We witnessed some really interesting behaviour yesterday afternoon in Clayoquot. I've tried finding articles or stories describing similar things, but can't find anything at the moment.
We watched a group of 4 or 5 Steller Sea Lions interact with Sea Otters for around 10 minutes. They would approach at the surface and make a pass around 10 feet from the Otters at first. As the encounter continued they would get closer on the pass. They would then stop alongside the otters, mouth open and "roar" at them. The interaction culminated in them splashing and diving under the raft of Sea Otters.
At first the Sea Otters gave little reaction, but as the interaction drew out their behaviour changed. Once the Sea Lions started roaring a few of the larger Otters were seen to dive under the raft. Once the Sea Lions started to splash and dive the Sea Otters focused their attention on where the Sea Lions were. You can see this in one of the images, where the Sea Lion is diving and all the Otters are facing it.
Sea Lions are known to be curious animals. They approach other large mammals, such as whales. I've witnessed them buzzing around Grey Whales that are attempting to feed. These interactions are often described as a sign of intelligence. The more intelligent you are the more you interact with your surroundings. My feeling is that there was some territorial behaviour involved: the Sea Lions haul out about 200 metres from where the Sea Otters raft. It is likely Sea Lions making clear that it is their patch.
This is one of the best parts of the job - trying to interpret animal behaviour that you've never seen before! Hopefully someone has more of an idea of what's going on than me, or has witnessed it before. Any ideas, anyone?