New Research Sheds Light on Why Whales Beach Themselves
New Research reveals that genetics or family 'care giving' theories do not play a part in why whales beach themselves.
A recent study, led by Marc Oremus of Auckland University in New Zealand, examined the DNA of almost 500 beached whales. The genetic data revealed that the 'care-giving model of beaching,' where whales are thought to follow a sick or distressed member of the pod in to shore, is no longer valid. Oremus comments: "If Kinship-based social dynamics were playing a critical role in these pilot whale strandings, we would expect to find that the individuals in a stranding event are, in fact all related to each other."This was not the case. Furthermore, the researchers discovered that even mothers and calves, which possess the closest of bonds in the whale family, were not found together either. Even nursing mothers were often found at vast distances from their calves, if found at all.
Co-author of the research, Scott Baker, commented that other long held beliefs on causes of beaching are also invalid. The theory that whales can become disorientated and confused about slope and depth is now refuted.
Baker, associate director of the Marine Mammal Institute at Oregon State University, instead proposes a new hypothesis: "We think there might be competition between the groups or some sort of disruptions prior to stranding."
While the cause of the disruption is still unknown, it's effect is the dispersion of the pod. The study goes on to speculate that distress calls from pod members may be creating confusion in the pod, resulting in their separation when beached.The most common whale to beach itself is the long finned Pilot Whale. Scientists attribute this to the species particular social behaviour. Unlike other whale species, male & female Pilot Whales both remain in the pod they were born in, which is known as a matrilineal social organisation.