The short answer is yes, and no. Killer whales are one of the most widespread mammals on the planet. They exist in every ocean, yet each population has a unique diet and social structure, making them separate ecotypes.

These differences (especially diet) result in a variety of migratory strategies. Some engage in seasonal journeys, and some do not.

For example, Southern Resident killer whales are what we would call seasonal migrants. Their movements are tightly linked to the journeys of Chinook salmon, their primary prey. The whales go where the salmon go. Historically, the Southern Resident killer whales have spent their summers in the Salish Sea when Chinook salmon make their way to the Fraser River in Canada to spawn. Sadly, over the last 8 years or so, the Southern Resident killer whales have been forced to adjust their migratory patterns because there are not enough Chinook returning to the Salish Sea to sustain the whales all summer long. Their once-predictable migration has morphed into a seemingly desperate movement pattern in which Southern Resident killer whales travel wherever they can find food.

Bigg’s killer whales (“Transients”) on the other hand, can now be found in the Salish Sea during all months of the year. These killer whales are a separate ecotype from the Southern Resident killer whales and feed exclusively on marine mammals of which there are plenty in the Salish Sea. The name “Transient” was chosen for this ecotype because until recently, they rarely spent much time in the Salish Sea. Now, different families of Bigg’s killer whales can be seen nearly every day by observant boaters and residents. Due to an increase in their primary prey species, they have adjusted their movement strategy and now more time in the Salish Sea and surrounding region all year round. Some matrilines are in the region so much they are considered more or less residential.

In summary, both Southern Resident killer whales and Bigg’s killer whales have “home ranges,” through which they travel. Currently, Bigg’s are traveling far shorter distances than the Southern Resident killer whales, because there is plenty of food available to them in concentrated areas within the Salish Sea. However, migratory pathways are not necessarily static, as Bigg’s killer whales have exemplified. The migratory patterns of killer whales may continue to shift as human decisions alter the availability of food and the quality of habitat.

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