Humpback whales sing for their food. Who knew?
People worldwide have been captivated by the sound of humpback whales singing, and whether members of this species sing as a means of communication with each other or some other purpose. Our Greenland expedition cruise participants often ask this very question. Interestingly, scientists have recently discovered that an important purpose of the humpback whale's song is to help them locate their next meal.
How do whales utilize singing?
Marine biologists have long believed that humpback whales sing as a form of interaction with each other. This can vary from helping them during mating season to informing other whales about changes in weather conditions. Interestingly, a research team from Syracuse University used some footage captured by a drone to determine that humpback whales work together to corral prey near the surface.
How does the singing impact their prey?
It is likely that whales occasionally sing in the dark when they are having a difficult time finding enough nourishment. The Syracuse researchers referenced above have recorded a “tick-tock” sound that hunting whale partners make to remain connected while searching for food at night.
During the night, eel-like sand lances are the humpback whales' prey of choice, and research indicates that these small fish spend a lot of time buried inside the ocean floor. This is a good survival tactic, but there is one significant problem for them: sand lances will often come out of hiding in response to the noises that whales make.
There’s a downside...
Singing for one's supper in this manner sure seems practical, but it also exposes the hunting location of each whale to any other whales from outside its pod. Evidence even suggests that the whales from outside the specified pod will come closer to eavesdrop on the evening’s hunting activities. This can lead to an overwhelming presence of humpback whales in one area, and it can quickly cause the available food resources to be depleted there.
How far can a whale be heard?
The “tick-tock” sound that is used for hunting at night, (or in the dark) is very different from the humpback's typical songs, and this is probably done to minimize the amount of attention that is captured from outside the hunting group. The normal call of a humpback whale can be heard from miles away, and they often make noises that sound like crying or moaning.
How much food does a humpback whale consume?
Lots! This is especially true of the humpback whales living in Arctic waters. The massive food needs of each whale in the pod can make it necessary for groups ranging from four to 20 to hunt together if they are going to remain satiated during difficult hunting conditions. When this technique is employed near the surface of the water, it is referred to as “bubble net feeding.” Although the latest information regarding singing is relatively new, it is simply a variation on their more well-known hunting methods.
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