J-Pod and K-Pod Vocalizations from 12/10

Even though I'm down in Portland, I'm still getting "whale updates" and have had the chance a couple of times to listen to the whales on the Orca Sound hydrophone network. The evening of December 10th was especially cool, with J- and K-Pod vocalizing off and on for several hours in Haro Strait. (Note: the whales spend much less time in the inland waters during the winter months, compared to the summer but they've not-unexpectedly been in and out of Puget Sound all fall.) Thanks to Jeanne's recent posts I found a way to embed audio right into my blog post, so I hope you enjoy this 3:12 clip of the orcas vocalizing. Near the beginning you will hear the three-part descending calls that are characteristic of J-Pod. Closer to the end you will hear the high-pitched kitten-like calls of K-Pod.

Orca acoustics has been my area of research and right when I began studying the whales it intrigued me that you could identify which pod or pods are present simply the the vocalizations that they're making. In the case of the Southern Residents, the three pods (J, K, and L) share a set of +/- 25 different call types. Each call is named with an "S" for Southern Resident, then a number, so the calls are S1, S2, etc. Many calls are shared between all three pods but each pod has a certain sub-set of the shared repertoire that they use more often. For instance, S1 , one of the calls heard near the beginning, is almost exclusively a J-Pod call. Even among shared call types, such as S16, pods can have different "accents" to them, allowing you to tell them apart. S16 is one of the K-Pod calls heard towards the end of this recording, and I know it's K-Pod because it's so much higher pitched than when J- or L-Pod makes the same call.

K26 Lobo emerging from the dark depths of the ocean where he has been "talking" about....?

Even though we see the whales on an almost daily basis during the summer it's important to remember that they only spend 5% or less of their time at the surface. The vast majority of their life is spent in comparative underwater darkness, which is for them an acoustic realm rather than a visual one. While we rely primarily on visuals to identify individual whales, and study whales using the visual behaviors we see (breaches, tail slaps, etc.), I think their true secrets are locked up in their acoustic communication.

Orcas are one of the most heavily-studied marine mammal acoustic systems, and when people hear we've been studying orca acoustics for 40+ years, they often wonder if we have "cracked the code" and figured out what they're saying. In reality, we're nowhere close. It's not like in some animal communication systems where a single call can be paired with a single behavior. Instead, calls are used across all behavioral contexts. As I learned in my undergraduate thesis, there's a greater structure in how the calls are used, with certain call types often being linked together in their usage. The truth is we don't have a clue what they're talking about. I think that's pretty darn cool.