Narwhals are mysterious marine mammals that amaze us with their unusual appearance and secretive lives under Arctic sea ice.
Yet while we still have a lot to learn about narwhals – including how to save some endangered populations from ourselves – scientists have also made a few key discoveries in recent years.
The narwhal is well-known for their remarkable deep dives to almost 2 km (1.2 miles) below the surface. They also depend on sea ice to sustain their life cycle.
Researchers have been able to uncover what appeared to be irregular daily behavior of narwhals near East Greenland’s coast, thanks to chaos theory.
”While animal-borne ocean sensors continue to advance and collect more data, there is a lack of adequate methods to analyze records of irregular behavior,” “Evgeny A.Podolskiy is a geoscientist at Hokkaido University in Japan, and the first author of this new study.
In hopes of rectifying that, Podolskiy teamed up with Mads Peter Heide-Jørgensen, a marine biologist at the Greenland Institute of Natural Resources, to develop a new way of finding patterns in the seemingly haphazard habits of narwhals.
Chaos theoryThe study of activity that seems unpredictable but is still governed by strict rules.
It’s like a butterfly that kick-starts a hurricane by flapping its wings. It’s all about dependable physics building up in ways that no system can track.
Like many animals, the narwhal’s wanderings don’t make it easy for us to understand their day.
A satellite-linked time-depth recorder attached at the animal’s back recorded an adult male narwhal’s movements for a period of 83 days. This provided new insight into narwhal behavior.
Combining their respective specialties in signal processing and biology, Podolskiy and Heide-Jørgensen developed a method that uses mathematical tactics borrowed from chaos theory to make sense of chaotic behavior in dynamic settings.
The researchers explain how these techniques can uncover hidden states, called “attractors”, toward which chaotic systems tends develop.
These can be used to help scientists identify patterns in complex processes such as cryptic behavior of narwhals.
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The tools of chaos theories helped to uncover a hidden daily pattern that this narwhal followed, as well as novel details about how these habits could be affected by seasonal changes.
Here’s the result: The tagged narwhal tended towards the surface during the day, but when he dived, he went down especially deep.
Researchers report that dives at night and twilight occurred in shallower water, but they were also more intense. This could be because the narwhal was looking for squid.
The study also found that the narwhal’s patterns were affected by the presence of sea-ice.
The researchers found that he displayed intense diving behavior and reduced his surface activity when sea ice was greater.
The IUCN does not list Narwhals as an endangered species. International Union for Conservation of NatureThey are however still vulnerable to human activities like ship traffic or water pollution. Climate Change. Some populations are at risk of disappearing.
Sea ice is rapidly disappearing due to global climate change. Understanding their behavior can help protect them.
Researchers write that Chaos theory could also be helpful in the analysis of animal behavior more broadly.
This approach may help us to understand the difficulties faced by Arctic wildlife because of rising temperatures and diminishing sea ice. However, it is still very early.
Because the new study only focuses on one individual’s behavior, it will require more research (and more Narwhals).
The researchers note that it covers “an unusually long time” of nearly three years, despite the fact that similar records typically only cover a few weeks.
“Our approach is fairly simple to implement.” The authors explain.“And can map and label long term data, identifying differences in the behavior of different species and also detecting perturbations due to changing influences.”
The study was published by PLOS Computational Biology.
