British Columbia is one of the most biodiverse regions in the world, and we are lucky to have three ecotypes of killer whales in BC’s waters: Resident, Bigg’s (Transient), and Offshore. The Resident ecotype is split into the Northern Resident Killer Whales (NRKWs) and the Southern Resident Killer Whales (SRKWs). Each group has its own distinct site fidelity, which helped give them their name!
The Northern Residents, akin to their Southern Resident counterparts, have a fish-based diet, predominantly favouring salmon. Furthermore, they prefer Chinook Salmon, Spring or King salmon, while Chum salmon holds a close second. Together, these make up over 90% of their diet. The remainder of their diet consists of other fish and cephalopods. Their taste for Chinook is why conservation and preserving Chinook in local waterways are crucial to the survival of both the Northern and Southern Resident Killer Whales. The Southern Resident Killer Whales are endangered, while the Northern Resident Killer Whales are not considered endangered and are a delight to see near Telegraph Cove. Even though the Northern Residents are not technically endangered, they also suffer from a decline in the salmon population, like the Southern Resident Killer Whales. They go to their summer feeding grounds in late July and early August and will stay in the Johnstone Strait area throughout the early Fall.
Though it may be difficult to see the differences between these different ecotypes of orcas to the untrained eye, there are some physical differences between the ecotypes that you can spot! Resident orcas are more likely to have what is known as an “open” saddle patch, which means that at the base of their dorsal fin, the grey patch may have swirls of black within it, and come in a variety of shapes, rather than being an entirely grey patch like the Bigg’s orcas have. Their dorsal fins also have some noticeable differences: Residents tend to have more rounded dorsal fins, while Biggs tend to have sharper, more triangular ones.
Another main difference between the Bigg’s Killer Whales and the NRKWs is that their family groups are split into three main acoustic clans, A, G, and R, with the A clan being the largest and most commonly sighted in Johnstone Strait. These clans are then broken down into pods and matrilines – family groups led by a mother or grandmother. While most offspring stay with their mothers for life in the Resident communities, we see greater offspring dispersal in the Biggs’ population.
The Northern Resident Killer Whales exhibit a distinctive behaviour exclusive to their population. They gather along beaches, using soft stones to rub against their bodies while engaging in social interactions. This phenomenon is often accompanied by tail slapping and close physical contact, highlighting their unique social dynamics. The most well-known rubbing beach is in the Robson Bight Ecological Reserve. The Northern Resident clans all have individual vocalizations and can be heard during this activity as they become very vocal and active. This active vocalization is another thing that sets them apart from the Bigg’s orcas, known for being stealthy and much less vocal – until they meet up with other families or partake in a successful hunt!
From May to September, our tours often spot killer whales. We’re dedicated to safeguarding killer whales through passenger education and partnerships with local organizations focused on research and habitat preservation. Join us in making a difference for the future of these magnificent creatures in our waters!
