Tuesday, May 27, 2014

How many trills can you remember?

There’s certainly been a lot of changes in the avian chorus lately, and early migrants head north, later ones arrive and then move on, and summer residents begin to establish their territories.  Some of the bird song identification challenges have actually gotten easier, too, such as my topic today: trills.

In musical language, a trill is a rapid alternation between two adjacent pitches.  In the 17th century, a trillo was a rapid repetition of the same pitch. 

 “Trill” is also used to describe the songs of birds that alternate quickly between two close pitches AND those that simply repeat the same pitch very rapidly.   Sometimes the verbal description just can’t convey enough information to be truly helpful.  For many people, even listening to recordings of different trills that particular species can sing could be challenging because those trills may be sung at different rates of speed. Even if the entire length of the song is the same, it will sound faster to us if more notes are sung in the same amount of time. 

For example, here are three Chipping Sparrows.  Their song is described in the Peterson Field Guide to Birds of Eastern and Central North America as “…a dry, chipping rattle on one pitch.”  That description is accurate, but what if you didn't know that they can sing faster or slower versions of their song?  You could easily assume that these are different species.

And then there's the Dark-eyed Junco.  “Song a loose trill, suggestive of Chipping Sparrow but more musical.”  More musical in what way?  I think it's a little sweeter, more jingling, and sounds like it has a less dry, abrupt cutoff at the end. (How's that for subjective?) And this one, too, can be sung at different speeds!

In my third Junco example, there are two Juncos singing close to each other at the Holden Arboretum in April.  One is singing a faster song than the other, and one could easily assume that two different bird species were singing.

The Swamp Sparrow's song is “…a loose trill, similar to Chipping Sparrow’s but slower, sweeter, and stronger.”  In this recording, you'll also hear other birds of marshes and wetlands in the background.  

And what about the Pine Warbler? “Song a trill on one pitch like Chipping Sparrow’s song, but more musical, slower.”  The tone quality is different – it’s much richer.  However, a Pine Warbler’s song can actually be faster than a slow Chipping Sparrow or Junco song. 

The Yellow-rumped Warbler also has a trilled song, and that one really is a little slower. It’s described as “Variable song, junco-like but two-part, rising or dropping in pitch, seet-seet-seet-seet-seet, trrrrrrr.”  However, sometimes it just sounds like a slower trill.  See what you think.

Here are Yellow-rumped and Pine Warblers singing very close to each other in April at Tinkers Creek State Nature Preserve in Portage County.  The Pine Warbler’s trill sounds  faster and more dense – there’s more sound and less space between the notes.  The Yellow-rumped Warblers are singing either a slower trill with a bit more space between the notes or the slightly more variable song described in the Peterson field guide.   

When I was standing near the edge of the ponds with pines trees just behind them, though, I had to really concentrate and think this through to be sure I really understood the difference between the songs.  They didn't generally sing one at a time so I could compare and contrast.  Not at all.  They overlapped, they sang simultaneously, and the Yellow-rumpeds sang two different forms of their song.  The quiz came before I could even study the material. 

When you’re first learning these songs, though, you don’t have to memorize all of the trills and compare them all to each other.  There’s an easier place to start.

Habitat and season.  Narrow down your choices.  You won’t hear all of these birds together at the same time in the same place.  Keep it simple.

Which of these trilling singers will be performing together on the same stage?  Unless it’s April, most will not.  I often consult Larry Rosche’s Birds of the Cleveland Region, published by the Cleveland Museum of Natural History.  I find this book to be invaluable for knowing when to expect specific species in our area and in which habitats they can be found.

Chipping Sparrows return in April, and they are common in open areas that have a scattering of trees.  They love golf courses, cemeteries, developments, campuses, and meadows with occasional trees, including evergreens.

Juncos are generally more northern birds that spend their winters down here in balmy Ohio.  They begin to sing in late March in advance of their departure, and many more Juncos from farther south sing as they pass through on their way north.  By the end of April, they’re gone EXCEPT for the NE corner of the state.  There, Juncos nest in hemlock ravines and other cool, wooded areas from the Chagrin River valley in eastern Cuyahoga County eastward through Lake, Geauga, Ashtabula, parts of Summit County, and surrounding areas.  Some have even begun to nest closer to people.  They will not typically be found with the Chipping Sparrows, though, as the latter are likely to be in more open areas and are commonly found closer to humans.

Pine Warblers return in April and, not surprisingly, they sing in pines – not a solitary pine or two in an open, developed area, but in a grove or forest of pines.  

The Yellow-rumped Warblers will be gone after April, so you won’t need to worry about sorting them out of the texture after the beginning of May. 

And Swamp Sparrows?  A few may stay here during the winter, but you probably won’t hear them singing before April.  And where will they be singing?  Marshes.  Where are the Juncos and Chipping Sparrows and Pine Warblers?  Exactly.  You’ve got it.  Just watch at the edges of their habitat, though. I once found a Chipping Sparrow singing its slow song near the edge of a marsh and would have assumed it was a Swamp Sparrow had I not investigated closely.

Only in April does it really get messy,  Juncos and Chipping Sparrows are quite likely to be singing together for a brief period of overlap, and if they’re in an area with pines there may be Pine Warblers as well. The Pine Warblers in the pines near the ponds, as at Tinkers Creek State Nature Preserve,  may be singing next to the Yellow-rumped Warblers in the deciduous trees bordering the pond while Swamp Sparrows sing in the nearby marsh. 

Once May gets established, it becomes much easier.  Remember that both Chipping Sparrows and Juncos can sing trills that are fast, slow, or in between, and consider the habitat where you're hearing the trilled song. Listen closely to the Chipping Sparrows, Pine Warblers, Swamp Sparrows and Juncos if you have then, and learn them in their contexts.  Then when everyone gets mixed together next April, you’ll be in a better position to sort them out. 

Oh, and about that first track: Yellow-rumped Warbler, Swamp Sparrow, Chipping Sparrow, Junco, Chipping Sparrow, Junco, Pine Warbler, and...another Chipping Sparrow. 


  1. You're helping with my nemesis songs! Interestingly, I don't know if the birds can always distinguish, either! We've been on the edge of a pine forest, playing a Pine Warbler recording and had Chipping Sparrows respond and investigate!

    1. What an interesting observation, Helen - thank you!

  2. Lisa, what a helpful and insightful post! I am a western birder so don't have to contend with some of your trillers. However, the junco/orange-crowned warbler comparison can be tricky at times. Usually, the OCWA sings a lazy trill that rises a bit then drops off and peters out, unlike the junco's evenly pitched trill. Then came the day I confidently IDed a junco by voice, looked up and it was a dang orange-crown singing a nice, evenly-pitched trill!
    Also, I teach a birding by ear course every year and find that many birders are terribly anxious to learn voices asap and then get overwhelmed and confused by trillers or other soundalikes. Your points on habitat and seasonality are so important for ear birders, to calm them down a bit and narrow their choices. I am constantly reassuring my students that time in the field is what makes a good ear birder, not choosing the right CD or app. But cruising the web to stumble upon blogs likes yours can sure make a difference!
    I've only gotten this far in your blog but look forward to reading and learning more.

  3. Thanks so much, Laura. Your bird song students are indeed fortunate to have you as an instructor!