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.
I'm thinking of a chattering teenager trying on different personalities...
ReplyDeleteI 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!
ReplyDeleteNice. 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.
ReplyDeleteLooking forward to more posts!
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!
ReplyDeleteI 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.
ReplyDelete