Paul A Schwartz
3 Nov 1965
- Rancho Grande; km 10.5
- 10.3666667 -67.6833333
- 600 meters
- NAGRA III
- Electro-Voice 650
- Parabola 91.4cm (36in)
NOTES: Neotropical Institute Cut # 12. Bulk reel: 40
a) 10:05 PM. Natural song; a lower-voiced bird. Bird #1. Quality: 2. Level: +10.
b) 12:00 PM. Bird #2. After considerable playback. This bird has a higher voice than #1, which may be heard in background. This high-voice bird could not be brought close for collecting to check on the sex. I did not collect the other bird for I'm reasonably sure it is a male and wanted to leave it with the hope that at some later date I can find it with a mate and then make a better comparison of songs and then check sex.
Note that in the background is also heard one of the "conflict or bother" calls, songs or screams.
c) 4/XI/65. ~ 10:15 PM. This is no doubt #1 again, the next night. It had not been singing but was quickly brought in by playback. This recording was made slightly "off-focus" to minimize the parabola effect. Recordings made @ 7.5", then 15", then 7.5" again. Recording made some time after playback and the song is quite "normal."
Finally there is one song recorded directly "on focus." Note the harsher quality of the sound, especially in the final notes. But note also that there is an even greater sounding difference from the first four songs of part c) when I was further away from the bird (and could not see it, so focus only by ear and no doubt there was much vegetation between the owl and me).
Note: These three different sounds should be subjected to analysis by spectograph to see the differences. Also compare the 15" recording.