Scientists have spotted humpback whales gathering in large groups, a behavior never been seen before in the massive mammals.
A team of researchers working off the coast of South Africa noted this pattern while working in the Benguela Upwelling System, a stream of ocean currents that flow from St. Helena Bay to Cape Point. There, the scientists recorded groups of over 200 whales in 2011, 2014, and 2015.
These sightings contradict previous studies on the massive mammals. In the past, humpback whales have been known to be solitary creatures that enjoy spending their time alone. In some rare cases, the animals have been noted gathering together in arctic waters, but those groups were much smaller than the ones found off of South Africa.
Before this new research, scientists were surprised to find any whale groups larger than 15 members. So, seeing “supergroups” of 20 to 200 of the mammals is a huge shock.
In addition, the sightings occurred in October and November, which is normally when humpbacks have already moved to colder regions to find food for the summer.
“No such dense feeding aggregations have been reported elsewhere in low or mid-latitudes during Southern Hemisphere humpback whale migrations,” said lead author Ken Findlay, from the Cape Peninsula University of Technology in South Africa, in the study published in the journal PLOS ONE.
Scientists are not sure what makes the whales gather in this way. Some postulate it could be due to a large abundance of prey in the Benguela System, while others think it could be the result of population spikes, which could cause the whales to explore new hunting territory. There is also a chance that the animals are reverting to old hunting strategies now that their populations have replenished over the past 20 years.
“For the last few decades, suddenly they seem to have overcome some threshold and have begun to increase very fast,” said Gísli Vikingsson, a researcher at the Marine and Freshwater Research Institute in Iceland, who was not involved in the research, according to Tech Times.
Researchers plan to continue to study this new behavior to see what it can tell them about whale society and migration patterns.