MOST of us have heard of humpback whales, but perhaps not everyone knows about humpback dolphins. That may be because there are so few of them, only about 500 along our coast.
In fact, the humpback dolphin is the most endangered marine mammal in South Africa. Something needs to be done urgently to help protect them, but scientists say not a lot is known about these shy, elusive creatures, so researchers are trying to get more information about them to help guide how best to protect them. University of Stellenbosch PhD student Sasha Dines is doing some of that research right on our doorstep in Mossel Bay. And that is where the tale of the “lost, orphaned or stolen” baby dolphin comes in. Part of Sasha’s research is to identify humpbacks, which she and colleagues do by photographing them (each back fin is unique) but also by identifying the sounds they make, called “signature whistles”. Dolphins use these whistles to communicate with each other, and here is the fascinating thing: each whistle is unique to each dolphin. “It is almost like a dolphin name,” she said. How does she identify the different whistles? She has 24 underwater acoustic recording devices in Mossel Bay that record dolphin whistles day and night over several weeks. Last week, when she and the team were photographing the humpback dolphins in Mossel Bay, they came across something exciting: a newborn baby swimming with the pod. But when they got home and checked the photographs more closely, they saw it was not a baby humpback, but a baby common dolphin. How come it was swimming with a humpback “mom”? The researchers say it is highly unusual, and they have no idea whether the baby common dolphin was lost, orphaned or even stolen. Stolen? I spoke to Sasha to find out more. Apparently there are records of baby dolphins of one species being taken on by another species, possibly because the baby had been abandoned or its mother had died. “But there are also reports of kidnapping, of calves being taken by another species,” Sasha said. I never would have thought that could happen. So what will happen to the little baby? The prospects are not too good. Because it is newborn, it obviously has to suckle from its mom – or a substitute mom – but as far as the researchers have seen, there is no baby humpback in the pod with the “kidnapped” dolphin, which means there is no female with milk to feed it. “To survive it would need to have a lactating female.” But there is a tiny ray of hope. On Sunday the researchers saw a baby humpback dolphin in a different group of humpbacks in Mossel Bay. And if there is a baby humpback in that group, there will also be a mother humpback with milk. But will the two groups find each other? And if they do, will the mother share her milk with the common dolphin baby? “We don’t know. We can only hope,” Sasha said.
