Humpback whales are known to be loners. The gigantic creatures are usually spotted by themselves, in a pair or very small groups that more often than not split up after a while.
In a paper published in the journal Plos One, researchers analyzed the strange and intriguing behavioral shift of these wild creatures. As Gísli Vikingsson, head of whale research at the Marine and Freshwater Research Institute in Iceland, said in a report from New Scientist, it's unusual to find massive groups of humpback whales.
So it came as a surprise to scientists when large gatherings of the creature were discovered in separate occasions in 2011, 2014 and 2015. There have also been several public observation from aircraft.
These super-groups were found feeding together by the south-western coast of South Africa. Even the location is a deviation from their regular behavior, since humpback whales typically feed thousands of miles away in the Antarctic, where they spend summer months gourging on krill.
Although scientists are not certain about the reason for the whales' change in behavior, there are several suggestions. One could simply be the availability of prey in the regions.
It could also be their natural behavior, and their recent population spike could have allowed them to once again indulge in very large gatherings -- and be visible to humans.
"I've never seen anything like this," Ken Findlay, lead author of the study from the Cape Peninsula University of Technology in South Africa, said. "It's possible that the behaviour was occurring but just not where it was visible. Because there were so few of them, we may not have seen it."
The humpback whales have experienced a rebound in population, according to the National Oceanic and Atmospheric Administration (NOAA). Nine out of 14 identified population segments are no longer in danger of extinction or endangerment in the near future, while the West Indies and East Australia populations are experiencing a steady growth rate of respectively 3.1 percent and nearly 11 percent annually.