22 Marzo 2017 17:52
Humpback whales have developed something of a reputation for baffling the scientific community. A few months ago we told you how marine biologists were scratching their heads trying to figure out why these massive mammals were interfering in killer whale attacks on other species, in an apparently altruistic attempt to rescue the prey.
But now these enigmatic denizens of the deep are once again engaging in behaviour that has scientists stumped. It seems that our humpbacked friends are gathering in huge groups off the coast of South Africa. And nobody knows why.
Humpback whales have always been relatively solitary animals. In fact, until recently, a group of 20 would have been considered unusually large. The aggregations currently being spotted, however, number up to 200 members. They are cetacean armies.
And there's more. Humpback whales migrate to tropical waters to breed, but by this time of the year they should already have returned to the frigid waters of Antartica. So why are they still around? Well, here's a theory: the music festival season is just getting started, so maybe the whales are gathering for some kind of underwater Woodstock... Whalestock anyone?
Most of the individuals making up these groups are young. If they were adults they wouldn't have enough food
Alright, it's a pretty crappy theory, but the scientists aren't doing much better. This is what they know so far: most of the individuals making up these groups are young. If they were adults – which weigh around 30,000 kg – they'd have run out of food by now. Think about it: when 200 blubbery behemoths turn up and decide to hang out for a while, you can't expect the all-you-can-eat buffet to last very long.
Scientists believe that these whales have assembled to hunt and feed together, but no one is sure why they are in such large groups. The phenomenon has been occurring for about five years, so the recent increase in whale numbers could be an explanation.
Whalers decimated the humpback whale population a century ago. At its lowest point, it was calculated that 90% of the world's humpbacks had been killed by man. However, since it was declared a protected species in 1996, numbers of humpbacks have gradually increased. Perhaps they were always this sociable, but there were so few of them that we just didn't realise it.
Another possibility is that we hadn't been looking in the right places. Perhaps hundreds of whales have been gathering for raves in the middle of the Pacific Ocean for years and we just hadn't noticed until now.
[Via Popular Science]