Earbirding

(Updated 7/10/2013 to include discussion of the audio files now available for download)

Princeton University Press recently sent me a review copy of Tom Stephenson’s and Scott Whittle’s The Warbler Guide, published this month.  This is one of the most remarkable books about bird identification that I’ve seen in recent years.

The quick summary:

• It’s huge. Only one inch shorter and 3 ounces lighter than the “big” Sibley Guide.  You won’t be slipping it into your jacket pocket.
• It has TONS of photographs — 38 photographs of Blackburnian Warbler in that species’ account, not counting the blown-up vignettes and comparison photos of similar species, or the photos in the wonderful flight comparison plates at the back of the book.
• It’s got spectrograms — illustrating an average of 4 song types per species, plus the “chip” and the “flight call.”  At last, a field guide that gives bird sounds the attention they deserve!
• It’s groundbreaking.  There’s more information here on warbler identification than you can learn in a year (if you don’t already know it) — and the authors have come up with multiple original ways to present it, many of them quite brilliant.

Disclaimer

I got the fine opportunity to review this book in part because it puts so much emphasis on identification by sound, including by spectrogram — which is what this blog is all about.  As you know, I’m currently at work on my own field guide to bird sounds. In some ways, The Warbler Guide treads some of the same ground, but it does so in its own way, and I have no connection to the authors or the publisher.

Visuals

The visuals in this book are tremendous.  The quantity and quality of the photographs outstrips anything I’ve seen in a field guide.

Maybe the best part is the comparison pages, most of which are called “finder guides”.  You want all the warbler heads on one plate?  All the undertails?  All the side views?  All the song spectrograms?  All the flight shots?  This book’s got comparison plates for all of these and more.  These pages alone are worth the cover price.

Layout

The book’s layout can be confusing, contributing to an overall sense of “information overload.”  For example, the Blackburnian Warbler species account proceeds as follows:

• Pages 1-2: photos of bright Blackburnians;
• Page 3: more photos of bright Blackburnians, plus photos of some comparison species (in this case, Yellow-throated and American Redstart);
• Page 4: how to age and sex Blackburnians, plus range maps;
• Pages 5-6: spectrograms: Blackburnian on the left, confusion species on the right;
• Pages 7-8: photos of drab Blackburnians;
• Page 9: more photos of drab Blackburnians, plus comparison species;
• Page 10: a full-page photo of a Blackburnian, just to keep the number of pages even.

The design makes it hard to tell when you’re “home” in a species account — that is, when you’re at the beginning.  And the ubiquity of comparison species, both in photos and spectrograms, blurs the borders between accounts even further.  If you, like me, are in the habit of scanning photos rather than words when looking for a particular species, then abandon all hope of navigating this book with ease.  (If you’re in the habit of scanning words, you’re still in some trouble, because all the photos are helpfully labeled.)  The only thing that saves this book from complete organizational disaster is the decision to order the species accounts alphabetically rather than taxonomically.  Normally I’m not in favor of this, but here, it’s a life-saver.

Spectrograms

The big news is that this book has spectrograms!  That fact alone makes me want to shout with joy from the rooftops.  At last we can see the sounds we’re describing.  This is the first major attempt to use spectrograms for identification since at least the 1980s, and it is long overdue.

It’s also a watershed moment for birding by ear.  A lot of people will use this book to decide whether spectrograms are worth using.  I fervently hope they will think so.  But based on the way the sounds are taught and presented, I fear that some readers, especially casual birders, may persist in the prevailing misconception that spectrograms are difficult, and “for experts only.”  If this happens, it will be the fault of the authors’ vocabulary.  A choice as simple as using the term “element” instead of “note” sends the message that song identification is a technical endeavour, not an intuitive one.

Their narrow focus on warblers both hurts them and helps them.  It allows them to simplify the discussion to three tone qualities — “clear, complex, and buzzy” — which is a simple and helpful distinction.  But the focus on warblers also tempts them to divide all songs into “phrases” and “sections.”  This terminology is great for explaining the difference between, say, Nashville and Tennessee Warbler songs, but it becomes very awkward when applied to, say, Canada Warbler, forcing the authors to write “many Phrases, almost all 1 Element” instead of the much simpler “almost never repeats a note.”  And their descriptions of “Expanded” and “Compressed” elements are so opaque that I fear they may do more harm than good.  I fear the same for the section on distinguishing between flight calls.

Again, though, they get the visuals right.  The spectrograms are high-quality, and underneath each one is a series of symbols intended to give a sense of how the song actually sounds.  When it comes to the pitch and rhythm of the sounds, these symbols are pretty intuitive, and they had me hearing the sounds in my head almost immediately.  I don’t know if they’ll work for everybody, but they might provide a “stepping stone” to help beginners translate between picture and sound.

Sounds

The book is accompanied by a downloadable playlist of audio files.  In a couple of years, we’re going to forget that serious books on bird ID were ever published without accompanying audio files.  And we’ll get used to paying more: it costs an additional $5.99 to download the audio collection.  You can purchase it separately from the book if you like.

The audio collection mirrors the book exactly.  The sound file named 180 a Blackpoll  Chip Call.mp3 accompanies spectrogram a on page 180, making it easy to go back and forth between audio and book.  If a particular sound appears more than once in the book (due to being included on multiple comparison pages), then it appears more than once in the audio collection as well. Unfortunately, the naming convention for comparison songs is confusing: 165 d Black-and-white  Blackburnian.mp3 is the Blackburnian song shown on the comparison page for Black-and-white Warbler.  There’s no Black-and-white Warbler in the audio clip.

The audio files are generally high in quality.  They are very short — a single song or a single call — and have been assiduously cleaned of background noise.  One really cool thing is that the audio files use spectrograms as the “album art,” so on most devices, the appropriate spectrogram pops right up when you play the song.  This little feature, more than any other aspect of the entire project, has the potential to get people visualizing sounds and change the way they listen.

One downside to the audio aesthetic is that it forces a narrow focus on single songs. There’s little mention of patterns of delivery — whether consecutive songs are similar or different — which can be useful for ID at times.  More distressingly, the single-serving recordings of chips and flight calls provide zero information about the range of variation in each species’ calls, and the careful scrubbing of background noise makes some of them sound unnatural.  Compared to Evans and O’Brien’s CD-ROM of flight calls, The Warbler Guide’s recordings are far easier to listen to and compare.  But Evans and O’Brien’s longer and more natural-sounding clips, even though they often roar with noise, provide lots more information to the ear.

Biology

This book is pretty much all identification, all the time.  There’s very little about biology and behavior — only what the authors deem useful in identification.  Many warblers employ a two-category song system, in which different categories of songs are deployed in different patterns for different purposes.   The research into these song systems is extensive, complex, and mostly absent from this book.  Many will applaud the narrow focus on identification, but I, for one, am sorry that the book teaches me little more about these fascinating birds than simply how to tell them apart.

The bottom line

All in all, this book is a must-have for serious birders.  Beginning and intermediate birders should also check it out, and not be too discouraged by the sheer volume of information.  I am confident that this book will enhance the way people look at warblers.  I am less confident, but ardently hopeful, that it will enhance the way they listen to warblers as well.

In 1985, the Cornell Laboratory of Ornithology partnered with the Borror Lab of Bioacoustics and Ontario Nature to produce Songs of the Warblers of North America on LP by Donald J. Borror and William W. H. Gunn.  No other source of that time period could claim to be as comprehensive: it contained no fewer than 280 cuts of song from 57 species of warblers, including mega-rarities from Mexico like Fan-tailed and Golden-crowned Warblers — even the extinct Bachman’s Warbler!  In addition, it included recordings of calls for all but eleven of those species.  For decades, this collection was the last word in warbler sounds.

Now, 25 years later, Cornell has re-released this classic, this time in MP3 format for digital download.  The song recordings are just as high-quality as ever, and I’m thrilled by the idea that their digitization might make them accessible to a whole new generation of bird enthusiasts.  But great though it was in 1985, the collection desperately needs to be expanded and revised — so desperately that I’m not sure I can recommend forking over the fifteen bucks for the download.

Here’s what I like about the collection:

• The songs sound great. The cuts are nicely edited and, at about 25 seconds apiece, just long enough to stay interesting.
• They capture the range of variation well in most species.  After listening to the five Borror and Gunn cuts of Olive Warbler song, you’ll be totally confused what an Olive Warbler sounds like — but anyone who listens to Olive Warblers for more than an hour in the field will be equally confused, so I call that a job well done.
• The coverage of rare species is good.  In particular, those recordings of Bachman’s Warbler are true gems.

Here, unfortunately, is what Cornell should do if it really wants to update this guide:

• Fill in the gaping holes.  Eleven species lack any recordings of calls whatsoever.  If they were all Mexican vagrants, I might understand, but Wilson’s Warbler?  Black-throated Blue?  You’ve got to be kidding me.
• Bring the booklet up to snuff.  The accompanying brochure currently includes only the barest minimum of information.  It says nothing of the behavioral context of the vocalizations.  The “Type A” and “Type B” songs of many species are here, but they aren’t labeled as such, nor are subspecies labeled — so I can’t tell whether both “Western” and “Yellow” Palm Warblers are represented, for example.
• Add flight calls. Andrew Farnsworth and colleages at Cornell have amassed a downright impressive collection of warbler flight calls, including many that don’t appear on Evans and O’Brien’s classic DVD.  Why not stick them on here?
• Add flight songs.  Even the well-known flight songs of Ovenbird and Common Yellowthroat are missing.
• Improve geographic coverage and representations of possible splits.  It’s nice that Myrtle and Audubon’s Warblers are treated separately, but where’s “Calaveras” Nashville Warbler?  How about Mangrove Warbler, or at least “Golden” Yellow Warbler?
• Include common hybrids.  At a minimum, give us a Blue-winged × Golden-winged gallery with a dash of Hermit × Townsend’s.
• Add Crescent-chested Warbler. The rarity coverage isn’t bad, but by now this species has certainly occurred north of Mexico often enough to merit inclusion.

Nostalgia is great and all, and Borror and Gunn accomplished something truly monumental in their day, but bird sound collections are supposed to be tools, not collector’s items.  And as a field tool, this reissue doesn’t quite meet the modern standard.

Let’s face it: the era of the commercial bird sound collection is pretty much over.  You can pay $15 for Borror & Gunn and listen to four examples of the song of Black-throated Gray Warbler and one example of its calls — or you can head over to Xeno-Canto and download (as of this writing) five examples of song and three examples of calls, completely free of charge.  For better or worse, the internet has democratized bird sound publishing, and anybody who still wants to make money off of sound identification guides has got to add some serious value.

When it published Voices of North American Owls in 2005, Cornell added that value.  The booklet accompanying the two CDs ran to 56 pages and described the behavioral context of each vocalization in detail.  The collection as a whole aimed to catalogue the entire repertoire of each species, and did a pretty darn good job of it.  By and large, the recordings of the common vocalizations were of a higher quality than anything you could download off the internet for free, and the recordings of the rare vocalizations simply weren’t available anywhere else.  Add to that the convenience of having all those sounds in one pre-assembled package, and you’ve got an audio publication well worth the $30 price tag.

With the reissue of Borror and Gunn, the convenience of pre-assembly accounts for almost all the added value.  The quality of the song recordings and the historical significance of the work make up the rest of it.  Whether that totals $15 is a judgment I’ll leave to you.

Here’s my personal judgment.  If I were the Cornell Laboratory of Ornithology, after performing the genuinely valuable service of digitizing this historic collection, I’d generate some goodwill by donating the whole thing to Xeno-Canto, as Bernabe Lopez-Lanus recently did with his colossal DVD Bird Sounds from Southern South America (6100 recordings from over 1000 species).  Barring that, I’d  invest the time and money it would take to really revise and update the project.  Anything less fails to do justice to the original work of Borror and Gunn.