Younger whales might not be able to find new dining areas if global warming kills off krill, their favorite item on the menu.
Postdoctoral biology researcher Luciano Valenzuela studied skin samples from 131 baleen whales migrating off the coast of Patagonia in Argentina and found that most of them followed their mothers’ feeding patterns.
Valenzuela and U biology professor Vicky Rowntree are concerned that younger whales would be in trouble if krill died off from warmer-than-normal water because they wouldn’t be able to find new feeding locations.
“Just think, if your mom always took you to Crown Burger but your normal restaurants burned down, are you bright enough to go and look elsewhere for food?” Rowntree asked.
The mothers stay with their offspring for one year, teach them where to feed and other useful survival techniques and then leave them to fend for themselves. The younger whales typically go to the same feeding areas and eat the same food as their mothers.
“The animals need to know where to go for food,” Valenzuela said. “We don’t know how they will respond to a lack of food in that area.”
Along with three other U researchers, Valenzuela tracked whether related whales were traveling to the same areas for food and what kind of food they were eating based on food particles in whale’s tissue.
He said the majority of whales went to the same feeding area as their mothers and other relatives.
Previous studies have shown that in areas where krill have died off for one reason or another, mother whales have stopped giving birth to as many calves, Rowntree said.
The mothers give birth during the winter when the weather is poor, and survive by fasting and living on their own blubber.
“It seems like the whales need krill to reproduce successfully,” Rowntree said. “If the krill go, they need to find some other food source. It may take them years to realize they shouldn’t migrate to that area.”
However, Valenzuela said whales might be able to locate new krill locations on their own, but researchers will need to study migratory and food-eating patterns more.
Researchers have already been tracking thousands of whales through a 38-year study near the Peninsula Valdés in Argentina.
Valenzuela has been tracking whales’ eating habits for the past four years during annual trips to collect samples. She said she wants to expand the study.
“We’re focusing on trying to understand if there are more animals dying after a climate event like El Niño,” Valenzuela said. “If they are bigger or skinnier and how the climate change affects them.”
Researchers also plan to track whales using new markers imitating a GPS system that would monitor whether whales stay in certain areas or migrate to other places for food.
“Some reports saying 95 percent of krill around the Antarctic will be gone in 100 years,” Rowntree said. “We need to know if the ones dependent on krill will go to another place.”
John AtkinsonYoung baleen whales could face difficulty finding food if global warming destroys krill that lives in the whales? traditional feeding areas.