61. Sage thrasher songs, through the night.
7. When to Sing, and How
Night singing
From page 127 in the book.
Sage thrasher songs, through the night. How (and when, where, why) birds sing in the night puts us in largely uncharted territory. For three nights, from the evening of June 12 to the morning of June 15, 2018, in Sierra Valley, California, I placed a Swift recorder (see "Recording birdsong") near a male's night roost. He obliged with an outpouring of song, and for two mornings I followed him after he left his night roost, to enable a comparison of his "day" songs with his "night" songs (♫518-531).
You can use these recordings to explore so many questions that are currently unanswered: Exactly when in the night does he sing? Is it the same pattern night after night? How do night songs compare to day songs, in duration, complexity, or whatever other measure you can come up with? In just a quick sampling of songs from ♫523, just aftermidnight on June 14, I was astonished to see that this free-wheeling bird that I knew from the daytime, who sang what seemed an endless variety of songs, was repeating himself, with successive songs at times identical! Compare songs at 8:14 and 8:58, for example, or the two at 14:14 and 15:24, or the five-second songs at 24:06 and 24:44. I did not realize that a sage thrasher was capable of repeating himself like this.
I love listening for mimicry: soras, barn swallows, so many more. After marveling at the enormous variety of sounds, I pick one that I can readily distinguish from all the others, such as the two pure-toned notes that sound like the introductory notes of a vesper sparrow song; in ♫528, hear them at 1:36, 2:37, and 3:48. Then I try to find them again. Want to join me in the search? The search is faster if you scroll through the sonagrams in Raven Lite, without actually listening. Any luck finding where those particular notes recur? What have you learned about sage thrashers in the process?
Morning of June 12
♫518. Here is a good sample of dawn singing after the male leaves his night singing roost. In the distance, hear one song from this male's night perch (from 0:02 to 0:17); by 0:25 he is flying toward where the microphone will record him for the next 99 minutes! 4:50 to 6:29 a.m.; sunrise at 5:33 a.m. June 12, 2018. Sierra Valley, California. (1:38:37)
Night of June 12-13
♫519. Sporadic songs recorded during evening of June 12, early morning of June 13, from 9:10 p.m. to 2:38 a.m.; sunset at 8:30 p.m. Recording consists of 10 brief sections, with fades between. Songs occur at the following times after sunset: 9:10 p.m., 11:32 p.m., 11:38 p.m., 11:41 p.m., 12:41 a.m., 12:55 a.m., 1:05 a.m., 1:31 a.m., 2:12 a.m. (2 songs), 2:38 a.m. (total duration of singing, 1:38).
♫520. Continuous singing begins at 2:43 a.m., continuing to 3 a.m. in this recording. (16:27)
♫521. Continuous singing, 3 a.m. to 4 a.m.. (1:00:00)
♫522. Continuous singing, 4 a.m. to 4:52 a.m. until he leaves his night roost. During the last four minutes, he seems to have moved closer to themicrophone—-a real ham! (51:47)
Night of June 13-14
Sunset (8:30 p.m.) to midnight: No singing.
♫523. 12:00 a.m. to 1:00 a.m. Singing from 12:16 a.m. to 1:00 a.m. (total duration of singing, with long silent intervals removed: 43:35)
♫524. 1:00 a.m. to 2:00 a.m. Continuous singing. Coyote chorus begins at 43:40. (1:00:00)
♫525. 2:00 a.m. to 3:00 a.m. Continuous singing from 2:00 a.m. to 2:14 a.m., followed by three brief songs given at 2:21, 2:24, and 2:41 a.m. (recording has fades between those songs). (14:01)
♫526. 3:00 a.m. to 4:00 a.m. Three brief songs given at 3:01 a.m., 3:20 a.m., 3:43 a.m.; then a group of five songs beginning at 3:48 a.m., then continuous singing from 3:54 a.m. to 4 a.m. (8:10)
♫527. 4:00 a.m. to 5:00 a.m. Continuous singing until 4:52 a.m., when he leaves his night roost and flies to a nearby fence line (recording continues in ♫528). During the last three minutes, he's louder, as if he's perched higher and perhaps closer to the microphone, where I have erected a fence post just in case he wanted a higher perch. (51:38)
♫528. 4:52 a.m. to 6:15 a.m.; sunrise at 5:33 a.m. At 0:15 in this recording, just after he departs his night roost, the male flies past the microphone and lands on the fence post about 10 yards away. From there, he sings almost nonstop for 44 minutes, then more distantly for some time before returning to sing near the microphone again from roughly minute 57 to 63, and again from minutes 73 to 83. (1:23:16)
Night of June 14-15
Sunset (8:30 p.m.) to 12:00 a.m.: No singing.
♫529. 12:00 a.m. to 1:00 a.m. He sings isolated songs at 12:20, 12:41, 12:48 (recording has fades between songs), and then he begins singing at 12:55. (5:39)
♫530. 1:00 a.m. to 2:00 a.m. Continuous singing. (1:00:00)
♫531. 2:00 a.m. to 3:00 a.m. Continuous singing until 2:19 a.m., and then nothing until 4:50 a.m., when he can be heard in the distance at his dawn singing perch. Where was he between 2:19 a.m. and 4:50 a.m.? Still in his night perch and quiet? A great distance away (about one hundred yards or more) so that the microphone would not pick him up? My best guess is that he was in place and quiet—-but that seems so unlike what he did the previous two nights. (19:14)
Perhaps a confession is in order. The night singing was recorded by a Swift recorder (monaural; see "Recording birdsong" for the recording gear I use) placed near the bird's night roost. I was not there. On two mornings I arrived about 4 a.m. to be ready for his singing once he departed his night roost; those songs, when he was on the fence posts beside the road, were recorded with a stereo shotgun microphone (Audio-Technica BP4027). I wasn't there then either! I was off listening to western meadowlarks, marsh wrens, yellow-headed blackbirds, and whatever else was singing. The sage thrasher predictably sang from the same perches, so he took care of recording himself.