A Pygmy-Owl Challenge

A Pygmy-Owl Challenge

The Northern Pygmy-Owl is a fascinating bird for those of us interested in vocalizations and taxonomy.  Many people think that what we call “Northern Pygmy-Owl” may contain somewhere between two and four species, based on regional differences in vocalizations.  Here’s a brief overview of the differences, according to The Sibley Guide to Birds (2000), with a typical spectrogram and sound of each:

Pacific birds

According to Sibley, birds along the Pacific Coast of North America “give very slow single toots (1 note every 2 or more sec).”  The example below is even slower than most; 2.5 seconds between notes seems pretty standard.  Although one might expect birds in Montana to be part of the Interior West group, the sole recording available seems to fit better in this group.

Interior West group

Very few recordings of this group are available online (or anywhere else) — just two or three from Colorado [1 2] and one from Utah.   They all seem to give single notes at very regular intervals, just over 1 second apart, totalling about 50 “toots” per minute when they’re going full-bore.

Mexican group (“Mountain” Pygmy-Owl)

Sibley says these birds “give mainly paired notes more rapidly (about 1 pair every sec).”  Paired and single notes are usually mixed together, as on the recording below, and the paired notes are only slightly closer together than the single ones:

"Mountain" Pygmy-Owl (Glaucidium gnoma gnoma), Big Bend National Park, TX, 3/28/2008.

However, “Mountain” Pygmy-Owls also sometimes forgo the paired notes in favor of a rapid-fire string of single hoots almost identical to the song of the Northern Saw-whet Owl:

What we don’t know

What exactly is this Northern Pygmy-Owl saying? You could help us find out. Photo taken 11/4/2008 in Mission, BC by NechakoRiver (Creative Commons 2.0)

Nobody knows exactly where the changes between these songtypes occur, or how abrupt they are, because we just don’t have enough data.  Most recordings of Northern Pygmy-Owl are of the highly vocal Mexican birds.  As I mentioned above, very few recordings exist of the Interior West birds.  There are none from potential areas of transition, like Idaho, Wyoming, northern Arizona, or New Mexico.

Now, my friend Arch McCallum is setting out to get to the bottom of this tricky situation — and you can help.

If you have access to Northern Pygmy-owls anywhere in their range this spring and summer, please do one of the following:

  1. Find a singing pygmy-owl.
  2. Get out a stopwatch and count how many “toots” the bird makes in one minute.
  3. Send this information, along with location, date, and time of day, in an email to Arch (mccalluma   AT   appliedbioacoustics.com) or post it in the comments below.

If you wish, you can also make a one-minute audio recording.  (Just take a video with your digital camera, or get a cheap voice recorder if you don’t already have the means.)  Actually, if you wish, you’re welcome to record (or listen to) the bird for longer than a minute!  The more data, the better.

Hope to see a lot of data points roll in this spring!  Here’s to good owling.

7 thoughts on “A Pygmy-Owl Challenge

  1. Thanks to Nathan for his summary of the problem, and to Arch, in advance, for taking the challenge of bettering our understanding of regional differences in vocalizations. After hearing of Arch’s goal last night, I looked through my notes on NOPO observations, and was chagrined to discover that only once had I timed an owl’s tooting. I’ll do better this year — and hope to encounter NOPOs in areas I haven’t birded before!

    To encourage others to help Arch, I’ll share what I sent him about the one occasion I timed an owl’s tooting: “12 July 2010, along Lower Forbestown Road, Plumas NF, Butte County CA, elevation about 2650 ft, beginning at 7:45 and continuing until 8:48 pm I had an owl nearby, attracted by my tooting.. Here’s what I wrote shortly afterward: ‘During the time the bird was tooting without my stimulation (although after such stimulation), I timed its tooting. Twice I timed for 20 toots (starting my stop watch immediately after a toot). Each time it got these 20 toots off in a shade less than 40 seconds, so one toot every two seconds for this example of G. g. californicum.'”

  2. Thanks for a great summary of current knowledge of Pygmy-Owl variation, and I’m glad to hear that someone is going to take on this project – it’s badly needed. I was interested in your description of the Mexican birds as “highly vocal”. That’s certainly my experience. I heard lots and lots of Pygmy Owls during my time in southeastern Arizona, but have heard them on only a few occasions in California (where I’ve spent more time than in Arizona) and I’ve personally never heard one in the Rockies (where I’ve spent less time, but still quite a bit). Maybe this has to do with population density, but if it’s generally true it’s going to make ANY data people can get from the Rockies that much more important.

  3. My experience matches yours, David — despite living in the southern Rockies, I rarely hear Northern Pygmy-Owls. They do sing regularly in the right habitat at the right time of year and day, but those Mexican birds seem to sing anytime, anywhere. Most of my recordings of “Mountain” Pygmy-Owls come from mid-morning (between 9 and 11 AM). I don’t believe I have ever heard a pygmy-owl singing at that time of year in Colorado, although I certainly know people who have.

    I do think Northern Pygmy-Owls are far less common in Colorado, in general, than they are in SE Arizona, California, or Oregon, so that may explain the difference.

  4. I live in Victoria BC, Canada. I come across Pygmy Owls on a regular occasion here just west of Victoria in and near the Sooke Hills. Yesterday, on April 10, 2011, I timed a Pygmy several times for a minute at a time, and it averaged 18 calls per minutes, about 4 seconds apart. This is the usual timing for the Pygmy’s I hear around here. A few years ago I heard a Pygmy calling in paired notes with about 2 seconds apart from the pairs, but the usual is what I experienced yesterday, 4 second intervals
    The Pygmy’s are fairly vocal in this area.

  5. Your comment about Montana Pyg Owls was interesting, but you didn’t note what part of the state. Recall that the wet Pacific-slope forest creeps into NW Montana, bringing a fair number of species typical of that habitat with it, e.g., Chestnut-backed Chickadee, Varied Thrush, and Townsend’s Warbler. I would actually be surprised if the pyg-owl in that neck of the woods WEREN’T of the Pacific coast form, whatever the taxonomic level.

  6. Tony,
    The Montana bird was 20.0 km NE of Clinton, in Missoula County. Clinton is SE of Missoula, so the locality is more Rocky Mtn. than Interior Wet Belt. Pinicola supposedly gets into NE Oregon , so there is quite a bit of wrap around of the ranges. Your bigger point is well taken. Considering the habitat, would one expect grinnellii, rather than californicum to be the form in the Selkirks and other interior wetbelt ranges. So many good questions!

  7. Last week (14-15 May 2011) I was birding with my friends and fellow advanced birder Carl Lundlbad (currently Tucson, AZ), and his family members Danny and Sally Paez (Albuqeurque, NM). We spent the night of 14 May 2011 camping in Clanton Canyon – the “Bootheel” of NM in Hidalgo Co. – a favorite site for NM birders, where we typically get whiskered screech, western screech, northern pygmy and sometimes saw-whet owls. The following morning (15 May 2011) we hiked along the dirt road from camp (Geronimo Trail) on our way to another canyon. As we approached a site known as “Geronimo Seep” or “Turkey Seep” we began to hear a Pygmy owl singing to our south about 300 meters or so. The time was about 0850h and the bird sang until at least 0905h. The bird was not seen, but appeared to be in a tall Chihuahuan pine (one of 3 trees that penetrated and stood above the lower canopy of juniper, pinyon pine and mixed oaks). The pygmy owl song rate concept was fresh in our minds thanks to Rich Hoyer’s recent posts on the AZ NN Bird listserve, so I decided to time the song. I did this twice, here’s the results:

    1. about 65 toots per minute; toots included double-toots and single-toot phrases
    2. about 85 toots per minute; toots included double-toots and single-toot phrases

    I sent this info to Arch in an email, with location data.
    We hope to be back in the area in June and maybe later in the season as well…I’ll try recording with my camera or Olympus voice recorder next time.

    Also, in my past extensive experience in the isolated Big Burro Mtns (Grant Co, NM) 2006-2011, all the pygmy-owls I encountered (mostly 1st week of May each year) were apparently of the Mountain type, based on rate of calling, which was always more than 1+ toot/min. Unfortunately my only video of a singing owl was deleted from my files (d’oh!).

    Las Cruces, NM

Comments are closed.

Comments are closed.