Like every year now for nearly two decades, whale watchers have been gathering in Polynesia to enjoy the nautical ballet offered by dozens of humpback whales. Recently, the population of these exceptional marine mammals has considerably increased between July and October, mostly in the Austral Islands. This phenomenon is perhaps due to the increasingly respected ban on hunting, but also to the conditions found here by the whales: ideal water temperature, varied and abundant source of food, and reinforced safety to recover from their long migration and to give birth to their calves. After swimming for around 6,000 km (3,700 miles), groups of whales gather around our friendly islands. Staring in July and August, they head north to Tahiti and the Leeward Islands. But starting in September, they go back further south, namely near Rurutu. Presently, there are between 400 and 500 whales during this period, an exceptional quantity compared to 20 years ago.
Thanks to Tahiti Guide – http://www.tahitiguide.com/@en-us/3/88/850/article.asp for this great article.