ORLANDO, Fla., Dec. 10, 2013 /PRNewswire/ -- New research conducted at SeaWorld® aims to help scientists answer a long-standing question: What is the resting metabolic rate of a killer whale? The answer to this seemingly basic question may upset conventionally held beliefs about the impact of killer whales, an apex predator, on their environment, and help biologists make more informed management decisions for endangered killer whales in the wild.
Scientists from Hubbs-SeaWorld Research Institute and SeaWorld worked with Tilikum, a killer whale at SeaWorld Orlando and the largest marine mammal living in a zoological park, to obtain the whale's basal metabolic rate (BMR) by measuring his resting oxygen consumption rate. BMR is an indirect measurement of the energy an animal requires to sustain itself in a resting state. To collect the data a flow-through metabolic dome was placed over Tilikum's blowhole to measure how much oxygen he extracted from the incoming air. SeaWorld training staff worked with Tilikum three months prior to the study to ensure he would be comfortable with the dome.
"The study of energetics in marine mammals, particularly killer whales, is central to our understanding of the animal's role in its ecosystem," said Dr. Graham Worthy, Hubbs-SeaWorld Research Institute scientist and the study's principal author.It all boils down to how the animal keeps its internal "furnace" burning. "If a whale or dolphin requires more energy to live than their land-based counterpart, then we would expect them to eat more." Previous mathematical models have estimated that large dolphins, like killer whales, require a metabolic rate that is double that of an equal sized land mammal in order to survive in the cold ocean. "Our study suggests that is not true. Killer whales appear to have a metabolic rate that is the same as would be expected for a land mammal of equal size."