Mama whales teach babies where to eat

Washington, Feb 9 : Biologists at the University of Utah, US, have discovered that young "right whales" learn from their mothers where to eat in the seas.

The new study used genetic and chemical isotope evidence to show that mothers teach their calves where to go for food.

"Southern right whales consume enormous amounts of food and have to travel vast distances to find adequate amounts of small prey," said study coauthor Jon Seger, professor of biology at the University of Utah.

"This study shows that mothers teach their babies in the first year of life where to go to feed in the immensity of the ocean," he added.

The study tracked how whales are related by analyzing maternal DNA, and then compared that with dietary information obtained by characterizing different forms or isotopes of chemical elements in their skin.

The two techniques, which the researchers say they used together for the first time, allowed the scientists to determine that whale mothers, their offspring and other extended family members eat in the same place.

According to Luciano Valenzuela, a postdoctoral researcher in biology who led the study as part of his doctoral thesis at Utah, "North Atlantic right whales feed in similar patterns and scientists have access to their feeding areas, but we don't know where South Atlantic whales are feeding, so we had to use a combination of techniques to track this down."

Rather than searching for right whale feeding grounds visually, the scientists took a novel approach.

During September and October of 2003 through 2006, Valenzuela collected small skin samples using a punch device that doesn't harm the animals.

From the skin samples, Valenzuela analyzed mitochondrial DNA, which is inherited only from the mother.

The DNA revealed family relationships among whales. The researchers were able to distinguish individual whales by the patterns of whitish, callous-like material on their heads.

The skin samples also were analyzed for different forms or isotopes of carbon and nitrogen.

The isotopes, which are present in food, are deposited in different tissues of the body after consumption. Food from any given location has a unique isotope "signature."

That made it possible to determine which whales fed in the same place without actually knowing where the feeding areas were.

Together, the DNA and isotope data revealed which whales were related and where each animal fed.

"The main result is that individuals from particular families have very specific isotope pattern showing that animals from specific lineages feed in the same area," Valenzuela said. (ANI)

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