Tuesday, October 11, 2011

Deciphering Communication to Understand Behavior

One of the most interesting forms of animal communication comes from deep in our world's oceans. Once a mostly unknown topic, researchers are beginning to understand and recognize patterns of whale songs. Scientists have been using devices called hydrophones to distinguish sounds made by different whale species. Hydrophones were used in the past only for detecting underwater earthquakes, but sounds from ships, marine landslides, and whales have led to an increased interest in whale songs.

One of the most important things to note is that not only do different species of whales have separate sounds, but some species have different "dialects" depending on where they are from. For example, blue whales off the Pacific Northwest have slightly different songs than blue whales of the Western Pacific Ocean. Scientists have yet to determine if this difference is from learned behaviors or genetics. Once labeling a specific sound to a population of a certain whale, scientists can determine where the migration patterns and living preferences of these whales are. This is very important to the study of whales, as the previous method of counting and tagging a creature that can go as deep as 3000 meters underwater for 2 hours can be difficult. These Navy hydrophones can pick up whale sounds from up to 40 km away, or even farther, depending on ocean depth and terrain. One example in this article was how these devices picked up the sounds of an immense number of sperm whales who happened to be living in the Gulf of Alaska in the winter. Previously, all whaling records and other sightings have shown sperm whales in this region, but only in the summer months. It was thought that the Gulf of Alaska was too cold to harbor almost half of Alaska's sperm whale summer population.

Overall, the same techniques that we have studied in class on Raven are currently in use to analyze whale songs. This information is in turn used to determine where different whales like to spend their time and/or migrate to in the winter. I thought this was very interesting how it correlated to our in class discussions, basically deciphering whale communication to determine whale behavior.

10 comments:

  1. Jacob- that's actually really interesting, how whales seem to have distinct dialects based on where they're from, like some of the bird species we've been talking about lately. You mentioned the blue whale, and that it still hasn't been determined if it's behavioral or genetic; I wonder how they plan to figure this out? I mean, cross-fostering with whales of other regions to compare the vocalizations produced is unrealistic with something as large as a whale.. But I wonder if they have conducted any studies on young rescued whales, and comparing how they react to whale songs from their area versus a population found in another area..?

    I'm also wondering if these distinct 'dialects' are only seen in whale species that have highly isolated populations..? Because I know that the different blue whale populations tend to be highly isolated, so maybe that plays a role? Same with more specialist species of whales, like the beluga whale, which are found only in arctic/subarctic waters. It'd be interesting to look into, maybe comparing the amount of variation in vocalizations of specialist/highly isolated species to a more common whale species, with a wide geographic range, where multiple populations are more likely to interact.

    Posted by Brianna Eddy

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  2. This post reminds me of what we talked about today about how certain birds of dialects. My question is , is this gender specific. Do female whales have these changes in dialects like the birds we talked about in class today? Also why did the dialects change if these whales tend to be isolated and where did they learn how to communicate this way? Theses are some of the questions that I would ask if I were to conduct this study.
    Posted by Jobin Oommen

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  3. This article makes me wonder how loud the ocean actually is for a whale. Do whales hear different species songs and how do they react to them? Do they ignore the calls and steer clear of each other or do other species interact. This article makes me wonder if whales of different species share migration patterns or if these calls allow them to plot migration patterns that they don't cross paths on.

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  4. My first thought reading this post was that the hydrophones are not only more reliable and effective at tracking whale communication, but they also sound a lot safer for the whale, as well. Tagging the whales probably made propellor scars an issue in some cases and stressed the whale out a lot more than simply listening to them.

    What prompts the call of a whale? Do males mostly call, like in the birds we have been talking about in class? Is it for territory and breeding, specifically? I would think that they call to keep track of each other. This hydrophone method can probably help us figure out not only the whales' locations throughout the year, but also the context of their calls based on their age and the time of year.

    Posted by Chelsea Van Thof

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  6. This topic also made me reflect on our class discussion on bird songs. I wonder how their calls developed, whether or not they are learned of innate. If they do learn these calls such as some species of birds do, do they have a preference of tutors? Can migrating whales learn the calls of other species in order to adapt to their new environments? Also does their learning process have different stages similar to the ones we see in bird songs? These are some of questions researchers could use to gain further insight into these whale calls and dialects.

    Posted by Sara Corey

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  7. I think its really cool that we now have the technology to categorize whale sounds/songs. I wonder if whale songs are similar to bird songs, in that they have the same basic form but need to be practiced during a sensitive period in order to be perfected. Also I wonder how much whale songs differ than say bird songs because the medium used for sound is now water instead of air. Does this allow sound to travel further? Also does it give the ability to create songs with higher frequencies?

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  8. I wonder if whale songs will shift with changing climates. Global warming is changing the temperature, currents, and salinity of the ocean, and as the sound medium changes, maybe the songs will too. This could be looked at in a rudimentary way by studying different calls at different depths, which have different pressure levels.

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