. Instead, listen for a high, thin, somewhat Cape May-like “tsss-sah tsss-sah tsss-sah” song, with these two-syllabled notes having a diagnostic lisping quality, which, to my ear, sounds unique.

The Trill is Gone

In winter, at least, the trills are indeed gone. But with the arrival of spring all those dreaded trill songs of the warblers and other birds return, and — with apologies to B. B. King and his classic song — it’s almost enough to make you want to sing the blues. In my opinion, those songs which can be described as a trill are by far the most difficult ones to distinguish. Among the warblers, these include the Orange-crowned, Pine, Palm, Worm-eating, and Wilson’s, while Dark-eyed Juncos, Chipping and Swamp sparrows do their part to add to the confusion.

There would be much less confusion if all these species confined themselves to their normal songs without variation, but they all frequently vary their songs enough to closely resemble one or more of the other species:

• A typical Orange-crowned Warbler song is a distinctive two-part trill, with the second part shorter and lower-pitched than the first. It is then unlike the typical Wilson’s Warbler trill which is usually all on one pitch. (Or the Wilson's final note sometimes drops in pitch, but then its song is easier to recognize.) One problem is I have frequently heard these two warblers sing each other’s primary song and then sound essentially indistinguishable. Another problem is that the one-pitched version of these two warblers’ songs can often resemble some Palm Warblers and some Swamp Sparrows.

• The normal song of the Pine Warbler is probably the most easily recognized of this group: it sounds slower and shorter than most of the others with a gradual increase in volume at the end. Unfortunately, this warbler can also sing a faster trill and then closely resemble a Dark-eyed Junco or Chipping Sparrow song.

• The most characteristic Palm Warbler song is usually safe to distinguish from the others due to its buzzy quality and “rolling” trill of notes which rise and fall in pitch. It’s hardly always that easy, though. As mentioned earlier, some Palms sound quite similar to Orange-crowned and Wilson’s warblers or to Swamp Sparrows, while other Palm Warblers can sound almost identical to juncos and Chipping Sparrows.

• A Worm-eating Warbler supposedly sounds thinner and buzzier than the Chipping Sparrow, and on the average it probably does. But more than once in Minnesota I’ve heard what sounded like a perfect Worm-eating song and ended up tracking down a singing Chipping Sparrow instead.

• Since the Dark-eyed Junco is one of Minnesota’s most common migrants, and since it frequently sings in spring, its trill with its usually distinctive “ringing” quality might be the best place to begin listening. Or perhaps you’d find the normally dry, rattling trill of the ubiquitous Chipping Sparrow easier to master. Other birders might find the Swamp Sparrow’s typically slower song easier to practice on, since this species’ habitat alone often indicates its identity.

Of course, none of these birds is a warbler, but each of them can sufficiently alter its song enough to sound like one. For example, juncos can be confused with Palms or Pines; Chippings can also be mistaken for these two (or, as mentioned above, a Worm-eating); and Swamp Sparrow songs can resemble those of the Orange-crowned, Palm, and Wilson’s.

Call Notes of Note

If you’ve managed to read this far, the difficulties involved in identifying warbler songs should be abundantly obvious. However, believe it or not, learning warbler vocalizations can get even far more challenging: all you have to do is venture beyond songs into the realm of call notes. Rest assured, though, that this section will be brief for two reasons. First, call notes lend themselves to written transcriptions even less than songs. And, second, I readily admit there are a lot of warblers whose call notes I have yet to recognize with any consistent confidence.

But attempting to learn at least some call notes is definitely worth the effort and within the grasp of even the casual birder. Start with the “check” note of the Yellow-rumped Warbler: you’ll hear it almost everywhere and thus have plenty of practice with it. The harsh and distinctive “tshh” of the widespread Common Yellowthroat is also relatively easy to learn. Equally prevalent in many places is the loud and sharp Yellow Warbler call note, while in other places the equally loud and sharp “chink” of the Northern Waterthrush is even more recognizable. And that curious and unique call note of the Magnolia is quite unlike any other warbler and hard to forget: somehow this “false” note simultaneously resembles those of a Cliff Swallow, Hermit Thrush, and Bobolink.

If you really want to impress your birding friends, it doesn’t take long to learn the distinctive and hollow call note of the Mourning Warbler (it has a close resemblance to the Wilson’s note and is vaguely reminiscent of a yellowthroat note). Once you do, you’ll find this highly sought warbler is actually one of the most common breeding warblers in northern Minnesota. A bigger challenge would be to learn the rich, liquid “pwit” or “squeet” of the similar Connecticut Warbler. This is not because it’s rare (in some places Connecticuts are more common than Mournings), but simply because they seldom utter their call note.

If you want to pursue the subject of call notes further, there is an article worth looking at in the June 1996 issue of Birding (25:159–168): “Call-Notes of North American Wood Warblers” by Stephen Getty.

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Had enough? Still confused? Even more confused than before you read any of this? That’s OK. Learning warbler songs is rewarding, but it’s not for everyone. There’s not a thing wrong with just watching warblers this spring and enjoying what they look like. If you find warbler songs more frustrating than fun, feel free to simply tune them out.