SRKW
The Southern Resident Killer Whales (SRKW) are a group of orcas comprised of three pods or family groups: J,K, and L pods. As November 2018, there are 74 individuals – J pod currently has 21 members, K pod has 18, and L pod has 35.
When all three pods unite, usually in the beginning of the summer after returning from a winter in search for food, members from each pod will interact with one another and this is called a super pod. Killer whale’s movement patterns are dependent on the movement patterns of their food source. Unlike transient orcas, the marine-mammal diet orcas, SRKW feed primarily on Chinook salmon. Orcas have been an important part of the tribal culture of thousands of years and are an iconic megafauna of the Pacific Northwest.
Range
The Southern Residents usually spend the summer months in and around Washington State and southwest British Columbia. In the winter, the orca’s main food source, Chinook salmon become less abundant and the whales travel and expand their range in search of food. L and K pods are known to travel to the northern coast of California in the winter months and J pod normally stays closer to the Salish Sea. The SRKW will travel as far south as Monterey Bay, California and north towards Haida Gwaii but have also been seen as far north as Alaska.
There are three kinds of orcas that live in the Pacific Northwest, differentiated by diet, social structure and range. The other two orcas are transients, who eat marine mammals, travel in smaller family groups, and have a wider ranger with a less predictable travel patterns. The third group is the offshores who live in the open ocean and eat sharks. They are the least likely kind of orca to be found in the Salish Sea. These groups are genetically distinct and are not believe to interbreed.
Biology
Killer whales are in the family Delphinidae and are the largest species of dolphin. They are also the most widely distributed marine mammal world wide. The Southern Residents got their name from inhabiting the waters off the southern end of Vancouver Island and the inland waters of Washington, in comparison to the Northern Resident Killer Whales who are most likely encountered in the waters off the northern end of Vancouver Island and range to Haida Gwaii and Southeast Alaska.
SRKW can travel as fast as 30 miles per hour (48 km) and are able to sustain an average speed of just over 6 knots (8 mph/12.8 km per hour). They travel an average of 75 miles (120 kilometers) in a single day, and that travel is usually, if not always, with their pods and matriarch lineages. Each orca can be identified by their individual markings, called saddle patches, which is located behind the dorsal fin. Orcas have the second largest brain at around 17 pounds, second to the sperm whale
- The Whale Trail