Sunshine and zodiac tours watching transient Orcas - what a perfect start to this Sunday!
The Northern Resident Killer Whale population is the larger of the two resident populations that live off the north Pacific coast of North America. Resident orcas are characterized by having strictly fish diets, large family groups, a complex social structure, and unique vocalizations. It is believed that the Northern Resident community has existed for the past 10,000 to 12,000 years. This period of time has given them ample opportunity to evolve a unique culture and language.
The Northern Residents have a territory that extends the northern half of Vancouver Island up to southeast Alaska. They are most commonly seen during the summer months on the Northeast side of Vancouver Island, through Johnstone Straight, Blackfish Sound and Queen Charlotte Straight. These animals have a picky diet, they prefer to eat chinook or king salmon over any other species. Despite chinook being known for excellent taste, the whales most likely favour them due to their large body size and high fat content, rather than to satisfy a particular palate. The salmon migrate to inland waters, spawning in many freshwater rivers and streams, bringing the whales with them.
The social structure of the Northern Residents is a bit more complex than that of the Southern Residents. The Northern Resident population consists of approximately 200 whales divided into 3 clans named A, G and R. The A,G, and R clans are divided by 16 pods. A pod is a group of closely related matrilines, as killer whales are a female dominated society. A matriline is headed by the eldest female of the family along with her offspring, both male and female, and successively, their offspring. Their are 33 matrilines in total among the Northern Residents. The easiest way to understand this division of groups is by looking at their language. Each pod has a unique dialect of their language, similar to how an Australian, Canadian and British person all speak English, but all sound slightly different. Pods with related dialects belong to a clan, thus there are 3 unique languages among the Northern Residents. Even language in the animal kingdom gets complicated!
The most famous Northern Resident whale has to be A-1, more affectionately known as Stubbs. Stubbs was the first whale identified in the population, thus she was given the alphanumeric name A-1. She earned her common name, Stubbs, because she had a severely damaged dorsal fin, which looked like it had been lobbed off near the base. The most likely reason for this deformity is from contact with a boat propellar, though this cannot be proven. Unfortunately orca have not always been admired by humans, many were shot at or ʻrunoverʻ by angry fisherman or fearful boaters. Luckily attitudes towards these gentle giants have changed, and they have become a symbol of Canadaʼs natural marine environment. As of 2008, the Northern Resident Killer Whale population was listed as Threatened under COSEWIC (Committee On the Status of Endangered Wildlife in Canada), providing protection for the whales, their environment and food sources.
One of the biggest news stories around the world in 2002, was the separation of a young orca calf from its mother and family off of British Columbia and Washington. This orphaned killer whale was A-73 or Springer, a female calf born to Sutley (A-47). Sutley died in 2001, which is likely when Springer got separated from the rest of the pod. She took refuge in Puget Sound, near Seattle, WA, which is far from the northern territory of her community. Springer was a huge attraction and she loved the attention, but people feared her association with humans could lead to her getting harmed by boats. Environmental groups, government and regular citizens alike grew concerned that the calf would not survive long without her family. A mission began, lead by the Vancouver Aquarium to reunite Springer with the rest of the A4 pod. With many biologists, government agencies, non-profit groups, the native community, and financial support from businesses and the general public, Springerʼs reunion was a success and a world first. Springer is now seen every summer happy with her family of aunts and uncles, roaming the waters of northeastern Vancouver Island.
We cannot tell you about the Northern Residents without talking about the rubbing beaches that the whales visit. In the 1970ʼs a small group of biologists lead by Michael Bigg of the Department of Fisheries and Oceans, were studying the Northern Residents. Michael Bigg was the first researcher to discover that each whale could be identified by their unique dorsal fin, saddlepatch and nicks and scars. He began constructing a catalogue of resident and transient orcas. During their many hours of field work, they discovered that the Northern Resident pods regularly visited two areas in Johnstone Straight. These areas were shallow waters (4-8m or 13-26ft), characterized by millions of round stones at the bottom. The orca would come to the area and rub their bodies over the stones, which may serve to remove dead skin. There is no doubt that the whales also love the massage they get from the rubbing! We humans pay big money for that kind of spa treatment! This area was deemed critical habitat for the whales, and the Robson Bight (Michael Bigg) Ecological Reserve was created in 1982 as a whale sanctuary, the first of its kind in the world. This behavior is unique to the Northern Residents, being passed down from generation to generation. The Southern Residents have been observed breaching more often than the Northern Residents, perhaps the breaching serving the same purpose. Also, orca off the Crozet Archipelago in the Southern Indian ocean are known to spend lots of time rubbing against kelp, possibly sloughing dead skin like their distant relatives do in the North Pacific. I guess a good massage is sought after globally by many different species!
The unique differences between orca communities is fascinating. We are constantly learning new things about these incredibly complex and social creatures. It goes to show that there are so many things to observe in nature, even amongst the same species in different areas of the world. Keep exploring!