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Category: Begging calls

Bohemian Rhapsody

Bohemian Rhapsody

Bohemian Waxwing2014-7-10-2_m
Bohemian Waxwing, Nabesna Road, Alaska. These chicks were approximately 10-12 days old when this photo was taken, and weren’t shy about making some noise! © Andrew Spencer.

I can still remember the first time I saw a waxwing.  I had only been birding for a year or two, and I had already picked out Cedar Waxwing as one of my most wanted birds.  I was six at the time, and I did most of my birding with my grandmother, either on Long Island (where I lived at the time) or in western Massachusetts (where she had her house).  We had searched for waxwings several times, to no avail, so I was overjoyed when I first laid eyes on them.

It took far longer for me to come to grips with their larger cousins, Bohemian Waxwing.  By then I knew enough to pay attention to how birds sounded, and I can still remember the high-pitched, tinkling trill they let out, so different from Cedars.  And then that was all I ever heard from them, every time I saw one.  It’s a gorgeous sound from a gorgeous bird, but would it hurt for them to throw a little variation in?  It turns out that waxwings have some of the simplest repertoires of all passerines, with no true “song”, or at least none that has been documented.  And even their calls are typically variations on the same trill.

Or so I thought.  This past summer I was privileged to be able to spend a lot of time recording in the far northern parts of North America.  Among the many species I was hoping to target was Bohemian Waxwing, on the vague theory that they must have more than just that trill call, and if they did I would be most likely to hear it on the breeding grounds.  At first I was rather frustrated.  I found waxwings aplenty, but they just would not cooperate!  Unlike in those big, practically tame flocks I was used to from irruption years in Colorado, Bohemian Waxwings in the taiga were quiet, shy, and rarely in groups larger than three or four birds.

But then I lucked out.  I was driving along the Nabesna Road in eastern Alaska when I heard the distinctive trill of a Bohemian Waxwing out the window.  I worked my way into the stunted black spruce muskeg and was rather surprised when I found a pair of birds that were much less shy than I had come to expect.  The reason why became apparent a short while later when I saw one of the birds carrying nesting material to a spruce tree.  “Here it is,” I thought, “my chance to record some different vocalizations!”  And with that in mind I stood behind a nearby spruce and trained my mic on the birds as they built their nest.  But as I sat their recording them I was more and more disappointed – they occasionally gave either long or short versions of their normal trill, but nothing different.  It wasn’t until I listened to a cut I made where both birds landed together at the nest site that I heard a barely audible, amazingly variable sound unlike any I’d ever heard from Bohemian Waxwings before.  Jackpot!  That eureka moment recording (and a photo of the bird making it) are linked below:

Bohemian Waxwing2014-6-10-1_blog
Bohemian Waxwing, Nabesna Road, Alaska. © Andrew Spencer.

I then carefully snuck out of the bog. I was going to pass by the Nabesna Road again in about a month, and I had the perfect setup waiting for me.  If (and it’s always a big if with nesting birds) the pair of waxwings didn’t abandon the nest, and nothing predated the young, I’d have a “captive audience” on my return trip to see what else waxwings can say.

From that first observation of the pair I noticed several things.  First, the birds had both very short (only a few notes) and more normal long versions of their trills, and they seemed to serve different functions.  The long trills, what I consider the classic Bohemian Waxwing call, were typically given at long intervals and most often when a bird took off from an exposed perch.  The short trills, on the other hand, were given much more frequently, often by a bird perched prominently on a spruce tree, both when the other member of the pair was present and when it had flown off.  Playback of the long call either elicited no response, or the bird flew away, whereas the short call would bring the bird in close, and at times even low.  My suspicion is that the short call serves some kind of territorial purpose, but even after watching the birds for a long while I am not entirely sure.  Examples of both the long calls and short calls are here:

Fast forward a month, and I was back on the Nabesna Road.  I was ecstatic to find that the nest was still there, and four well-feathered young were looking healthy and alert in it!  Before I even got into position to record the nest I got a good recording of another, completely different vocalization – a very high-pitched, clear, descending whistle, very much like the “seer” call of a thrush.  This was clearly an alarm call, given at my presence, though the birds quickly calmed down and resumed their normal behavior.  I was beginning to wonder if that’s all the waxwings would do in alarm when a passing band of Gray Jays decided to drop in.  Boy did the waxwings take offense at that!  One of the birds outdid itself in driving off the offending jays, giving two more alarm calls while at it.  The first, given only twice an apparently in extreme alarm, was a harsh, low-pitched growl.  This was quickly followed by short trills that, while higher-pitched than the growl call, were significantly lower-pitched than their normal trills.  Some loud bill snapping was also thrown into the mix, making for quite the varied repertoire of alarm sounds!  You can hear both the clear whistle call and the other alarm sounds below:

Once everything had returned to normal I took the opportunity to record the young begging.  Compared to the alarm calls the adults gave these calls were rather boring, essentially just a noisy version of the adult trills.  That recording is linked below:

The time I spent with Bohemian Waxwings this past summer was near the top of my list of highlights for my trip to Alaska.  But even with everything I recorded from them, I think there is still more to be captured.  A few winters ago my friend Ian Davies heard what may actually be a stereotyped song from the species (something that has never been described or recorded) that:

“sounded almost like the pattern of a White-winged Crossbill song but with the calls of a Bohemian Waxwing…a longer sustained note of the standard musical rolling note, on one pitch, for maybe 1-1.5s, and then changing without stopping to another pitch, all of this with the standard clipped musical quality”

So there’s clearly more to discover about waxwings – a chance for anyone with a mic, or even an iPhone, to document something new if they’re in the right place at the right time!

What’s That Screeching?

What’s That Screeching?

Independent young Great Horned Owl, Louviers, Colorado, 5/26/2008. Photo by Thomas Halverstadt (Creative Commons 2.0).
Barn Owl, Herefordshire, England, 8/16/2006. Photo by Stevie-B (Creative Commons 2.0).

Around this time of year, I tend to get a lot of questions from people who want to know what kind of bird might make frequent loud harsh screeches at dawn, at dusk, or in the middle of the night.  In most of the cases I’ve been able to solve, the culprit has turned out to be a young Great Horned Owl — one of the most vocal youngsters in the avian world (though one of the least vocally skilled, if I may be so bold as to say so).

However, back when I first started tracking these screeches to their source, I was usually hoping for a Barn Owl.  And in areas where both species are possible, I think that a number of birders may regularly misidentify the shrieks of young Great Horneds with the “shhhhk!”  of the Barn Owl.  Thus, it seemed like a good idea to post on how to tell these two (rather unpleasant) sounds apart.

Great Horned Owl

I tend to associate the shriek of Great Horned Owl with young birds, but according to the BNA account, it can also be given by adult males and, especially, adult females.  Juveniles shriek while still in the nest, and continue shrieking on a regular basis until at least December or January.  The shriek is usually short (half a second or less), typically slurred either up or down, and almost always sounds at least partially squeaky (as evidenced by the banding on the spectrograms):

Presumed juvenile Great Horned Owl, Walla Walla County, WA, 8/20/1990. Recording by Dave Herr.

(Click here to listen to the above recording at the Macaulay Library.)

The above recording is typical in that the sound is mostly noisy, but partly voiced — in this case, even slightly polyphonic.  The end result is a call that sounds like an inhaled hoarse scream.

Here’s a fairly similar example, from a bird still in the nest (with a Say’s Phoebe in the background):

Great Horned Owl juvenile begging from nest, Baca County, CO, 4/23/2005.

Meanwhile, the following recording helps demonstrate how variable this vocalization can be, even within individuals.  It was recorded from a bird that appeared to be an adult, though given the late date it may have been a first-year bird that had recently acquired adult plumage.

Great Horned Owl, Minnehaha County, SD, 9/2/2007.

Besides being strongly upslurred instead of downslurred, these calls (particularly the first one) are also less noisy, dominated by bands on the spectrogram, giving them a tone quality that is squeakier and less like television static.  The “squeaky” quality and the strong inflection are two of the best ways to tell a Great Horned Owl from a Barn Owl.

Barn Owl

Although Barn Owl vocalizations are just as variable as those of Great Horneds, the “classic” Barn Owl screech is fairly distinctive: longer than a Great Horned shriek (up to a second long or more), and consisting mostly of noise, neither upslurred nor downslurred, perfectly horizontal on the spectrogram and very lightly banded, if at all.  The call may sound like loud television static that is abruptly turned on and then off.

Barn Owl, San Joaquin County, CA, 5/13/1990. Recording by Geoff Keller.

(Click here to listen to the above recording at the Macaulay Library.)

Note that each call above ends with a very brief squeak, distinctly audible in this close-range recording.  Many Barn Owls, but by no means all, sound this way.  Here’s an example of shorter calls devoid of squeaks:

Two Barn Owls, Miami-Dade County, FL, 12/28/2004. Recording by Gerrit Vyn.

(Click here to listen to the above recording at the Macaulay Library.)

As always, we should beware individual, geographic, and age-related variation when identifying owl shrieks.  Here’s a bird from Ecuador that sounds much higher-pitched and distinctly upslurred.  It still has the hissing, non-squeaky tone quality typical of the species, but if such a bird were to vocalize in North America, it would make identification somewhat more challenging:

I hope this post is helpful for those wishing to make sense of the shrieks they’ve been hearing in the night.
What We Don’t Know About Bird Sounds

What We Don’t Know About Bird Sounds

A while back I mentioned my long-standing desire to post a list of things we don’t know about North American bird sounds, with an emphasis on the simple questions that amateur sound recordists could answer.  I’ve finally decided to take a crack at it.

Below, you’ll find my first attempt to list some things we don’t know.  It’s not even close to an exhaustive list, nor is it necessarily up-to-date — it’s merely a teaser, mostly based on a quick perusal of a few select BNA accountsMy whole purpose is to inspire some amateur research projects. Most of these are questions that amateurs can answer in whole or in part.  You might be surprised at what you could contribute to science with a little time and energy.

Song Repertoire

How many different songs can one male bird sing?  This question can be easily answered by simply recording singing individuals for an extended period. The answer is sometimes quite different even between closely related species, or within populations of a single species.  Here are some birds whose song repertoires are poorly known.

  • Northern Shrike
  • Loggerhead Shrike
  • Mountain Bluebird
  • Virginia’s Warbler
  • Black-and-white Warbler
  • Hepatic Tanager
  • Lark Sparrow
  • Dickcissel
  • Orchard Oriole

Begging Calls

An easy way to contribute is to record the sounds of young birds, either in the nest or out of it.  Ideally, locate a nest and monitor it, noting the dates of hatching and fledging, and making recordings on a regular basis in between, to document the development of the sounds.

  • Mountain Bluebird
  • Lucy’s Warbler
  • Dickcissel
  • Blue Grosbeak
  • Spotted Towhee

Geographic Variation

Birds in this category may sound different in different parts of their range.  Some of these differences may have taxonomic implications.  On the other hand, some of these birds may not sound much different across their ranges; we don’t really know.

  • Cave Swallow
  • Curve-billed Thrasher
  • Spotted Towhee (calls)
  • Great-tailed Grackle

Call Repertoire

The birds in this category may make sounds that do not appear on commercially available bird sound recordings and are poorly described in the scientific literature.  To solve the problem, we need recordings of all the sounds birds make — not just the pretty ones, or the loud ones — plus detailed notes on the behavioral context of the sounds: what was the bird doing when it made the sound?  What time of year and day was it?  What was the bird’s age and sex?  And so forth.

  • Clark’s Grebe
  • Common Moorhen
  • Olive-sided Flycatcher
  • Greater Pewee
  • Loggerhead Shrike
  • Blue Grosbeak
  • Vesper Sparrow
  • American Tree Sparrow (more on this in an upcoming post)
  • Pine Siskin
  • Bullock’s Oriole

Spectrographic Analysis

Many vocalizations have been described in the literature only phonetically, and it can be difficult to determine which call the author was hearing — or which one you are hearing — unless you have spectrograms to compare.  These species could use a formal description of repertoire with spectrograms:

  • Northern Shrike
  • Phainopepla
  • Common Myna
  • Bewick’s Wren (calls)
  • Rock Wren
  • Hepatic Tanager
  • Summer Tanager
  • Lark Sparrow

Flight Calls

Not enough flight calls have been recorded from these species (during the daytime) to determine the limits of variation in the sounds they might make during nocturnal migration.

  • MacGillivray’s Warbler
  • Western Tanager
  • Black-headed Grosbeak
  • Brewer’s Sparrow
  • Western Meadowlark

Other Questions

  • Goldfinches (at least Lawrence’s and Lesser, and probably American also) apparently sing two types of songs: a long, continuous one and a disjointed one that sounds like a long string of calls.  The two song types grade into one another.  The disjointed song has never been described in the literature and its purpose and behavioral context remain unknown.
  • Male Painted Buntings may continue learning new songs after their first year of breeding; extensive recordings of the same individual across multiple years would help resolve the question.
  • The BNA account on Bullock’s Oriole says that “Males seem to sing only a single song,” but I suspect the situation is much more complex, as it is in the closely related Baltimore Oriole.  Shall we find out?

And that, folks, is just what I found in a perusal of roughly 50 BNA accounts.  This is just scratching the surface.  Note how many common and widespread species are on the above lists.  Everybody in North America can contribute if they’ve got the time — and especially if they have recording equipment.

If you’ve got anything to add to this list, post it in a comment!  I’ll try to get a master list put together eventually.

Murder Most Foul

Murder Most Foul

Eleventh of May, 2009, just before 11 AM: I was walking down the road in upper Carr Canyon in the Huachuca Mountains of Arizona, hoping to find something interesting to record.  A Dusky-capped Flycatcher was calling occasionally; some distant Yellow-eyed Juncos and Western Tanagers were singing; but the day was beginning to heat up, and bird activity was waning.  Near where I parked my car, I heard some quiet high-pitched squeals, but they didn’t seem to belong to anything in particular.  For a moment I got excited when a pair of Buff-breasted Flycatchers drove off a pair of Brown-headed Cowbirds that had been, I guessed, “casing the joint” — but this interaction was brief and quiet and I got none of it on tape; nor could I find the flycatchers’ nest.

A minute later, from back near my car, I noted that high-pitched squealing again.  Belatedly, I realized it sounded like nestlings.  Eager to record some begging calls, I headed for the sound, which was coming from near the top of a short oak, and turned on my microphone.

At first it just sounded like baby birds being fed:

Carr Canyon, AZ, 5/11/2009.
Carr Canyon, AZ, 5/11/2009.

But soon it became clear that something else was going on.  There was more activity in the tree than you’d expect from parents feeding nestlings — at least two or three birds were fluttering agitatedly in the crown, but I couldn’t see what kind they were, or what exactly they were doing.  It started to sound less like begging calls and more like distress calls:

Same as above.
Same as above.

And then, suddenly, a large dark bird took off from the tree with something dangling from its bill.  Behind it came a smaller bird in hot pursuit:

Same as above.
Same as above.

The birds landed in the open for a moment, long enough for me to see that the nest robber was a male Brown-headed Cowbird, and the frantic parent a Hutton’s Vireo.  Then the cowbird took off with the nestling and the Hutton’s went after it, far out of my sight.

But the squealing at the nest continued.  After a moment I risked walking towards it, and discovered the female cowbird pecking furiously at the contents of the nest, while another Hutton’s Vireo, or the same one, flitted around it and scolded it ineffectually:

Hutton's Vireo adult scolds and nestling distress calls during predation by Brown-headed Cowbird.  Same recording as above.
Hutton's Vireo adult scolds and nestling distress calls during nest predation by Brown-headed Cowbird. Same recording as above.

Within a couple of minutes, the squeals stopped, and I could see the female cowbird eating something out of the nest.  After another minute she fled the scene, leaving the adult vireo alone with the ruined nest, and me as a witness to a particularly brutal version of a very rare event.

It has long been known that Brown-headed Cowbirds will occasionally destroy the eggs of their host species instead of parasitizing the nest.  It is rarer for cowbirds to attack nests after the eggs have hatched, but even so, the removal of nestlings by cowbirds has been documented one or two dozen times in the literature.  In some of these cases, the cowbirds have been seen to eat the nestlings.  However, the vast majority of all such attacks have involved solo females.  In only two or three cases has nest predation involving male cowbirds ever been documented (see Igl 2003 and the references cited therein).

Why do cowbirds do this?  One fascinating line of thinking is the “mafia hypothesis,” which holds that cowbirds come back frequently to check on the eggs they have laid in other species’ nests — and if they find the cowbird egg has gone missing (presumably because the host parents have recognized it as an imposter and ejected it), the cowbirds destroy the nest in retaliation (Hoover & Robinson 2007).  By forcing the host parents to build a new nest, the cowbirds may be giving themselves another chance to parasitize it at a later date.

I can’t comment on the validity of the mafia hypothesis, but I can say that what I witnessed was fascinating, and a little disturbing — and yet another reason to follow up on odd, unidentified squeaks in the forest.

The Fall Challenge

The Fall Challenge

I’ve noticed that an awful lot of nature sound recordists in North America have traditionally focused on recording in the spring and early summer.  If you browse the Macaulay Library catalog, or the Borror Lab‘s recordings, or Xeno-Canto‘s North American collection, you’ll see exactly what I mean.  The vast majority of recordings are made from April to June, with a fair number from March and July as well.  Late winter (January-February) is an underrepresented period, but it pales in comparison to the period from August to December, when it seems like almost nobody goes out with a microphone.

We’re heading into that traditional “dead period” now, and I just want to point out that no matter where you live, there are some terrific opportunities for recording (and listening to)  some of the most interesting and worthwhile bird sounds of the entire year!  For example:

  1. Begging calls, begging calls, begging calls. I said it thrice because I believe it’s one of the most shamefully neglected classes of bird vocalization, and the Fledgling Project agrees with me.  You won’t have to browse many Birds of North America “Sounds” accounts before finding the phrase, “development not described.”  That’s because not enough microphones have been pointed at squalling baby birds, whether in or out of the nest.  This is one of the easiest ways for an amateur recordist to make a big contribution to our knowledge of birds.
  2. Juvenile subsong. In many species of bird, youngsters have already started to practice their songs, in a developmental process akin to the “babbling” of human babies.  The results can be fascinating, beautiful, and scientifically significant.
  3. Shorebird calls. Millions of shorebirds are headed south right now throughout North America, and some of them will still be southbound as late as October.  Shorebirds are traditionally pretty poorly represented in audio collections, but there is a lot to learn about their calls also.
  4. Fall song. Some birds can occasionally sing as much on fall migration as they do on spring migration, or even more, with vireos being a great example.  Phoebes and other flycatchers can occasionally give variable renditions in fall of their typically stereotyped spring songs.  How and why does fall singing differ from  spring singing?  More recordings would help answer the question.
  5. Nocturnal flight calls of fall migrants. Many people have jumped on this bandwagon in the East in recent years, and some are starting to do so in the West — in fact, in just two weeks I’ll be co-leading a workshop on nocturnal migration here in Colorado that filled up some time ago.  I know people in several states who have just begun putting microphones out to capture the sounds of the overnight flight, and there are a lot of online resources to help people get involved.  Start with, the website of Bill Evans*, one of the original flight call gurus, where you can listen to flight calls online and learn how to build your own cheap nocturnal sky microphone. You can hear more flight calls from the East on the websites of Steve Kelling., A.P. Martin, and Matt Orsie,  and get updates on western nocturnal migration by following Ted Floyd on Twitter.
  6. Winter specialties. Crossbills, juncos, American Tree Sparrows, Evening Grosbeaks, redpolls, longspurs, Snow Buntings, swans, geese, gulls, ducks.  And crossbills.  Need I say more?

If you already record sounds, don’t leave your microphone at home in the bottom half of the year!  Recordings from fall and winter are rarer, and therefore more valuable.  And if you don’t yet record, but have the wherewithal to start, now’s a great time!

*revision 8/18/2009: thanks to Ted Floyd for pointing out to me that is Bill Evans’s website, not Michael O’Brien’s.

A Brown-headed Stepchild

A Brown-headed Stepchild

Last weekend in Minnesota I observed a juvenile Brown-headed Cowbird (Molothrus ater) being fed by a much smaller adult Chipping Sparrow (Spizella passerina).  I’ve known for years that cowbirds are brood parasites, which means they lay their eggs in other birds’ nests and leave the job of child-rearing to unwitting foster parents.  But this was the first time I’d actually seen it, and heard the cowbird’s begging calls:

Begging calls of a fledgling Brown-headed Cowbird, Murphy-Hanrehan Regional Park, Savage, MN, 7/6/2009 (19-45).
Begging calls of a fledgling Brown-headed Cowbird, Murphy-Hanrehan Park Reserve, Savage, MN, 7/6/2009 (19-45).

Full disclosure: I didn’t actually record the Chipping Sparrow’s foster child; the above recording was made the following day, when I chanced upon another fledgling cowbird, this one being fed in underbrush by a parent I never identified.

Hearing two begging cowbirds in two days got me thinking.  How important are begging calls to parent birds?  What if the begging of the cowbird sounds nothing like the begging of its foster parents’ biological chicks?  Is it less likely to be fed?

Because brood parasitism is such a fascinating phenomenon, one with significant implications for both evolutionary theory and for endangered species management, it has been extensively studied.  Some brood parasites apparently mimic their host species in both sight and sound, presumably so that the foster parents will be more likely to accept them, but according to Lorenzana & Sealy (1996), Brown-headed Cowbirds do not do this.  Over 140 bird species have been known to successfully raise Brown-headed Cowbird chicks, but those chicks always sound like typical cowbirds.

As the Fledgling Project makes clear, baby birds of different species can sound completely different.  Therefore, it would seem that parents who respond preferentially to chicks of their own species would have an evolutionary advantage over those who respond willingly to cowbird chicks.  It’s been shown that the begging of cowbird chicks tends to be both louder and more frequent than the begging of their non-cowbird nestmates, and it’s been suggested that having a cowbird chick in the nest makes the nestmates change their calls in response, but as far as I can tell, researchers haven’t yet directly tackled the question of differential parental response to Brown-headed Cowbird chicks based on their vocalizations.

Anyone looking for a research project?

Beware the Bendire’s

Beware the Bendire’s

In the middle of the afternoon a few weeks ago I was sitting in the public library in Sierra Vista, Arizona–a wonderful facility, by the way–escaping the heat of the day to download my bird sound recordings, recharge my batteries, and check my email, when my attention was drawn to a bird hopping directly toward me on the ground.  No, it wasn’t in the library–it was on the other side of the floor-to-ceiling plate-glass windows, out in the desert garden.  But it might as well have been in the library, because it ended up hopping right up to the window, less than four feet from my face, so that even without binoculars I could clearly see its pale yellow eye, its short, almost straight bill, its nearly-unmarked breast with a few spots front and center…in short, every field mark necessary to confirm its identity as a Bendire’s Thrasher–a scarce species I had seen only three times before.

And then, through the window, I heard it begin to call: a slightly noisy, one-syllabled note reminiscent of the “cheep” call of the American Robin.  Naturally, I raced right out to record it:


The call note clinched the ID.  It was completely different from the characteristic call of the very similar-looking Curve-billed Thrasher, the loud wit-weet! that is a trademark sound of the southwestern deserts:

Curve-billed Thrasher call. Catalina State Park, Arizona, 2/23/2008 (08-19).
Curve-billed Thrasher call. Catalina State Park, Arizona, 2/23/2008 (08-19).

I was particularly excited to record the Bendire’s because their one-syllabled call note had been described in the literature, but as far as I could tell, never recorded — I didn’t know of any commercially available recordings that included it, nor had I ever seen published spectrograms of it.  The Macaulay Library didn’t have it, and in the two different mornings I’d spent recording Bendire’s Thrasher in Arizona and California, I’d never even heard it, much less caught it on tape.  So I was pretty stoked.

I relayed the details of my sighting to my friend Andrew Spencer, who was due to arrive in southeast Arizona shortly after I returned to Colorado.  He was equally excited about this rare recording opportunity, and he made a point of stopping at the Sierra Vista Public Library as well.  That morning I got a message from him that relayed some good news and some bad news.  The good news: he’d found the bird right where I said it would be, acting just as I’d said it would, giving calls just like the ones I’d recorded.  The bad news?  It had been accompanied by, and fed by, two adult Curve-billed Thrashers.  It wasn’t a Bendire’s at all–it was just a juvenile Curve-billed.

Sure enough, when I went to look at the Bendire’s Thrasher chapter in Kenn Kaufmann’s Advanced Birding, there was the description of a juvenile Curve-billed Thrasher, matching my bird to a T.  I had forgotten that Bendire’s has a pale base to the lower mandible, which my bird had lacked.  And Kaufmann even mentions the single-syllabled call note of the juvenile Curve-billed.  Blast.

The morals of this story:

  1. Juvenile Curve-billed Thrashers look and sound far more like Bendire’s than I ever thought possible;
  2. Even the most seemingly slam-dunk IDs can be wrong;
  3. I still don’t know of a recording of the call of Bendire’s Thrasher.  Anyone?  Anyone?