While Northern Resident killer whales are similar in social structure and biology to Southern Resident killer whales, they are genetically distinct separate populations. While their ranges overlap, they are rarely observed together. The Northern Resident population is much larger than the Southern, composed of 34 matrilines and more than 200 individuals.
Northern Resident orcas are similar in appearance to other orcas and can be identified by unique saddle patches and dorsal fins. All Northern Residents are salmon eaters. Like the southern resident orcas, they strongly prefer Chinook salmon over other species, and will hunt it selectively.
Resident orcas forage together and practice prey-sharing; sharing what they catch with other pod members.
Northern Resident orcas live in tightly bound family units called pods, and stay with their mothers and siblings for their entire lives. Generations stay together in matrilines, organized around the older females.
Acoustics. Northern Residents are organized into three acoustic clans: A, G, and R. Clans consist of multiple matrilines that share a distinct set of calls. Each matriline further shares a set of calls. By listening to the calls, trained researchers can identify which pods are in the area and can even identify specific members of a pod.
Rubbing Beaches. Northern residents routinely visit the rubbing beaches of Robson Bight (Michael Bigg Ecological Reserve) during the summer. Pod by pod, the whales enter the shallow waters of the Bight, and roll around or “rub” on the smooth stones there. Scientists believe these areas and behaviors are critical to Northern Resident social structure.
Northern Resident orcas are currently listed as Threatened in Canada. Threats include lack of prey, toxin accumulations, and vessel impacts, including the threat of oil spills.
HOW TO SPOT
Northern Resident Orcas are similar to the Southern Resident Orcas in appearance. They are large black on the back and white on the belly animals. They can have open grey saddle patches and curved (towards the back) dorsal fins. The easiest way to spot these whales is to find the large male dorsal fins. The blows are low and bushy. Look for blows and dorsal fins at the surface.
WHEN AND WHERE TO SEE
This group is most frequently seen around northern Vancouver Island in the late summer/ early autumn.
These whales can be spotted from shore along their range, especially along the central and northern B.C coastline and inlets.
RANGE
Northern Residents range from Southeast Alaska to northern Vancouver Island and in the inlets of B.Cs’s central and north coasts.
BIOLOGY
Northern Residents feed on salmon, primarily on Chinook. They use echolocation to locate the prey.
ADULT MALE FACTS
Male Northern Residents have large (up to 2 meters) dorsal fins, large rounded pectoral flippers, curved large tail flukes and are generally larger in size than females. On average males live for about 30 years, but can reach 50-60 years.
ADULT FEMALE FACTS
Female Northern Residents have dorsal fins that are smaller and curved to the back, and are slightly smaller overall than males. On average females live for about 50 years, but can live to 100 years!
SOCIAL STRUCTURE AND BEHAVIOR
Northern Residents live in a complex matriarchal society. The calves will stay with their mother’s for their entire life span. The bonds are strong within the matrilines even after the mother has passed. Pods are formed when one or more matrilines travel together.
This group of resident whales are also known to “rub” along pebbled beaches in central and northern B.C. They have been filmed very close to shore as they swim up and rub their bodies along smooth pebbles.
STATUS
The Northern Resident Orca population is listed as threatened.
CURRENT AND HISTORICAL THREATS
The Northern Resident Killer Whale population is increasing at a rate of 4% per year. However, they are affected by low salmon runs, high toxin loads and boat disturbance.
The northern resident orcas were impacted by capture operations during the 1960s and 70s. Namu, the first orca intentionally captured for display in an aquarium, was a northern resident orca. By the time the captures were stopped, more than one third of the total resident orca population had been removed. Of these, only two survive.
- Corky is a northern resident and member of the A-23 pod. She is currently kept at Sea World San Diego.
- Lolita is a southern resident and member of L-pod who is currently kept at the Miami Seaquarium.
Orcas were also perceived as threats to fishing, and shot at or killed. During the 1950s, the Canadian Navy used the orcas as target practice.