Researchers examined the teeth of 62 whale skeletons, some that were hundreds of years old. They found that “type 1? whales had longer teeth with significant wear in comparison to “type 2.” Type 2 whales fed on a combination of seals and fish. But type 1 whales stuck to dolphins and smaller whales, like that of Antarctic orcas.
“They seem to have occupied completely different ecological niches and have started to diverge morphologically,” said Dr. Andy Foote, of the University of Aberdeen in the UK. “It’s similar to how Darwin’s finches have adapted to different ecological roles in the Galapagos, but on a larger scale.”
As expected, their diets also affected their shape and size. The type 1 whale were a full six feet longer. It also played a part in their color, pattern and how many teeth they actually had.
These findings are important for conservationists as it shows there are two distinct groups of whales which have different diets and may not breed together.
“They seem to have occupied completely different ecological niches and have started to diverge morphologically. This divergence may eventually lead to the two types becoming different species,” said Foote.
It is common for killer whales to have evolved from ecological differentiations but this is the first finding of two different species occupying the same region. If the two continue on the same trajectory, conservation efforts will need to be focused on each group separately, the researchers claim.