Pacific Wren, Part Two

Pacific Wren, Part Two

It was a wet and foggy day in April.  I was standing in a damp little nook in dense woods, long before the first leaves would even think about opening, weeks before most migrating birds would get within a thousand miles of southeast South Dakota, listening to a cascade of musical notes that seemed like it would never end.  It was echoing off the trees and the mossy banks, coming from somewhere tantalizingly close — but from exactly where, I couldn’t for the life of me figure out.  After I stood there for perhaps ten minutes, I finally spotted it: a tiny brown bird singing from a pile of leafless brush, fifteen feet in front of me in plain sight.  My first Winter Wren.

By some strange coincidence, the details of that experience almost perfectly match the details of my first encounter with Pacific Wren, when, on another wet and foggy day in April, I spent another ten minutes trying to find the amazing vocalist hidden among the dense, damp vegetation, this time on the slopes of Skinner Butte in Eugene, Oregon.  At the time I had little idea I was seeing a different bird than the one I knew from the east.  The song was familiar, or so I thought — unmistakable, really.

To this day, in the field, I have some difficulty separating the songs of the two forms (which may be separate species soon, for those of you just tuning in).  Both are remarkable vocalists, with long-running musical strings of jumbled high-pitched notes and trills:

Winter Wren song, Hampshire County, Massachusetts, 20 June 2008. Recording by Andrew Spencer.
Winter Wren song, Hampshire County, Massachusetts, 20 June 2008. Recording by Andrew Spencer.
Pacific Wren song, Humboldt County, California, 28 March 2009.
Pacific Wren song, Humboldt County, California, 28 March 2009.

It’s not as easy as separating them by call, but with practice, Winter and Pacific Wrens are usually distinguishable by song.  Here are some points to consider:

  • First of all, in the above examples, don’t let the shorter Pacific song fool you.  Strophe length is variable in both forms, and Pacific’s songs may actually average longer than Winter’s.  Pay no attention to duration!
  • Although I can’t vouch for this across the board, the sample I’ve studied strongly suggests that Pacific Wren tends to sing with more trills given closer together, so that the song is composed of >50% trills, while Winter Wren tends to sing with longer jumbles of individual notes and fewer trills more widely spaced, so that the total song consists of <50% trills.
  • Tone quality is key. Many people consider the song of Pacific to be “drier,” or, in the words of Sibley, “more mechanical-sounding” and “buzzy” with “hard trills.”  The difference is one of musicality.  To my ear Pacific’s song sounds higher-pitched, but you’ll note on the spectrograms that the maximum and minimum frequencies of both songs are almost exactly the same.  The difference is that Winter Wren shows very little frequency change within individual notes (with the trills usually clustered at the bottom of the song), while almost every one of Pacific Wren’s individual notes sweeps from below 4 kHz to about 8.  Thus the difference is roughly equivalent to the difference we saw between the songs of Field Sparrow and Black-chinned Sparrow.  The Pacific Wren’s notes, especially its trills, are less musical because they are changing pitch too rapidly.  Practically every single one of the Winter Wren’s notes has a bell-like, musical quality, but the Pacific Wren has a much lower percentage of musical notes.

A good way to think of the difference in tone quality is to listen for the trills inside the wren songs and compare them in your head to the the “classic” song of Dark-eyed Junco and the “classic” song of Chipping Sparrow (which are, of course, themselves often difficult to separate by ear).  The Winter Wren tends to have the more musical, junco-like trills, while the Pacific Wren often trends towards an unmusical, Chipping Sparrow-like (or even Brewer’s Sparrow-like) lisping rattle.

Song delivery also differs, although this can be difficult to ascertain unless you have a great auditory memory.  Winter Wren males have only a few stereotyped songs in their repertoire; successive strophes of song are almost always identical.  Pacific Wren males sing with far more songtypes, and they also recombine their songs — the beginning notes of successive strophes are frequently identical, but the endings vary widely.

For more practice, and to hear some more of these fantastic bird songs, head over to Xeno Canto’s Winter/Pacific Wren collection.

11 thoughts on “Pacific Wren, Part Two

  1. Very timely posting for me, thanks (although I know this was a couple weeks ago). The topic of separating out Winter and Pacific has come up for me while researching a book project I’m working on, and you’ve summarized it nicely.

    This topic provokes me to rethink one of my best memories, however. About 4 years ago I was out walking along the Coast Trail at Point Reyes National Seashore, along a lush drainage leading out to the sea. I will never forget all the Winter, er, Pacific Wrens that were singing that day along the trail. It was just astounding, and simply awesome. However, my recollection is that the notes of their sings did in fact have more of that bell-like quality than what you are describing for Pacific Wren and have recorded and shared above. This may simply be my faulty memory, and it probably is, but it sure makes me want to take up recording and go back there and resolve this!

  2. but it sure makes me want to take up recording

    Go for it, Eric! Join the growing community of Colorado recordists.

  3. Nathan, Thank you so much for sharing your winter pacific wren blog with us. Being able to compare the two songs and calls and listen again and again is very helpful. I especially liked your comparison of junco and chipping sparrow songs.Urling Kingery

  4. My first Pacific Wren was a very similar story, camped in the State Park within Redwoods NP. Woke up with the loudest bird I’d ever heard, very new to birding, like about a year. Out of tent and spent ten minutes walking around one ten foot diameter shrubby bush before I finally found it. Could not believe so much noise, music, could be coming from something so tiny. Then got the field guide and figured it out. I now live in Arkansas where Winter Wrens are fairly common in winter (duh), but have been birding New England, and get to hear them sing their song there.

  5. Dear Nathan,

    I have listened to the songs this time and the difference in musicality between the two is even MORE striking! To me, even though you say the Eastern has less repertoire, his song is FAR richer musically and more enthralling! Rather like going from mono to stereo! IF I were only in the right place and could HEAR the bird through my Songfinder, I think I would surely be able to tell which one it was! However, here is another little problem: it seems to me–both from the photo and the sound–that the Winter Wren on my iPod is obviously the Eastern! So how would you get the Western on there–after the split?! I’m glad my converter box gave me such lousy PBS reception tonight–THIS was a lot more fun than TV! Mymm

  6. Guess what? Troglodytes troglodytes pacificus is not only on my desktop, but is now in my iTunes–all 40 seconds of it! So I can call it up and drag it onto my iPod anytime! It may not go where it’s sposed to with the other wrens, but it’ll be on there somewhere and I can always type it in to get to it! That’s what happened after I right-clicked on the hot link you gave me! MUCH THANKS! While I was poking around in my iTunes I found an old Winter Wren vocalization from the Peterson set that my nephew had put on my laptop a long time ago. It’s harder to deal with as it’s combined with several other N.A. wrens on one segment. I think it too, MAY be a Pacificus. But I’m not sure yet, so it’s a good one to practice on since I now have the archetypal Pacificus to compare it with! The beat goes on! Mymm

  7. I’ve been looking at the Winter Wren PHOTOS of both the eastern and western subspecies on my iPod and I think the Stokes people have put THE SAME PHOTO on there for both the eastern and western recordings. So you can’t learn much using THAT in the field! Have about decided to throw in the towel anyway, ‘cuz while I might be able to ID the song, neither one of ’em ever sings it here anyway. And the tiny calls are so subtle–IDing which would be which is A LOT HARDER when you don’t have BOTH to compare together. Even if I piggybacked off knowledgeable people who could make a definite ID, it wouldn’t do me much good since I couldn’t do a REPEAT performance later on myself. So it’d kind of feel like cheating. This is a good example of knowing WHERE and WHEN to draw the line according to one’s own ability. Much as I hate to admit it, making fine W.W. distinctions is probably beyond me–without having any opportunity to practice in the field. Too bad I handed my Songfinder over to some other woman while I was in Maine (with the ABA) that time. A Winter Wren was singing along the trail and I thought, “Oh, heck. you’ve heard winter wrens before on the west coast. And this woman’s deafer than you are and wants so badly to hear it!” So I handed her my Songfinder! MINUS ONE for me! Mymm P.S. I think the state records committee ought to require a sonogram of the call for ABSOLUTE PROOF before adding the Pacificus to the state bird list in the future! Too bad the A.O.U. can’t just leave us ALONE.

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