In the last winter, a scientist from British Columbia, Canada, became one of just a handful of people around the world to ever get a chance to lay eyes upon a pod of Type D killer whales, a mammal so rare that scientists in the past have gone decades without seeing them.
The Type D orcas were first spotted in 1955 when a pod washed up on the shore in Paraparaumu, a town 35 miles from New Zealand’s capital city, Wellington.
The pod of whales was quickly identified to be different from the typical Type A killer whales. The 17 animals that were stranded on that beach had very different features, which included a more rounded head shape and a narrower, pointier dorsal fin, with tiny white eyepatches in contrast to the typical larger white patches seen in their Type A counterparts.
At the time, though, scientists were unsure if these rare marine mammals were truly a different species or if they were simply the offspring of a female with “genetic aberrations.”
However, in 2005—almost 50 years later—a research team confirmed seeing killer whales with similar physical descriptors, this time off the coast of the Crozet Islands.
Then, with stories from Chilean fisherman of bizarre Type D killer whales stripping the fish from lines out near Cape Horn, off Southern Chile, it was becoming evident that these unusual creatures were more widespread than initially believed.
One year later, McInnes spotted them again in an expedition where he along with other naturalists made their way to the Drake Passage between South America and Antarctica. However, this time, they gained even more information about the mysterious mammal.
Pitman’s crew in 2019 was able to record the Type D killer whale calls and collected DNA samples, which would help NOAA to determine if the whales were a new species or if they were simply genetic anomalies.
In McInnes’ expedition, though, they observed some behavioral traits that could help scientists understand even more about the elusive creatures.
In addition to noting that the expedition’s discovery was the farthest south of any killer whale sightings to date, McInnes and his crew discovered that the Type D killer whales seemed to be content to intermingle with fin whales, which could suggest that they are fish eaters.
“There was no aggression between the two,” McInnes said. “In other cases marine mammals will show some kind of stress when killer whales are around, particularly if they’re the type of killer whales that forage on marine mammals.”
With very few scientific sightings of the killer whales in more than 65 years, there’s still so much that we don’t know about these fascinating creatures.