Orcasound’s Greatest Hits of 2021

2021 was a fantastic bioacoustic year in the critical habitat of the endangered Southern Resident Killer Whales (SRKWs, salmon-eating type). Not only did we have the privilege of hearing the calls, clicks, and whistles of those salmon-seeking orcas, we also heard more than usual from both Bigg’s (mammal-eating) killer whales throughout the year and humpback whales during the fall and winter.

All in all, the combined efforts of human listeners around the globe and the OrcaHello AI system built by Microsoft volunteers identified some 75 bioacoustic events — a new record! Of these, 49 were SRKWs calling, 11 were Bigg’s events, and 14 were humpbacks vocalizing.

Here is a “playlist” of short clips that contain the best sounds from 2021:

The “best” sounds are a combination of what we think was of greatest bioacoustic interest, highest acoustic quality (e.g. signal-to-noise ratio), and just fun and beautiful to hear from Nature.


Last August, for about a half hour in the evening (~19:25-20:05) the OrcaHello AI and attentive Orcasound listeners heard diverse calls interspersed with many clicks as they monitored the Orcasound Lab hydrophones in Haro Strait (5km south of Roche Harbor on the west side of San Juan). This is a short (~3 minute) sample of what these orcas sounded like:

(ogg format; download via 3-vertical-dots at right)
(mp3 format; download via 3-vertical-dots at right)

And here’s a visualization of that highlight clip:

The Center for Whale Research reported that the pod might include the L54 matriline which seems mostly consistent with the call types that were recognized during the live listening event and near real-time review of the automated detections. As the sun set, the residents continued north past Henry Island.

Bigg’s killer whales

Also in August, we were treated to what Dr. David Bain called “one of the longest series of transient killer whale calls I’ve ever heard…” This bioacoustic event occurred a couple hours after sunset on the Bush Point hydrophone in Admiralty Inlet. Here’s what they sounded like (with some high-pass and other filtering to reduced the system noise levels a bit):

.ogg format
.mp3 format

Here is what Bigg’s killer whale calls looks like as a waveform and a spectrogram (in Audacity):

You can explore thousands more 1-minute clips that our AI thought might be of interest via the OrcaHello moderation portal.


In the fall of 2022, we heard humpback whales in Haro Strait more than ever before. Of particular interest to our resident expert this winter, Emily Vierling, was a repeated sequence of three sounds: a “Growl,” a “Whup,” and an “Ascending Moan.” Listen to this clip from October 28, 2021:

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Here is what a single sequence of these three sounds looks like as a waveform and a spectrogram (in Audacity):

If you’d like to hear and learn about more humpback sounds, try this Orcasound blog post about humpbacks howling last Halloween. And stay tuned: in 2022, Emily plans to publish an Orcasound catalog of humpback sounds that we commonly here within the inland waters of Washington.

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