ML252460861

Age

Not specified

Sex

Not specified

Observation details

The first audio file began at 4:52 am. It is heavily edited to remove conversation and some of the worst background noises as we walked around to find the best location to record the birds. The flycatchers nsinging about 30 m west of the nest site on the opposite side of Battle Creek near the ford. Arch McCallum's Applied Bioacoustics website illustrates the spectrograms of 3 song phrases given by each of Cordilleran Flycatcher (COFL) and Pacific-Slope Flycatcher (PSFL). We recorded many examples that matched the COFL Song Phrases 1 and 2 proving that a maleCordilleran Flycatcher was present at this location. Song Phase 1 is a single note at a specific frequency producing a short horizontal line in the spectrogram. Its frequency is slightly lower than 6 kHz in Cordilleran Flycatchers and slightly higher than 6 kHz in Pacific-Slope Flycatchers. I measured 13 examples of this phrase from my recordings and found that they were all at 5.4 or 5.5 kHz suggesting that the singer was a Cordilleran Flycatcher. I noted that Song Phrase 1 was often given about 1 second before Song Phase 2 in my dawn recordings. A clear example of song phrase 1 occurs near 58.0 seconds in my first audio file. Song Phrase 2 has a more complex pattern. McCallum’s website illustrations indicate that this phrase has a sharp peak that extends above 7 kHz in Pacific-Slope Flycatcher and has an arched maximum with a peak frequency below 6 kHz In Cordilleran Flycatcher. The shapes of their spectrogram is very different for these 2 species. I have measured 18 examples of song phrase 2 in my recordings and they all exhibited an arched maximum shape with a peak frequency of 5.9 kHz again implying that the singer is a male Cordilleran Flycatcher. Its shape most closely matches the fifth example of Song Phase 2 for Cordilleran Flycatcher on the McCallum website. A clear example of Song Phrase 2 occurs near 49.7 seconds in my first audio file. My final recording of a song phrase 2 was at 5:11 am. The second audio file was recorded across the creek from the nest site beginning at 5:24 am. It contains many examples of the COFL Male Position Note (MPN). Most of the MPN are broken into 2 parts. A clear example is at 56.5 seconds of this file. Note that this broken MPN starts well below 4 kHz and ends near 6 kHz. This matches McCallum’s description of the frequency range for COFL whereas he indicates that PSFL frequencies start above 4 kHz and end well above 6 kHz. He states that only COFL have broken or discontinuous MPN notes but some COFL have continuous MPN notes. This broken MPN note was the most frequent MPN note that I recorded on site. Take a close look at the spectrogram of the second audio near the 2 minute 48 second mark. There are a series of broken COFL MPN but a single example of an unbroken continuous MPN at 2 minutes 48.5 seconds. The unbroken note overlaps 2 fainter notes from another bird. It is much stronger in the B channel than in the A channel. This note appears only once whereas the other notes shown are all broken notes of near equal intensity in both channels suggesting that the bird is perched to the side of the recorder. These broken MPN notes repeat at semi-regular intervals of about 4 seconds. Because this extra continuous MPN note breaks the pattern and is stronger in the B channel, I believe I watched this bird giving the unbroken note fly directly from the nest towards the recorder as it called. I conclude that it was emitted by a DIFFERENT individual. There must be at least 2 male Cordilleran Flycatchers present in the area of the nest on July 11. The unbroken MPN is also given at the start of this audio file. It has been suggested that the third Cordilleran Flycatcher may be what ornithologists call a "floater". At one point, a second (male?) COFL visited the nest while another individual (female?) was present. It passed its food to the first bird who then fed the young. This bird then removed a fecal sac.

Technical information

Dimensions

1261 pixels x 945 pixels

Original file size

408.85 KB