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Author: Nathan Pieplow

Speaking of Quizzes

Speaking of Quizzes

Jason Beason just informed me of a brand new biweekly audio quiz set up by Rocky Mountain Bird Observatory at http://rmboaudio.blogspot.com.  I think this is a marvelous idea.  In fact I once harbored aspirations of running an online audio quiz of my own, but now that I actually have the means to run one (via this blog), I find myself reluctant to do it.  You can expect an occasional quiz like the one I just ran on crossbills, but I’m not planning on it as a regular feature.

The RMBO quiz will be the only regular, moderated bird sound quiz on the web, as far as I can tell.   There are certainly automated quizzes on the web — the Patuxent Bird Sound Quiz is fun — but I don’t know of any other blog-style audio quizzes whose challenges change on a regular basis.  Let me know if I’m missing any!

I find it odd that audio quizzes are so rare, but then I find it odd that photo quizzes are so rare also. I disagree with Kenn Kaufmann’s assertion that online photo quizzes are “legion.”  It’s quiz photos that are legion, not photo quizzes.  Anybody can post a photo of a mystery bird to the web, but it’s rare to find an outlet with the discipline to do it regularly, publish the answers with educational explanations, and keep track of the winners’ scores.

By the standard I’ve just laid out, for my money, the best moderated photo quiz in the world is Mr. Bill’s Mystery Quiz, now known as the Colorado Field Ornithologists Photo Quiz, which was started by Bill Maynard in 2003.  The ABA Online Bird Photo Quiz is also venerable, dating from the same year, but it only changes monthly, which means they’ve only published 78 quizzes so far.  Mr Bill is run weekly, so it’s on quiz 318, believe it or not!  If these are the two best and most regular photo quizzes on the web, can it be coincidence that Tony Leukering is moderating both of them at the moment?  The man is remarkable.

In addition to their audio quiz, RMBO is starting a photo quiz as well.  The CFO/Mr. Bill and ABA quizzes are geared towards intermediate to expert birders, while both RMBO quizzes are going to serve easier fare.  And I think that’s appropriate, especially on the sound side, since I find that sound quizzes tend to be harder than photo quizzes — particularly in the absence of information about the time and place of the recording.  I look forward to seeing (and hearing) what they post!

The Crossbill Quiz: Answers

The Crossbill Quiz: Answers

Here are the answers to the quiz from the last post:

a. Type 4

Type 4 is believed to specialize on the cones of Douglas-fir.   It is widespread but somewhat irregular in its distribution: it is usually common in moist forests of the Pacific Northwest and can be frequently found in dry forests there also.  It is regular in southeast Arizona, and indeed this particular recording was made at Barfoot Junction in the Chiricahuas in May 2009.  It appear to be absent some years from Colorado, but fairly common in other years; 2009 saw a decent influx of this type into the state.

Ken Irwin (unpubl.) has proposed that hidden inside Type 4 there is another call type,  Type 10, that specializes on sitka spruce in coastal California.  It’s still unclear to me whether Type 10 is a separate call type or just a variation on Type 4.  Whatever the case, Type 10 seems to wander widely, at least across the northern states, out to New England and Maryland.

The Type 4/10 group, as a whole, sounds very distinctive because of its upslurred calls.  It may be a little hard to hear that they are upslurred because they are delivered so fast, but the rising, flicking quality of the calls is pretty distinctive, reminding some people of the “whit” calls of Empidonax flycatchers.

b. Type 9, the South Hills Crossbill

This type is sedentary and restricted to the South Hills and Albion Mountains of Idaho, where it feeds on the local variety of lodgepole pine.  It sounds kind of like Type 2, clear, simple, and downslurred, but it is noticeably low-pitched.  I think it is kind of “dull-sounding,” without much ring or resonance, but I’d be interested to hear how other people describe the difference.  I recorded this in the South Hills in September 2009.

c. Type 2

Here’s a Type 2.  This is probably the most numerous crossbill in North America; it is common almost everywhere Red Crossbills can be found.  It is surmised to specialize on ponderosa pines.  Across its range its calls are variable, but the high-pitched, clear, downslurred quality is fairly distinctive.  This recording was made in Boulder County, Colorado, in July 2007.

d. Type 3

This is one of the smallest crossbills (only Irwin’s proposed Type 10 is similarly small) and is one of the most common crossbill types in moist northwestern forests, apparently specializing on western hemlock.  It also can be found across the boreal forest, occasionally into New England, and it wanders rarely into the southern Rockies — there are now two certain records for Colorado and more in the “probable” category.  There are also recordings from Arizona.

Types 3 and 5 sound similar to my ear: they are more complex than the types we heard above, less clear and less obviously upslurred or downslurred.  Type 3 is the duller-sounding of the two, but I must admit I need practice with this identification.  This particular recording, the second-ever for Colorado (from the Grand Mesa, February 2009), was made by Andrew Spencer when I was right beside him–and I didn’t turn on my microphone because I thought they were “just” Type 5s.  To be fair, Andrew recorded them because he thought they were White-winged Crossbills.  🙂  He didn’t identify them until days later when he looked at the spectrogram.

e. Type 5

This is the “other” common crossbill in Colorado (besides Type 2), a widespread bird of high elevations in the West, apparently adapted to feed on lodgepole pine but also very fond of Engelmann spruce.  In direct comparison I think it sounds more “metallic” than Type 3, but it’s a tough call in the field.  A distant flock can sound a lot like a bunch of crickets.  This recording was made in Larimer County, Colorado, in June 2009.

The Crossbill Quiz

The Crossbill Quiz

Last week I facilitated the Sound Identification Panel at the Western Field Ornithologists Conference, which is a wonderful privilege I have been treated to for each of the last four years.  For those who don’t know, the Sound ID Panel is an annual WFO tradition started by Sylvia Gallagher. In front of a large live audience, a moderator (that’s me) quizzes an expert panel on the identification of mystery bird sounds.  This year our panelists were Ted Floyd, Oscar Johnson, Jon Feenstra, Rich Hoyer, and Tayler Brooks, and I must say they did an outstanding job.  In collaboration with each other, and notwithstanding the occasional wrong answer, they managed to identify almost every mystery sound in the end, and believe me, that’s not an easy feat.

In 2009 I decided to cross a line I’ve been reluctant to cross in the past.  I put Red Crossbills in the mix.  It seemed natural, since the conference was in Idaho, home to the endemic South Hills Crossbill, and our keynote speaker was crossbill guru Craig Benkman.  I gave the panel the following quiz:

Red Crossbill Call Types: Matching

In this quiz you’ll hear one example of each of the four most common and widespread crossbill types in the western United States, listed below with the tree species they are believed to specialize on:

  • Type 2 (Ponderosa Pine)
  • Type 3 (Western Hemlock)
  • Type 4 (Douglas-Fir)
  • Type 5 (Lodgepole Pine, Rocky Mountain variety)

Plus, given the location of the conference, we’re tossing in the sedentary and range-restricted South Hills Crossbill, endemic to Idaho, which has been proposed as a separate species, Loxia sinesciuris:

  • Type 9 (Lodgepole Pine, South Hills variety)

Here are the sound clips in random order.

a.

b.

c.

d.

e.

How well can you do?  Answers will be posted in a subsequent message.

Back from Prewitt, Off to Boise

Back from Prewitt, Off to Boise

The Labor Day weekend was a busy, sleepless one for me: I helped Ted Floyd lead a three-day workshop on nocturnal migration for the ABA’s Institute for Field Ornithology.  We got up early all three days (ridiculously early on Monday, so that we could head two hours east to Prewitt Reservoir on the Colorado plains) and listened for the microscopic (microsonic?) flight calls of warblers and sparrows overhead in the dark.  Then, after it got light, we did some birding to correlate what we had heard with what we could see on the ground, and we fired up my computer for some spectrographic analysis of the morning’s “take.”  A good time was had by all.

I’d love to recap in more detail and post some of the weekend’s sounds, but that will have to wait until I get back from the Western Field Ornithologists Conference in Boise, tomorrow through Sunday.  Appropriately enough for a conference in Idaho, the keynote speaker is crossbill expert Craig Benkman, and at least one field trip will head to the South Hills for the endemic crossbill there.  I hope to return with better recordings of the elusive “Loxia sinesciuris” than I was able to get in April.  And, for the fourth year in a row, I’ll be chairing the Sound ID panel, which is always among the highlights of my year.

Look for more postings from me next week!

The Coolest Bird Sound

The Coolest Bird Sound

In the opinion of the late Rich Levad, the Black Swift was The Coolest Bird, and in his still-unpublished manuscript of that name, he advanced a pretty strong argument for its coolness.  This is a bird that spends much of its time foraging so high in the air that nobody ever sees it.  It nests in the spray zone of waterfalls, so that a juvenile may never have dry feathers between hatching and fledging.  And it is poorly understood: to this day we really have nothing but educated guesses as to where the species spends the winter.

It appears that will change soon. My friend Jason Beason of Rocky Mountain Bird Observatory sent me this announcement:

As of the evening of August 24th there are three Black Swifts in Colorado wearing light-level geolocators! On that evening, Kim Potter, Carolyn Gunn, Todd Patrick, Chuck Reichert, and myself caught ten adult Black Swifts using mist-nets in the Flat Top Mountains in western Colorado. The locators were placed on two females and one male, all of which weighed greater than 50 grams (the minimum cutoff to stay less than 2% of total body weight). In just a few weeks the swifts will begin their migration to locations unknown. With string and ribbon included the total weight we added to the birds was only 1.8 grams! With luck, this time next year we will be able to report where these birds spent the winter of 2009-2010. If not for the help of Carolyn Gunn, a trained veterinarian with very nimble hands, we could not have placed these devices on the swifts in a reasonable amount of time. We are very thankful that she agreed to help with this project!

Black Swift in hand with geolocator. Photo by Carolyn Gunn.
Black Swift in hand with geolocator. Photo by Carolyn Gunn.

The light-level geolocators that Jason referred to are the same technology used by Stutchbury et al. 2009 to estimate the migratory paths of Wood Thrushes and Purple Martins, birds too small to carry the satellite transmitters like those the Pacific Shorebird Migration Program has placed on Bristle-thighed Curlews and Bar-tailed Godwits in recent years.  Jason later reported to me in a follow-up email that a fourth Black Swift was outfitted with a geolocator at Box Canyon, near Ouray, on 29 August.  Unlike the satellite transmitters, the geolocators do not send data in realtime; it will be lost unless the birds are recaptured next year and the data downloaded.  Since Black Swifts are extremely faithful to their nesting sites, the team thinks there is a good chance they will be able to retrieve one or more of their geolocators a year from now.

One of the reasons Black Swifts are so little known is that they are rarely observed, even near their nest sites.  I believe that one of the reasons they are rarely observed is that most people don’t know what they sound like.  Unfortunately, one of the reasons why most people don’t know what they sound like is that they’re devilishly difficult to record.  Over the past couple of years I’ve found that Black Swifts are actually quite vocal, particularly near the nest — but the nests are usually so near waterfalls that recording is basically impossible.

Thanks to Rich Levad and his army of Black Swift volunteers, the number of known nesting sites in Colorado has more than tripled in the last decade, and at some of these sites, it’s possible to get a reasonable recording.  With better recordings comes a greater chance of detecting Black Swifts when they are overhead.  I have sometimes been able to find this species by ear when I wasn’t expecting it or looking for it, and I’m not the only one.  So let’s spend some time on identification by ear.

The individual “pip” notes of the Black Swift are extremely similar to the “pips” of Pygmy Nuthatches, and they can sound similar to some notes of Red Crossbill.  Rarely, the swifts will make a longer, higher-pitched “squeak” noise.

Black Swift vocalizations, Larimer County, CO, 23 August 2007.
Black Swift pip & squeak calls, Larimer County, CO, 23 August 2007.

Sometimes Black Swifts give a relatively stereotyped “extended call” that starts with a rapid twittering series of “pips” and culminates in a clear “squeak.”  This is often followed by a decelerating series of “pips.”

Black Swift extended call, Larimer County, CO, 23 August 2007.
Black Swift extended call, Larimer County, CO, 23 August 2007.

Black Swift vocalizations in general, and the extended call in particular, appear to be correlated with aerial chases, although all vocalizations are also given by some solo flying swifts and by perched individuals at or near the nest.  Nor are these vocalizations limited to the daytime: at least at their nesting sites, Black Swifts will vocalize throughout the night.

You can hear more examples of Black Swift recordings in Xeno-Canto’s collection.

Mountain Quail after all?

Mountain Quail after all?

Don Roberson of Creagrus fame sent me an interesting and provocative email in response to the old pygmy-owl vs. chipmunk thread (1 2).  With his permission, I’m reproducing it here for discussion:

A possible word of caution regarding analysis of chipmunk calls as discussed at http://earbirding.com/blog/archives/454:

I don’t necessarily disagree with your conclusions, but there are caveats to be considered. You may have already considered them, but on the off chance you have not, here they are.

1. You rely heavily on Brand (1976) for your starting point, and he studied primarily “Townsend’s Chipmunk” as stated. However, this was prior to the acceptance of the split of “Townsend’s” into four species, as proposed by Sutton & Nadler (1974) and Sutton (1987) [citations below]. Now, the 4-way split is universally accepted.

One of the major reasons for the split was the differences in vocalization between the four species. One of the two papers, probably the 1987 one, goes heavily into differences in calls. It has been a while since I’ve read them, and I don’t recall whether he went into “chips” versus “chuks” but a full background in the vocal differences between the for “Townsend’s” types is important before drawing generalizations from Brand’s 1976 paper. I don’t know how many species of chipmunk Brand reviewed, but there are 25 species in North America.

For more on chipmunk i.d., with some discussion of calls, see my 3-page web set on chipmunk i.d. that starts at
http://creagrus.home.montereybay.com/chipmunks.html
The Townsend’s four-way split and i.d./calls is on page 2 of the set;

2. The call you have posted as probable Merriam’s Chipmunk “chuk” is a very commonly heard vocalization at Chews Ridge. I live in Monterey County and probably know the spot better than any other birder. I have never seen a chipmunk giving the call, although Merriam’s is common there. In fact I have puzzled over what does give the call. I have cautioned many times about claims of pygmy-owl there because of this note. However, I have generally attributed the note to Mt. Quail. In doing Breeding Bird Atlasing there and other similar habitats in the Santa Lucia Mts., there have been circumstances when a Mt. Quail was seen not long after and close to the source of the call.

If it is Merriam’s Chipmunk, that is very interesting, because it can be given in a steady and prolonged series that I haven’t attributed to chipmunks. [On the other hand, ground-squirrels do give a series of steady, prolonged, evenly-paced calls, so it is reasonable that a chipmunk would as well.]

Did any of your correspondents actually see a chipmunk doing these series of steady calls in California? I do think this could be the right answer to the mystery, but I would appreciate some analysis on why it is not a Mt. Quail.

Thanks, Don

Sutton, D. A. 1987. Analysis of Pacific coast Townsend’s Chipmunks (Rodentia: Sciuridae). Southwestern Naturalist 32: 371-376.

Sutton, D. A., and C. F. Nadler. 1974. Systematic revision of three Townsend’s Chipmunks (Eutamias townsendii). Southwestern Naturalist 19: 199-211.

In response to a couple of Don’s questions, I’ll say:

  1. Chipmunks definitely do give long steady series of call notes, both “chips” and “chucks”; the probable Least Chipmunk I recorded in Michigan vocalized at a nearly constant rate for over 12 minutes.  I did visually identify that one as a chipmunk, although didn’t make a visual ID to species.
  2. Some of my correspondents have seen chipmunks making pygmy-owl-like sounds in California, although it’s apparently more common for the source of the sound to be unseen.
  3. I have tracked down the two sources Don cited; if you want PDF copies, email me.  The 1987 paper mentions vocal distinctions only briefly, citing a personal communication from William Gannon and publishing no spectrograms.  Another paper may go into the differences; I haven’t found it yet, but I haven’t searched long either.  Gannon gave a paper at one point — Influence of proximity to rivers on chipmunk vocalization patterns. Gannon, William L. Special Publication the Museum of Southwestern Biology. 1997 24 March; 3:273-285 — but I haven’t had a chance to track it down yet.

I think we may have a lot to learn about chipmunk vocalizations!  Comments?

New Listserv Alert

New Listserv Alert

Last spring Chris Tessaglia-Hymes of Cornell University started a listserv devoted to the discussion of nocturnal migration.  Here’s how Chris described it in his inital post:

The primary purpose of the List is to provide an effective electronic forum for experienced birders to discuss the identification of night flight calls of migratory birds, exchange ideas about recording equipment design and setup, disseminate information about active or predicted night flights in your area, and to better understand weather and RADAR data as they relate to patterns of nocturnal bird migration.

The listserv started off slow, but it has slowly gained participants (including, just recently, yours truly), and now that the southbound nocturnal migration is in full swing across North America, the postings are really picking up.  You can monitor the discussion at the online archive.  To join the list, you can email Chris to request that he add you, or you can check out the Welcome and Configuration page.  Either way, this is a great opportunity to join (or just to listen in on) the national conversation about nocturnal flight calls!

Recordist Profile: Paul Hurtado

Recordist Profile: Paul Hurtado

In response to my last post, Paul Hurtado suggested that I periodically profile recordists and their equipment, as a service to beginners and those shopping for new gear.  I loved the idea, and since it was his (and he volunteered), I’m starting with a profile of Paul himself.

Paul Hurtado in the Adirondacks.
Paul Hurtado in the Adirondacks.

According to the bio he sent me, Paul grew up roaming the wild lands around Pueblo, Colorado in search of all things spineless, scaly, slimy or feathered. Since graduating from the University of Southern Colorado, he has been working on his Ph.D. in Applied Mathematics at Cornell University, using mathematical models to study the ecology of infectious diseases.

Here’s the run-down on Paul’s recording gear:

  • Microphone: Sennheiser ME67 shotgun microphone with K6 (AA battery) power supply (purchased on eBay for around $250-$300)
  • Shockmount & windscreen: homemade.  The shockmount for the microphone is fashioned out of PVC pipe, flat aluminum stock, screws and wingnuts from the hardware store, plus shock cord from an outdoor store.  The windscreen consists of men’s dress socks. (Editor’s note: homemade shockmounts are really cool and I’d like to talk more about them in a future post.)
  • Recorder:  Sony Hi-MD minidisc recorder, model MZ-RH910, with the external AA battery pack
  • Cable: 3-pin XLR-to-stereo mini cable to connect the mic to the recorder
  • Headphones: regular walkman-style

And here is said gear posing for a photo, with the dress-sock windscreen pulled partly off so you can see the microphone and the skeleton of the shockmount:

4-recorder_mic_mount_visible

Paul says:

I originally wanted to get a recording setup to record rarities or interesting breeders (e.g. out of range Chihuahuan Ravens, empids, etc.), but I more often find myself doing other things instead. So far, I use it mostly for personal enjoyment of some of the more common local species and the occasional vocal migrants. It’s a great way to get out and spend time just observing a few individuals for a relatively long period of time. Nest vocalizations, territorial disputes, all these things are amplified enough to reveal a lot of cool behavior you just can’t experience under most circumstances.

I do occasionally chase “target species” I’d like to record (e.g. winter finches are always a treat here in western New York), as well as night-flight calls during migration (although a nice Bill-Evans-style parabolic mic would work way better than a shotgun mic). I’ve used my recording setup to “turn up the volume” for a friend of mine who is somewhat hearing impaired over some frequency ranges, and I even brought it along on a two week field course I helped teach a couple of winters ago down in the Carribean. While recording conditions were horrible during the course, I did get a few “ok” recordings of species that were the subject of student field projects, which they were then able to use in their presentations at the end of the course.

Listen to the sounds of a Vervain Hummingbird (Mellisuga minima) that Paul recorded in Punta Caña, Dominican Republic, in January 2008.  The recording is faithful to both the bird and its slightly noisy surroundings:

And here’s another nice recording of Paul’s, of a Hammond’s Flycatcher (Empidonax hammondii) in Pueblo Mountain Park, Pueblo County, Colorado, on 31 May 2006:

You can contact Paul through his website if you have any questions for him about recording!

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 Oldbird.org, 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 Oldbird.org is Bill Evans’s website, not Michael O’Brien’s.

Another Chipmunk Mystery

Another Chipmunk Mystery

This past week I was in Michigan, where I had an opportunity to get out and do some recording on a couple of mornings.  My earlier posts (1 2) on chipmunk “chuck” calls had stimulated my curiosity in mammal sounds, so when the chipmunks started calling all around me, I turned on the mic — and lo and behold, I got something pretty interesting:

Chipmunk "chuck" call, Peshekee Grade Road, Marquette Co., Michigan, 8/6/2009 (20-43).
Chipmunk "chuck" call, Peshekee Grade Road, Marquette Co., Michigan, 8/6/2009 (20-43).

I was struck by the similarity of this sound to the mystery call from California that was probably made by a Merriam’s Chipmunk.  I can confirm that the Michigan sound came from a chipmunk: after a few minutes of hunting I spotted the little guy on the ground only 10 feet away, twitching his head forward slightly with each call.  Unfortunately, I was under the mistaken impression at the time that only one chipmunk species inhabits the Upper Peninsula of Michigan.  Upon returning home, I discovered that the U.P. actually has two species, Least and Eastern:

Least Chipmunk photoEastern Chipmunk photo
Least Chipmunk (Tamias minimus), Glacier National Park, Montana. Photo by Phil Armitage. Eastern Chipmunk (Tamias striatus), Bas-Saint-Laurent, Quebec. Photo by Gilles Gonthier (Creative Commons 2.0).

If I had been paying attention, I could have identified the little guy to species by looking at his size, shape, and facial striping — but I wasn’t paying attention, so now, alas, I have to use the recording to figure out which ‘munk was chipping.

And there’s the rub.  The vocalizations of Least and Eastern Chipmunks have been described in the literature (e.g., Bergstrom & Hoffman 1991, Burke da Silva et al. 1994), but I can’t find a published spectrogram of this particular sound.  Nonetheless, the evidence points to this being the “chuck” call of Least Chipmunk.  Reasons:

  1. The “chuck” call of Eastern Chipmunk has been well studied, and I’ve heard a couple of recordings of it (e.g., this one), which sound nothing like what I recorded;
  2. The Michigan sound is similar to the probable Merriam’s Chipmunk “chuck” from California, and all western chipmunk species (including Least) are supposed to have similar “chucks,” according to Brand (1976).  Eastern Chipmunk is not closely related to other North American chipmunks.

The Least Chipmunk is the most widespread chipmunk species in North America, occurring throughout much of the Rocky Mountain and Great Basin regions, plus the boreal forest from the Yukon to the U.P. and southwest Quebec. In much of its range it is common, and in many places it is the only chipmunk.  So, those of you who know something about chipmunk vocalizations, this one’s for you: has anyone heard a sound like this from a Least Chipmunk?  How about from an Eastern?  How good is my tentative ID?