Orcas most commonly rest in their social groups while swimming slowly (2 knots or less) close together, closely synchronizing their breathing. Orcas also rest quietly while lying almost motionless on the surface of the water, usually with other members of their immediate family close by. They are very quiet during these rest periods, emitting just a few, short, discrete sounds. Resting at the surface may last for a few moments or for quite long periods of time, even hours. It often seems as if one member of the group will remain more attentive then the rest. Sometimes the young calves have difficulty remaining as still as the adults. After a while the frequency of the short calls increases until finally one whale gives a louder “wake up” call. Then the activity within the group will pick up and the group will travel onwards, rest over.
When orcas are “travelling” the group members are all headed in the same direction and are usually distanced not far from each other. Travel speeds vary from about 3 to 12 knots. Sometimes when the group has travelled long distances to reach a desired area there are periods of silence interspersed with periods of intense vocal activity. The Northern Resident Community whales generally arrive in the Johnstone Strait area from the north. As they enter into the Strait they seem to “announce” their arrival to the other whales that are already in the area. These “announcement” calls may have been preceeded by complete silence until the orcas enter into Johnstone Strait proper. When large groups of whales arrive and head into the area there is often a lot of intense vocal activity. At these times there is a great deal of excitement, both for the whales and the human listener alike.
In the summer and fall seasons the whales take advantage of the abundance of the annual salmon runs, so there is a lot of feeding (foraging) behavior. Although orcas generally fish individually, they probably coordinate their movements as a group to maximize their chances for success. The group ( whether it is a small maternal group, several maternal groups or several pods) usually spreads out over an area. Together they will move in the same direction. Quick, brief changes in direction indicate that a whale has located a fish.
In other places in the world, such as Norway, orcas have been filmed cooperatively hunting herring by forcing the fish into a tight ball after startling them. Then, by using their flukes, some whales in the group stun the fish while others take the advantage and feed.
In other places orcas have “pushed” fish into shallow waters to allow other members to feed. Sometimes orca behaviour is molded by the different types of salmon present. Sockeye salmon tend to swim in the cooler depths, which encourages the whales to make longer and deeper dives. The Chum salmon, however, swim closer to the surface in large schools which get caught up in the strong tide rips. In the Fall it is not unusual to see large groups of whales “working” one of these tide rips, spending hours shallow diving, picking off fish one after another. The large Chinook (Spring or King) salmon stake out their own individual areas. They like to be near to the rocky crevices along the shoreline. When the orcas locate one of these fish the chase is on. Sometimes the fish evades the whale and manages to hide in a crack. The whale does not give up easily and will worry over the spot for quite a while, even trying to flush out the fish by undulating his or her body up and down in an attempt to make travelling waves. Other group members may help out by doing a similar movement. Remarkably, orcas suffer very few serious abrasions during these efforts. Occasionally, a whale will even chase a salmon right onto the shore in shallow water and then have to wriggle back into deeper water! The whales may or may not be vocal during foraging, but usually there is some vocal activity as they keep in touch with each other. There is an increase in the use of echolocation clicks as orcas zero in on prey fish.
Orcas are very social animals. During the summer season, when they are observed the most, they spend many hours intermingling with one another… with other maternal groups, with pods from the same clan and with pods from different clans. In the Northern Resident Community, preceding the arrival of a new group, one of the more frequent user groups may leave the area in order to “escort” the new group into the area. As they enter Johnstone Strait the whales often pause in their travel. Other orcas in the area may come toward the arriving groups, and together they may (often after an intense vocal period) all go quiet, rest on the surface and socialize with each other. This latter state may include spy-hopping (where the head is thrust out of the water), rubbing bodies together, full breaches (where the whole whale jumps free of the water), fluke (tail) and pectoral slaps, and deep diving. Sometimes these same behaviors are exhibited by the whales coming to greet the incoming whales, but they calm down when the groups near each other. On these occasions the greeting whales may turn around before the visiting groups and travel ahead of them. Either way, the whales will usually sort themselves into their maternal groups and then all head in the same direction. For the Northern Resident orca, after they resume travelling, they will most likely head for the Robson Bight area and the Rubbing Beaches beyond. These Rubbing Beaches are a unique feature of the area. Though whales have been observed rubbing in other shallow areas, their use of these particular beaches is very consistent and well documented. It seems to be an important part of their traditional use of the Johnstone Strait area. The beaches are covered with small, flat, round and smooth stones. The whales dive, blow out air as bubbles to lessen their buoyancy, and then skim their bodies over the stones. Sometimes several whales will use the beach at one time, but they will also take turns, waiting a short distance offshore for their turn. This activity brings the whales very close to shore. Again, they may or may not be vocal as they are rubbing.