Killer whales: Culture, communication and conservation of West Coast Orcas
By John Ford, Marine Mammal Research Program, Conservation Biology Section, Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, B.C.
Although killer whales range throughout the worlds oceans, nowhere are they more frequently found, observed and studied than on Canadas west coast. Once feared and persecuted, orcas are now a revered icon of the wild marine environment in British Columbia, and the focus of a multi-million dollar whale-watching industry. Killer whales have also been the focus of intensive scientific study. From this research, a remarkable story of an innovative, adaptable, highly social and communicative predator has emerged.
Our scientific understanding of killer whale life history began in the early 1970s, when Dr. Michael Bigg and his co-workers at the Pacific Biological Station on Vancouver Island began a long term study of killer whales. Mike Bigg developed an innovative field technique he took photographs of nicks and scars on the whales dorsal fin and back and used these markings to identify each individual animal.
By 1975, Mike and his colleagues had discovered that the typical travelling group known as a "pod" is a stable collection of 10-20 related animals, including adult males and females, sub-adults, and young calves. A number of these pods were encountered frequently during the summer months in predictable locations, and thus Mike called them "resident pods." Occasionally, however, they would encounter small groups of unfamiliar whales, often in unusual locations outside the regular travel routes of the residents. These small groups never mixed with the larger resident pods and, thinking that they were perhaps social outcasts just passing through the range of the residents, Mike called them "transients."
In the 25 years that have passed since residents and transients were first recognized, ongoing field studies have revealed a most remarkable picture of these two forms of orcas. Rather than transients being outcasts or rejects from resident pods, the two are entirely distinct populations that exist in social isolation in the same waters. Residents and transients differ in striking ways their social structure, range, genetic structure, vocal patterns, and especially their diet. These differences appear to represent cultural traditions and adaptations that have evolved over millennia, with the whales becoming increasingly specialized to entirely different hunting lifestyles.
The principal difference between residents and transients is their diet. Residents eat squid and fish, especially salmon, while transients evidently shun these types of prey in favour of marine mammals, such as seals and porpoises, and seabirds. This situation where two separate populations of a single species occupy the same habitat and have such divergent food preferences has never been observed in any other mammal.
The rich cultural traditions that have evolved in killer whale societies are among the most advanced seen in any non-human mammal. In their underwater vocalizations, for example, the whales have developed remarkably complicated systems of dialects that serve to identify family groups, prevent inbreeding within pods, and provide for sophisticated transfer of important "real-time" information. Although the whales communication patterns do not yet represent a human-type language, they are clearly headed in that evolutionary direction.
Just as we have begun to accept and better understand this very unusual resident/transient situation on the west coast, over the last few years we have discovered yet another, evidently distinct, population of killer whales in the region. This population seems to spend its time off the outer coast, and hence we have called them "offshores." These whales appear to have a smaller body size and rounder dorsal fin than residents or transients, they live in big groups of 50 to 100, they range widely, and we dont yet have any idea of their diet. In many ways, the recent discovery of offshores highlights the fact that there is still much to learn about this remarkable species.
Despite the protection and reverence that orcas enjoy today, their future on Canadas west coast is by no means secure. Competition for dwindling fish stocks, particularly salmon, is making it harder for resident whales to "make their season" during the summer and fall migration, so they may not be accumulating fat reserves to make it through lean times during the winter. Industrial contaminants accumulate up the food web, ending up concentrating in the blubber of killer whales, especially transients. Even whale-watching may be detrimental to the whales. At times, resident pods may be surrounded by over 100 whale-watch boats, and it seems intuitive that this commotion must be disrupting to the whales. Underwater noise from these vessels and other ship traffic along the coast may well be interfering with the whales ability to communicate and use their echolocation for finding food and navigating.
We are now entering a new phase in our relationship with the orcas of British Columbia. We have gone from persecution to adulation of the species, but now we must focus on conservation. The southern community of resident killer whales has recently been listed as Endangered in Canada. Although scientific studies will continue to reveal more about their natural history and behaviour, more and more we must direct our research efforts towards finding solutions to the various impacts we are having on the whales and their habitat. Only through a solid foundation of knowledge can we identify conservation issues as they develop, and take the necessary steps to mitigate them. With dedicated hard work and political will, future generations will be able to share in the thrill and wonder of experiencing killer whales on the wild west coast.
Thursday, March 27th, 7:30 p.m. MY Place John Ford: "Killer Whales: Culture, Communication and Conservation of West Coast Orcas." See the article above for an overview of Dr. Fords talk. Doors open at 7 p.m. Admission by donation.