Killer whales are wide-ranging mammals with an estimated life span of 50-100 years, meaning that research into their life history and ecology requires long-term studies. In 1970, a census of the killer whale population ranging in coastal waters of British-Columbia, Canada was initiated by the late Dr Michael Bigg. Bigg and colleagues discovered that individual killer whales could be distinguished using the shape, nicks and notches of the dorsal fin, along with pigmentation pattern and naturally acquired markings of the saddle patch. Therefore, by analyzing photographs of surfacing killer whales it was possible to catalogue individuals, enabling a precise count of the population rather than an estimate. This methodology introduced 'photo-identification' as a valuable research tool and a foundation for modern killer whale research. Since then, photo-identification has been used to investigate questions related to social structure, population dynamics and group-specific ecology.

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ID of the whale

Nicks and scars are natural markings, acquired through physical contact with conspecifics and possibly through interaction with fishing gears. Most markings seem to be permanent after 5 years of age, making these features highly reliable for identification of individuals, even over several years or decades. 

Illustration Frédérique Lucas

Long-term killer whale research in Norway was pioneered by Tiu Similä in 1986. Similä maintained a consistent data collection effort in northern Norway from 1986 through 2005, especially during the winter months of high abundance of Atlantic herring in Vestfjord-Ofotfjord-Tysfjord (Lofoten). In addition, Dag Vongraven and Anna Bisther from 1987 through 1996 catalogued killer whales occurring in the wintering (Lofoten) and spawning grounds (Møre) of the herring. In 2002, the winter distribution of the herring drastically altered, with the stock over-wintering in the offshore waters north of Vesterålen. This change occurred over several years, with reduced numbers of herring entering the fjord system each year. This transition resulted in fewer killer whale pods entering the usual fjords, and thus leading to a break of several years in the data collection. During winters of 2007, 2008 and 2013 Sanna Kuningas took over the photographic effort, enabling the update of the former catalogue and ensuring the longitudinal ID-study to continue.      


In 2013, Norwegian Orca Survey (NOS) launched a research effort dedicated to monitoring the occurrence and ecology of killer whales on a year-round basis in Northern Norway. As part of this initiative, NOS started to systematically collect ID-photographs as a logical progression of previous efforts. The resulting ID-catalogue constitutes a real baseline for ongoing and future studies and for the effective long-term monitoring and conservation of the Norwegian killer whale population.

During the last few years interest and curiosity in whales has grown incredibly in Norway. In particular, during the winter months both local inhabitants and tourists enjoy spending time on the water watching and photographing the numerous humpback and killer whales feeding on herring off Troms and Vesterålen. In response to such growing interest and to contribute to raising awareness of this top-predator and its marine ecosystems, NOS decided to make this ID-catalogue public. In addition, this catalogue can be perceived as an invitation to take part in the ID-project. All photographs accompanied with information about the date and location where taken provide extremely valuable data that will serve to expand both the sighting histories of specific individuals and the overall catalogue. In other words, all photographs taken during encounters with killer whales tell amazing stories about them, starting with who, where, when and with who. By contributing photographs to the project, people are getting directly involved in this long-term study and become citizen-scientists. Citizen-science is widely used for the monitoring of diverse animal species in the world. Connecting research and the general public also constitutes a powerful tool for education.

Design D. Vongraven

      After becoming familiar with the work of Michael Bigg in Canada’s Pacific Northwest in 1986, we found ourselves in a small fishing vessel in the fjords just north of Kristiansund, at the northwestern “end” of the southern part of Norway. To photograph and make use of individually recognizable individuals to allow longitudinal long-term studies of free-ranging killer whales was an idea that induced deep fascination in young scientifically oriented minds with a drag towards the ocean and its creatures.

Initially only rewarded by enthusiasm and strong beliefs, we spent days and weeks on the open waters off Møre, the main spawning areas for the Norwegian stock of spring-spawning herring, and slowly our catalogue of “familiar” whales started building. After the herring collapsed in 1970 due to overfishing, the stock started to recover during the 1980s, and found a new winter residence area in the Tysfjord-Ofotfjord system in Northern Norway. Spending winter months in Tysfjord from 1989 and spring and summer months down south, gradually educated us in the art of producing knowledge about killer whales by use of benign techniques. In 1990, we received funding from the Norwegian Fisheries Research Council for the four years 1990-1993, which really launched us into a life dedicated to research on marine mammals.

The work that Norwegian Orca Survey is doing is impressive and solid. It is especially rewarding to see how our old data come to life and make stories in combination with new material. Long-term longitudinal studies of long-living species has shown repeatedly that photo-identification has a high potential for producing basic knowledge about marine ecology – knowledge that is necessary if we want to be able to manage the marine environment in a sustainable manner.


Dag Vongraven

Biologist and senior adviser

Norwegian Polar Institute

      About four decades ago Canadian scientist Michael Bigg and colleagues discovered, while studying killer whales around Vancouver island, that not only could adult male and female killer whales (with a smaller dorsal fin) be distinguished from each other but also that each individual could  be recognized from photographs showing the shape and natural markings on their dorsal fin and saddle patch. This discovery revolutionized studies on killer whale populations around the world.

Identification pictures of killer whale individuals combined with information on the date, where the whale was seen, together with whom, how they were behaving including vocalizations, what the whales were feeding on, which females had calves etc ... gave new insights into the life history, social structure and behavioral ecology of killer whales.

Photo-identification of killer whales in Northern Norway, above the Arctic circle, started in mid 1980's and has been continuing since then. Images taken by hundreds of persons throughout the years have been vital for numerous studies and long-term photo-identification data continues to be at the core of ongoing work.

I was the curator of the catalogue in 1986 – 2005, before Dr Sanna Kuningas took over the catalogue while working on her PhD thesis from 2007 through 2013. A new dedicated PhD student, Eve Jourdain and her organization Norwegian Orca Survey, has undertaken the task of organizing and updating this valuable long term dataset.

I am pleased to see that the catalogue finally goes digital in a form that is accessible for anyone interested in understanding the basics of the method, how the different individuals look like and what we can learn through systematic use of this method. I hope this will be an inspiration for more people to get involved in reporting sightings, taking identification pictures and in general getting involved in following the lives of these extraordinary whales.

Dr Tiu Similä

Whale scientist

The content of this catalogue, including identification images and illustrations, is not to be reproduced or used without permission. 

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