As described in a Wild Whales post last June, the long-term, systematic study of killer whales in British Columbia and Washington State is based on the identification of individual whales from photographs that show the unique and recognizable markings of each animal. Photo-identification of killer whales in BC, which started in 1973, continues to this day and has allowed researchers to understand the life history, genealogy, social structure and distribution of these animals. Learn more about photo-id here.

This week, a new identification catalogue of northern resident killer whales was released by Fisheries and Oceans Canada. The catalogue, created by Graeme Ellis, Jared Towers and Dr. John Ford, compiles identification photos of living members of the northern resident population and is organized into matrilines, showing the genealogy of these family groups. The catalogue is a great resource for researchers and avid whale watchers alike, and is available to the public here.

In the technical report that accompanies the catalogue, Ellis, Towers, and Ford reveal that at the end of the 2010 field season, the population was composed of the 3 clans (A, G, R), 16 pods, and 35 matrilines, with 261 individuals alive (plus four missing and possibly dead). This represents a doubling of the population since the mid-1970s, when this population (along with the southern resident populations) was significantly depressed due to capture for live display and intentional shootings.

This long-term population monitoring through photo-ID has been an essential tool for understanding killer whale populations. Most importantly, as stated in the technical report, with each year of monitoring we have an improved “ability to detect subtle changes in these parameters that may result from anthropogenic threats”. This understanding is crucial in the continued efforts to protect and recover this threatened population.