June is Orca Awareness Month
Do you know the difference between resident and transient orcas?
June 2017 is Orca Awareness Month - let's get to know them better! Do you know the difference between resident and transient orcas? Don’t feel bad if you don’t as researchers only discovered this distinction in the late 1980s. Their diet, morphology (shape), communication, and even genetics are different. Residents and transients have been evolving down separate genetic pathways for the last 700,000 years! Residents only feed on salmon, while transients prey on marine mammals, such as harbour seals, sea lions, small whales, and dolphins. Residents have a very diverse acoustic repertoire and family dialects, while transients have very few calls across the coast. Transients also hunt more in silence and in smaller groups to take their prey by surprise. Different threats such as high levels of toxins (the most polluted marine mammal on the planet!) and chronic underwater noise caused by shipping traffic are affecting their survival...
There is still a lot we don’t know about orcas, such as their movement patterns and habitat use during winter on the central and north coast. We are using a network of underwater hydrophones throughout the central coast to help fill these gaps so that their habitat can be protected.
Click here to help Pacific Wild to learn more and protect orcas’ critical habitat by donating to the Great Bear Sea Hydrophone Network.
Click on this photo to listen to a Northern Resident Killer Whale in a "Orca Hydrophone Visualization" made by our team using underwater seascapes recorded by our hydrophone network.
In the article "Bigg's Orcas Not So 'Transient' Anymore," writer Jared R. Towers reviews the work of researches led by Dr. Michael Bigg, a marine specialiest with DFO. Using photo-identification techniques has resulted in surprising discoveries between the difference of transient and resident killer whales, including the ecological roles exhibited, size and shape, vocalization behaviours, and even a difference in their feeding habits. After conducting research on the acoustic differences between the two, biologist John Ford determined that Resident populations had diverse acoustic repertoires with distinct family dialects, most Transients did not share the same repertoire of calls. Read the full article to learn how the final determination between these populations came about when genetic science enabled biologist Lance-Barrett-Lennard to verify that Transients and Residents are indeed genetically different!
World Ocean's Day Blog post & video