Social structure in orcas | Norway

January/February 2017

Normally we study orcas topside from a boat and usually a few hundred yards away. Orcas spend most of their time underwater, and only surface to breath and occasionally for play. It's quite difficult to study the social structure and patterns of orcas when you're studying only their surface behaviors. In Norway, we have the amazing privilege of swimming with and studying orcas underwater. In the frigid arctic waters, we can slip below the surface into the realm of the orca. Each year from October to February, thousands of herring take shelter in the Norwegian fjords. Orcas force the herring into bait balls, and carousel-feed. In this unique feeding behavior, the smaller orcas and more agile females swim directly into the bait ball while the large males tail-slap and block the herring from the outside. It is an amazing display of cooperative hunting. In the last 10 years, humpback whales have also taken advantage of this annual herring migration. They follow the orcas into the schools of herring and will lunge-feed up through the herring, taking thousands at a time. In one particular instance, my photographer friend Gary and myself were the only people in the water and had an active bait ball. We separated on either side of the bait ball so we'd have the best chance of witnessing wild behaviors without interference or stress on the animals. The large bull male orcas were patrolling the perimeter, closest to Gary, and a large humpback swam directly underneath me in an attempt to feed.

She surfaced a few feet away from me, and then swam back directly at me. I was most likely interfering with her ability to lunge feed into the bait ball, but I was probably inadvertently aiding the orcas. Sometimes humpbacks can break up a bait ball in seconds, after the orcas worked so hard to herd the herring in the first place. It is an impressive display of two predators coexisting while hunting the same prey species. When they're not feeding, the orcas exhibit playful and resting behaviors. They appear to be quite curious about us, and come closer for a better look. I had two females approach me multiple times, seemingly curious about my dome-housing on my camera. Orcas are self-aware, which means they recognize themselves. I believe they could see their own reflections, and they continued to approach me to "see" themselves. Orcas are highly intelligent and social marine mammals. My best photo, the snapshot of 4 orcas,  shows a very social group: a presumed mother orca, her young calf, another female family member, and a large male. The large male is in the background, a safe distance from me. If he had felt threatened, he would have positioned himself between me and the females. We have also discovered that some dolphins and whales will  show their bellies at us when they are accepting of us (shown in the black & white image of 2 orcas).