By becoming a member of the Wild Killer Whale Adoption Program you will be directly supporting research on wild killer whales. Continuing research will lead to a better understanding of the whales, their place in the ocean ecosystem, and the conservation measures necessary to protect them.

 

The Blackfish Sounder 

Annual newsletter of the Wild Killer Whale Adoption Program

The Blackfish Sounder is the annual Adopters-Only eight-page newsletter of the Wild Killer Whale Adoption Program that is sent to anyone who joins the program by adopting a whale. Through a mix of news and feature stories, The Blackfish Sounder keeps adopters up-to-date on what we currently know about killer whales - in B.C. and around the world - and what we hope to learn in the future. See the article below for a sampling from the 2017 issue.

 

You Are What You Eat 

We are all familiar with the phrase “You are what you eat”, which essentially means if you continue to eat particular foods they will eventually have an effect on your appearance. This concept was the driving force behind a recent study by Charissa Fung, who set out to determine if the diets of killer whales could have an effect on the shape of their skulls.

Three types of killer whales roam the waters of B.C. – residents, Bigg’s (transients), and offshore killer whales. Not only do these types not interbreed, but they behave differently, their calls are different, and they have completely different diets. Resident killer whales exclusively feed on fish, primarily Chinook or even Coho salmon, Bigg’s killer whales prey solely on marine mammals like seals and porpoises, and offshore killer whales will eat some fish but also feed frequently on several species of sharks. With different diets, each ecotype has developed their own foraging strategies to be able to catch and process their prey. The way that their prey are handled may shape the evolution of the cranial morphology of each killer whale type, which is what Fung has attempted to answer in her work.

Fung measured killer whale jaw bones and many different aspects of the skull morphology from standardized pictures of 70 skulls collected throughout Alaska, B.C., and Washington. Each specimen was categorized as one of the three ecotypes by using information collected from necropsies, such as photographic identification and/or stomach contents, or by genetics (see page 7). Then she let the skulls do the talking and patterns began to emerge.

Skulls from resident and Bigg’s killer whales could be correctly assigned to their type, just by their measurements including the width of the skull and the shape of the jaw bone. Skulls from residents and offshores were generally smaller in comparison to Bigg’s killer whales, which may make them more agile and better able to pursue small prey such as fish. Bigg’s killer whale skulls also possessed more deeply curved jaws than both resident and offshore skulls, which is thought to strengthen the jaw and prevent it from bending when holding struggling prey – such as a squirming sea lion trying to get away! Skull morphology in offshore killer whales was much more variable, making it harder to distinguish them by skull shape alone. But again their prey items may have left clues behind on the skull – this time on the teeth! Offshore killer whales commonly prey on sharks, which leave their teeth worn down from the abrasive sharkskin. Overall, it seems that your mother was correct; you essentially are what you eat – at least if you are a killer whale!