Featured Image Credit: Michaela Hanusova
By Jessica Kittel
When you’ve got an itch sometimes you just really need to scratch it. Just ask these killer whales aka Orca whales (Ocinus Orca). As reported on cbc.ca, these Northern Resident Orcas were caught on camera rubbing up along a stretch of rocky shoreline near Sechelt B.C.; a behavior scientists claim is very common amongst this particular subpopulation of Orcas. While it is common for these Northern Resident Orcas, it is a behavior that is not seen in any other Orca group.
As explained on us.whales.org, there are a few different types of Orca groups: Resident, Transient, and Offshore. Each group not only have unique physical attributes that set them apart from the others, they also all have very unique behavioral and feeding patterns. These groups are so distinct that they are not thought to have interbred for upwards of 10,000 years, according to pbs.org. Physically, you can discern which type of orca you’re looking at by their dorsal fin. Resident orcas have rounded tips while transients have pointed ones.
Transient Orcas (aka Bigg’s Orcas) are likely where the “killer” part of “killer whale” was derived. This type of Orca feeds mainly on other marine mammals such as seals and whales. They’re known to eat anything from a harbor seal to a minke whale to a gray whale calf! They live in small familial groups that travel throughout their rather large home ranges that span from Southern California all the way up to the Arctic Circle.
Resident Orcas (the group the aforementioned belly rubbing Orcas belong to) are the slightly gentler breed of Orcas. These are the fish eaters, whose small home ranges tend to center around large fish populations. The different resident populations tend to have a favorite meal, and usually, it’s salmon.
Then there are the offshore Orcas. These are the badass orcas. Due to the fact that they live far from shore (they’re usually found over the outer continental shelf) they are rarely encountered by humans and therefore remain rather mysterious. While we don’t know too much about their social structure or food preferences we do know that they are usually seen in extremely large groups (usually 50 orcas or more). They’ve also been observed eating fish and even sharks! Upon examination, it was noted that their teeth are often worn down suggesting they snack on critters that have rough skin (such as a shark) rather often. Offshore Orcas are the smallest of the three types, which is possibly why they like to hang out in such large groups.
Orcas are the first animals (besides humans) that we know has been evolutionarily influenced by their own culture. What this means is that all the separate orca populations (separated geographically) have developed their own cultures in the form of hunting and socialization systems, as explained on sciencealert.com. For example, while all resident orcas hunt fish, different populations in different areas might have created, adopted, and passed along a different strategy to achieve their desired result. Northern Resident Orcas using the rocks to scratch themselves is the perfect example of this cultural influence.