A view of whale behavior and diving patterns over time suggests that they are choosing to go to different depths at different times, but why?
1) Looking at whale diving behavior
Scientists working down in Antarctica attached temporary tags* to humpback whales backs in the fall of 2009. To better understand whale behavior, scientists track numerous whales in-person (from a boat) and by looking at the tag data of where they go when we cannot see them at the water surface.
Let’s learn about how they do this.
*NOTE – All animal-related work in this study was permitted under the U.S. Marine Mammal Protection Act by the National Marine Fisheries Service Permit 808-1735, the Antarctic Conservation Act Permit 2009-014, and Duke University Institutional Animal Care and Use Permit A041-09-02.
2) Reading a whale track plot
Scientists analyze the data where the whales were over time to learn about what they were doing. Scientist look at the depth and the amount time it was there to learn about the whales behavior.
But what might be driving where the whales are going?
3) Reading a krill biomass plot
Maybe they are following the their food source, Antarctic Krill.
Scientists can use multiple pieces of equipment to estimate the krill biomass (how many) and distribution (where they are). Similar to the whales, they can use these data to determine when and where the krill were as well as how much krill was at different depths over time. Together all of this information provides scientists with an idea of amount and location of the krill.
To learn more about Antarctic krill in Antarctica, check out these resources:
Fisheries & Aquaculture Department of UN – Antarctic Krill,
IUCN List of Threatened Species – Antarctic Krill,
Australian Antarctic Division, or
American Cetacean Society
4) Let’s make a prediction!
If whales are following the krill (to eat them)… then where would we expect to see the whales around these krill on this day in May?
Looking at these krill data, where would you expect to see the whales? Use your mouse to click inside the graph where you think a whale would be.
Once you have made your predictions of where you think the whales may be, select “Next →” to go to the next part of this story.
5) Let’s compare!
Looking at the track of a whale on top (overlaid) on the krill data from May 7, 2009 in the same location off Antarctica, how does it compare?
What are similarities and differences between your predictions of where you would see the whales and where the whales actually were?
6) Thinking about the big picture
The whales move with their food. What could happen to the whales if the the location or amount of krill changes in the future? Join in the conversation on our Facebook page!
As the ocean changes with climate change, scientists will study the impacts on individual species as well as the impacts how different species interact in the ecosystem. This is what the Palmer LTER project is focusing on around the Western Antarctic Peninsula.
Interested in learning more about why the whale track looks different at different times?
Extension) Different kinds of behavior patterns
The behavior of humpback whales often falls into four categories:
Extension) Looking at the data!
Throughout the day the whales behavior changed. And so did where you found the krill!
On May 7, 2009, we estimate that this whale spent its time alternating between exploring and feeding. Do you agree? Join in the conversation on our Facebook page!
Kristin Hunter-Thomson (Story Design)
Dr. Doug Nowacek & Dr. Ari Friedlander (Science Advisors)
Lucas Marxen (Interface Development)
Dan Farnsworth (Data Visualization & Website Development)