We often study cetaceans (🐳🐬) by deploying underwater microphones (called hydrophones) & observing them acoustically instead of visually! But how do scientists identify whale species by sound alone? Another #MarMamFacts thread! 🧵⤵️ 🌿🧪🔊 (1/6) - ThreadSky

daryllmarie.bsky.social • 421 days ago

We often study cetaceans (🐳🐬) by deploying underwater microphones (called hydrophones) & observing them acoustically instead of visually! But how do scientists identify whale species by sound alone? Another #MarMamFacts thread! 🧵⤵️
🌿🧪🔊 (1/6)

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simonhco.bsky.social•3 days ago

As a linguist I love to see spectrograms 😍

daryllmarie.bsky.social•3 days ago

We need more spectrograms on this app!

marygemignani.bsky.social•4 days ago

Thanks for such a great thread!!

daryllmarie.bsky.social•4 days ago

My pleasure! I’m scheming to write many more this summer!

jenschuld.bsky.social•141 days ago

I heard some SRKWs on our local hydrophone just a little while ago!

daryllmarie.bsky.social•141 days ago

Ahhhh so cool! We never get orca on our hydrophones unfortunately 😭

daryllmarie.bsky.social•421 days ago

Different whale species make unique sounds, similar to how a bald eagle and a blue jay, both bird species, have distinct vocalizations. Properties of vocals that may differ between whale species include frequency, duration, & call rate. So you record some whale sounds, what’s next? (2/6)

daryllmarie.bsky.social•421 days ago

Next up is often not listening to the sound, but graphing it! Not all whale sounds are audible to humans, easily discernible, & easily distinguishable from background noise. Graphing solves those problems & makes patterns clearer. Spectrograms are graphs of signals, in this case sound signals! (3/6)

daryllmarie.bsky.social•421 days ago

Spectrograms show time on the x-axis, frequency on the y-axis, and loudness by color brightness. This way, you can see patterns in sound frequencies over time and study the properties of loud or notable sounds. Next up, let’s look at an example spectrogram from Širović et al. 2011 ⤵️ (4/6)

daryllmarie.bsky.social•421 days ago

Ex. Those dark red spots are 4 individual loud sounds. They all have frequencies of ~15-35 Hz, are ~1 sec long, & are ~12 sec apart. Fin whales make what we’ve named “infrasonic pulse calls”. They’re usually short pulses of ~20 Hz in repeat chains like this, 8-16 sec apart. It’s a fin whale! (5/6)

fritsoul.bsky.social•141 days ago

super cool. About to read more

daryllmarie.bsky.social•421 days ago

It’s not always that easy… most whales make multiple call types, many species overlap in call repertoires, & call patterns can differ btwn populations & years. This is also a pretty example chosen for a paper. Most spectrograms are messier. But there is so much we can learn via these tools! (6/6)

theecheese.bsky.social•421 days ago

How cool is all this!

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