The humpback whale population has described a ‘U’ due to human activities, as these graphs suggest.
Source: Maui Whale Watching
Our ability to monitor whales before their tremendous population crash was infinitesimal, of course, so biological questions concerning their behavior in large numbers remain largely unanswered.
Source: ESA Success
But for how much longer? NewScientist (18 March 2017) reports on, well, the beginnings of big parties:
IN A baffling change to their behaviour, humpback whales are forming massive groups of up to 200 animals. No one is quite sure why yet, but it could be their long-lost natural behaviour when population levels are high.
Humpbacks aren’t normally considered to be terribly social. They are mostly found alone, in pairs, or sometimes in small groups that disband quickly.
But research crews have spotted strange behaviour on three separate cruises in 2011, 2014 and 2015, as well as a handful of public observations from aircraft. These super-groups of up to 200 were spotted feeding intensively off the south-west coast of South Africa, thousands of kilometres further north than their typical feeding grounds in the polar waters of the Antarctic (PLoS ONE, doi.org/b33z).
