Happy 4th! Bigg’s killer whales heard at Bush Point

Thanks to Orca Network — both for hosting the Bush Point hydrophone and for alerting the network (via a post to the shared Orcasound App Facebook page) that Bigg’s killer whales were heard on the morning of July 4, 2020. Starting at around 8:30 a.m. (Pacific time), calls, clicks, and buzzes were recorded. You can listen to the ~10 minute period when the density of signals was the highest:

10-minute highlight in Ogg format
10-minute highlight in MP3 format

Here’s what that clip looks like as a spectrogram with preliminary labels:

The total duration of the acoustic bout was roughly an hour, with extended periods of background or boat noise in between periods of orca sounds. The first period had the most intense sounds; the second was pretty faint. Here’s the full hour-long recording in .ogg format:

1-hour recording in .ogg format (34MB)

The tide was low in Admiralty Inlet at the time (about -1′) and falling, so the water/surface noise increased during the bout (because the hydrophones are strapped to the outer pilings of the Bush Point B&B wharf, so nearly uncover during extreme low tides). At some points in the recording you can hear bird calls reaching the hydrophone through the shallow water.

The first human detection of an orca sound was at 8:46:08 via the new “I hear something interesting” button in the Orcasound live-listening community science web app. Here’s what the fledgling list of detection candidate looks like towards the end of the listening session:

It’s exciting to have both Bigg’s and Southern Resident Killer Whales around during the past week. We’re still warming up for a new summer season of marveling about soniferous Salish Sea species, but with a couple Facebook posts and a notification email, the Bush Point hydrophone peaked at 23 listeners today. Many arrived as noise from a sailboat masked the orca sounds, but those who kept listening witnessed the 2nd bout of Bigg’s calls, clicks, whistles, and buzzes.

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