Monday, March 18, 2013

Strandings Not A Family Affair

As we continue to study whales, we understand a little more about their complex social strata.
Er...that is, scientific study, not the supposed "research" carried out by Japanese butchers!
ABC Science reports a new DNA study of long-finned pilot whales stranded in Tasmania and NZ questions a long-held belief, that whales beach themselves while attempting to save members of their family. Scientists previously thought healthy whales were drawn into shallow water trying to support sick or disoriented family members. But the new study, in the Journal of Heredity, found stranded groups were not necessarily members of one extended family.
Marc Oremus, University of Auckland: "If kinship-based social dynamics were playing a critical role in these pilot whale strandings, we'd expect to find that the individuals in a stranding event are all related to each other. We'd also expect that close relatives, especially mothers and calves, would be found in close proximity to each other."
Long-finned pilot whales (the ones regularly massacred by Faroe Islanders) are the most common species to mass-strand. DNA was analysed from 490 whales in 12 beachings, the largest involving more than 150 whales, all of which died. The position of the whales was also mapped to find out whether animals found near each other were related. Typically they were not. Even nursing calves and their mothers were often widely separated, while many mothers were missing from the groups altogether. Oremus: "The separation of related whales might actually be a contributing factor in the strandings, rather than simply a consequence."
The research team says the study has implications for rescue efforts of beached whales. They're cautioning against attempting to refloat calves with the nearest mature female under the assumption that it is the younger whale's mother.

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