Some humpback whales are starting to gather in larger-than-usual groups, but scientists aren't sure why, according to a new study published earlier this month.
Typically, these whales are considered solitary mammals, traveling alone, in pairs or temporarily in small groups. Scientists normally call groups of up to 20 humpbacks “small,” according to the study published in PLOS One.
So when groups of 20 to 200 whales began to gather off the coast of South Africa, scientists were shocked.
“I’ve never seen anything like this,” Ken Findlay, the lead author of the study that described the unusual whale behavior, told New Scientist.
The study, which gathered data from three occasions in 2011, 2014 and 2015, pointed out that the whales were in a peculiar location to begin with. Typically, humpbacks migrate to warm waters to breed in the winter and feed in colder waters near Antarctica during the summer. But they were found in the summer months off the warm waters of South Africa.
Regina Asmutis-Silvia, biologist and executive director of Whale and Dolphin Conservation, said it’s hard to say just how unusual the new study’s super group is. She was not involved in the new study, but she has studied whales since 1990. Asmutis-Silvia has seen scores of whales in Cape Cod, and said the large gathering in South Africa might be a result of cultural learning among the whales of that region.
“This is a novel feeding technique for South Africa that hasn’t been seen before,” she said. “It could be indicative of some cultural shift in that population of humpbacks.”
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Large groups of whales tend to indicate areas of the ocean that are rich in prey. The 200-whale groups have exhibited clear signs of feeding behavior, according to the study. Scientists who conducted the study say that reasons for the abnormal behavior remain “speculative.”
Despite heavy whaling that has previously endangered the species, humpback whales have made a strong comeback in recent years.