Monday, February 18, 2013

An unusual late-winter song



An unexpectedly early song for me this late winter/early spring has been that of the Song Sparrow.  Although some do overwinter here in NE Ohio, I typically don’t hear their songs in my area until March.  I was quite surprised to hear a Song Sparrow singing at the Holden Arboretum on February 6th as cross-country skiers glided past his frozen pond!  If you listen closely, you may be able to hear the sound of the skis.



It took some effort to find him, but I finally saw him in the dense shrubs along the edge of the pond.

However, I noticed that his song sounded a little odd.  What was different about it?

Song Sparrows have a repertoire consisting of quite a few songs. They can - and do - change between them in response to other singing males.  However, when they are singing, they repeat one song pattern until they choose to switch to another.  Songs often seems to have three parts, with most including a buzzy trill.  After each song statement, there is a pause before the next statement of the song.  This recording of a bird singing at Holden in late March a few years ago is a typical example.  There is a bit of variation in the closing of each song phrase, but it’s generally quite consistent.


But that was not the case with this Song Sparrow.  If you listen to the longer recording of his song, you may be able to hear that his phrases are not distinct and his motivic material is not consistent.



Interestingly, around the same time I heard a Song Sparrow at Pond Brook Conservation Area in eastern Summit County that sounded so variable it actually resembled a Catbird!

So what’s going on with these highly-variable songs? 

I began to search for more information and came across an interesting article on this topic by Donald J. Borror in the May, 1968 issue of the Ohio Journal of Science.  To my delight, it contained a specific example of variability in early spring Song Sparrow songs!  He wrote,   

Song in the Song Sparrow (Melospiza melodia) (Mulligan, 1966), for
example, begins with a soft, barely audible warble, generally in late summer of
the bird's first year. Later, usually during the fall or winter, some notes and
phrases of the adult song appear; by February or March, these notes and phrases begin to be organized into a sequence, and songs (or fragments of songs) begin to be repeated. Before the final form of the song is developed, the songs may be similar to those of the adult, but more variable. By March or April (rarely a little later), when the bird is nearly a year old, the final form of the adult song becomes crystallized.

The songs of many birds (including some migrants) in early spring are in a
pre-adult stage of development; they are often quite variable, and frequently
lack the characteristic form of the adult song; they are often sung at a faster
cadence. The song patterns are eventually perfected and, once perfected, are
generally fixed for life. Developmental stages of song can usually be recognized
by variations in the songs, imperfections of the song patterns, and the season in
which they are heard.

When I returned to his pond today, he was still there.  There was snow on the ground again, and skiers were still cross-country skiing past his frozen pond.   It was windy and no one was doing much singing, but what I heard from him already seemed to have a bit more form.  I’ll continue to check on his progress – perhaps I’ll be able to tell how much work he is able to do on his own before an abundance of Song Sparrows encircles the entire pond in late March.

5 comments:

  1. I'm thinking of a chattering teenager trying on different personalities...

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  2. I never realised song sparrow songs were that variable. As seasons change, I forget old songs and have to re-learn them in the spring. I tend to be confused for quite a while. Perhaps, I can blame the birds themselves for my sluggish memory!

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  3. Nice. I think the theory is that the youngster is matching what comes out of his beak with templates he internalized while listening to his neighbors the previous late summer and fall. Interestingly, the templates in most species that have been studied don't come from Dad.

    Looking forward to more posts!

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  4. This is destined to be an outstanding blog, Lisa, and I'll look forward to many more excellent posts such as this one on Melospiza melodia! Which, by the way, were singing it up big time around here today!

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  5. I heard a similar "tuning up" from a young Bewick's wren one year. He just had to warbler a bit to get it to all come together.

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