Migrating Naturalist: Pseudorca

Humpback flukes with orca rake scars are common, as the predators will preferentially attack calves. (The above image was taken under NOAA-Fisheries Permit #587-1767-01)

Most of you have probably heard of Killer Whales, also known as Orca, those charismatic black and white top predators of the sea. They are often a highly popular request from whale watching guests in Tofino, and if you’ve been out with West Coast Aquatic Safaris, you may have already had the chance to view some of the transient pods that will occasionally visit Clayoquot Sound. Orca are highly social animals, whose intelligence and skill in hunting is equalled by none. However, you may not have heard of pseudorca, their smaller, slender grey cousin, which are also known as false killer whales.

Pseudorca crassidens was named in an interesting fashion, when a scientist made the observation that the skulls of orca and pseudorca are nearly identical. Because of this they were granted the “false” name, likely a reflection of the fact that they bear little physical resemblance to the orca. False killer whales are generally quite rare, especially in Hawaii, where the population has dwindled to under 270 individuals. In fact, this stock is currently in the process of being upgraded to endangered status in the United States. The largest influence on the pseudorca decline has come from the fishing industry, as they are often taken as bycatch, and also pose competition to humans for many fish species.

At the Hawaii Whale Research Foundation, we do have the capacity to observe non-humpback groups of interest, particularly dolphins and pseudorca. Last year we had the luck of observing a group of 13 pseudorca as they cruised along off the coast of Lana’i, accompanied by a bottlenose dolphin and even two humpback whales (a rare sighting indeed!).

And so, when we received reports late this morning of a pod with approximately 40 pseudorca moving North along the Maui coastline, my heart leapt with excitement. We quickly finished the observation we were making just off the North tip of Lana’i, and began motoring our way across the channel towards Maui. Unfortunately, the group was lost by its observers as we were crossing, and we were unable to locate them once we arrived in their anticipated area. We picked up a calf group as a consolation prize, but suddenly, another call came in that the pseudorca had been spotted much farther North than where we had expected. We zoomed North along the Maui coastline at top speed, but unfortunately, the wind had picked up considerably, and we were cruising straight into the wind and spray. By the time we reached their area we were soaked with salt water, and the pseudorca had been lost in the wind chop. We were forced to concede defeat this time, but nonetheless it is a great sign that such a large pod was sighted, especially at such a crucial time for the population.

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