Listening to a Continent Sing

the companion website to the book by Donald Kroodsma


Yorktown National Battlefield, Yorktown, Virginia

May 16; 5:52 a.m.

Sunrise at 5:56 a.m.

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Two Carolina wrens duel along the York River, just below the redoubts that commemorate the last fighting of the Revolutionary War. How fascinating to listen in on their conversation. The male in the foreground sits on a dead snag, singing nonstop for about 12 minutes (only four minutes of which are presented here). If one focuses just on him for these four minutes, one hears a marvelous sequence of five different songs (A B C D E), delivered in an intriguing sequence (see table below).

4-Minute Sequence of Songs by Foreground Carolina wren

1 (B)* A A A A A B B A B B B A B

2 B A (D)* B B C D C C C C C C C

3 C C C C C C C C C C C C C C

4 C C E C E C E C C E D D D

  • In parentheses at the beginning of minute 1, I indicate that the background bird is singing song B, which he does until minute 2 when he introduces song D, which he continues singing for the remainder of this four-minute selection.

See and hear how the foreground bird comes to match the background bird with song B in the first minute, and then matches song D as well, just once in minute 2, three times toward the end of minute 4 (and throughout minute 5, not shown).

Note the asymmetry in the song exchanges. It is the foreground bird who sings so excitedly, often alternating songs and matching the song that his neighbor offers. The background bird seems to sing more calmly, offering many consecutive renditions of B and then D. The neighbor sings with less passion, it seems, and it is the foreground bird who is trying to keep up, trying to match his neighbor. I wish I knew the relationship between these two birds and all that had transpired between them to produce this kind of exchange.


A few very distant birds, such as northern cardinal, chimney swift, purple martin, American crow, but the real story is the second Carolina wren singing in the background.


Photo by John Van de Graaff