Orcas of the Salish Sea
he black dorsal fin slices up slowly with barely a ripple. First it rises about a foot above the surface. Like a submarine's periscope, it travels straight ahead for twenty feet until the mighty stroke of the adult male's flukes lift six feet of dripping, wavy fin into the air. A huge torpedo-shaped head pushes out just far enough for a loud burst of air out the blowhole and a quick suck to refill the orca's lungs before it arcs silently back into the depths.
It's J3, a male over 40 years old, rising to breathe beside his family. His mother's sister plows up next to him to heave an explosive blow, followed by three more generations of J pod orcas, all closely related and inseparable their entire lives. J3's age is documented from photos taken in the first years of demographic field research in the mid-1970's. Several females are much older, however, including two, J2 and K7, both estimated to be over 90 years old.
Wispy clouds of vapor linger high over their heads as they pass a hundred yards from the lighthouse at Whale Watch Park. One of them suddenly twists in tight circles pursuing a large salmon. The others dive into the kelp, rubbing the long soft strands along their backs and into the notches of their flukes as they check for salmon hiding in the shadows. Above them the snow-whitened Olympics stand watch over this vast inland sea, glowing with red-orange hues in the early morning sun.
The orca, or killer whale, is a wondrous and impressive creature by any measure. For millions of years there has not been a predator in the sea that can touch Orcinus orca
, the largest member of the dolphin family. And yet, there is no recorded case of a free-ranging orca ever harming a human. Even when orca mothers are violently pushed away with sharp poles so their young can be wrestled into nets and loaded onto trucks, they have never attacked a human being. When seen in movies like Free Willy, or doing tricks at marine parks, it is easy to see that they often show extreme responsiveness, even affection toward humans. Having little else to do in captive situations, they often initiate playful interactions and engage in mind games with their keepers.
When encountered in their natural marine environment, however, their behavior is much different, much less interested in human affairs. Though always mindful of boats large and small, they tend to simply continue traveling, foraging or socializing with one another, as though thoroughly engaged in the complex social life of their families. Occasionally, however, some may pass surprisingly close to a boat as if to inspect the passengers as they glide with masterful ease through these vast inland waters.
The Southern Resident Orca Community
Dr. Michael Bigg, who pioneered field research on orcas in the early 1970's, designated the 70 or so orcas he found in southern BC and Washington the "Southern resident community" to distinguish them from the 120+ members (now over 250) of a different orca community found in northern BC and Alaskan waters. The three Southern resident pods, known as J, K and L pods, usually travel, forage and socialize throughout the inland waters of the Salish Sea (Puget Sound, the San Juan Islands, and Georgia Strait) from late spring through late summer seeking chinook salmon, which provide about 80% of their diet.
The Southern Resident community is an extended family, or clan, that is distinct and separate from all other orca populations. Both male and female offspring remain near their mothers throughout their lives. No other mammal known to science maintains lifetime contact between mothers and offspring of both genders. Unlike all other mammals except humans, orca females may survive up to five decades beyond their reproductive years, which begin at around 14 years of age and continue until their late 30s or early 40s.
From October through June, K and L pods tend to disappear to coastal waters over the continental shelf between northern California and SE Alaska, while J pod often reappears in the inland waters. All three pods visit lower Puget Sound during fall months in search of chum salmon. They are capable of swimming at speeds of 30 mph and usually swim from 75 to 100 miles every 24 hours. In late 2013 the Southern Residents were comprised of just 80 members.
Traveling in multi-generational pod groupings centered around females, they are believed to be led by elder matriarchs. The clan is made up of approximately 12 post-reproductive females (over 40 years old), 26 adult females (12-40 years old), 15 mature or adolescent males (over 12 years old), 10 juvenile females (under 12 years old), 15 juvenile males (under 12 years old), and 7 juveniles of unknown gender.
Each individual can be identified by its unique fin shape, markings and color patterns and can be identified by sight or photograph. Using photo-identification methods, each has been identified with a specific alphanumeric designation, such as J2 or L12, and the movements and behavior of each member and group can be studied over many decades. After each newborn has survived its first year they are also given more familiar-sounding names, such as "Luna" or "Samish." When Southern resident pods join together after a separation of a few days or a few months, they often engage in "greeting" behavior. Ritualized formations of each pod face one another for several minutes, then gradually merge into active groups, each sisting of members of different pods, accompanied by intense underwater vocalizations and spectacular "play" behavior.
Until field studies began 40 years ago, very little was known about the lifestyles or abilities of these powerful and elusive animals. As a species, orcas have the widest global range of any mammal except humans and may be seen in all types of marine ecosystems, but their highly varied communities, unpredictable movements and behaviors, and the fact that they spend about 95% of their time under water have made them difficult to study. Each orca community worldwide maintains its own repertoire of behaviors, including diet and family patterns, as well as its own vocabulary of vocalizations.
Today, thanks to the dedication of whale researchers a picture is beginning to form of the highly refined adaptations and social sophistication of this remarkable species.
When the Southern Resident orcas were first identified, one obvious mystery remained—sometimes observers found small groups of unidentified orcas separate from the large pods of known orcas. On rare occasions even solitary males were seen. Early on, it was assumed that these were outcasts, or the losers of battles for dominance. Once it was understood that there were no outcasts from the resident pods, it was determined that these small groups were actually members of a totally separate kind of orca, dubbed "transients," with radically different lifestyles. Whereas residents specialize exclusively on eating fish, especially Chinook salmon, transients hunt only marine mammals for their sustenance. Thus competition for food between the two types of orcas is virtually eliminated. Residents and transients don't mix, nor do they interbreed. Indeed, they are well on the way to becoming separate species even though they inhabit the same waters. This discovery (called sympatric speciation
), like lifetime bonding of both male and female offspring with their mothers, is unheard of in the biological sciences.
Seal populations have grown rapidly over the past forty years since passage of the Marine Mammal Protection Act in 1972, and transient orca numbers have also increased in that time. Today about 250 transients have been photo-identified, any of which may pass through the Salish Sea at any time, but are more commonly seen in the spring and fall. Transient pods are typically comprised of only two to five whales, usually found skulking silently around rocky shores near the haulouts of acoustically aware seals or sea lions. In the past ten to fifteen years much larger groups of 20 to 30 have been encountered. All transient orcas along the Pacific coast from Southeast Alaska to Mexico are believed to use similar vocalizations, indicating they are all members of a single, widespread community. At least three other transient communities have been identified across the north Pacific Ocean.
Hunting seals and sea lions requires stealth and silence to stalk the wary marine mammals, so group size must not exceed four or five whales. First-born transient males and females usually stay with their mothers for life, whereas younger brothers and sisters tend to break off from their mothers and either travel with other transients or remain solitary. In at least one case, a female returned to her mother after giving birth to a calf of her own, indicating the family's emotional bonds had not been broken even though mother and daughter were separated by more than a thousand miles for several years.
In the early 1980's, Dr. John Ford formulated the results of ten years of listening in on orca conversations. Ford discovered that each orca community has its own distinct set of characteristic calls. The transients and residents, for instance, speak different "languages." It is believed that every orca community around the oceanic globe uses its own, completely unique, set of calls. Orcas are highly communicative, and the ability to distinguish themselves using the calls of their particular family group is essential to their survival. When maintained in marine parks they retain their native calls for life, even while they learn new calls from fellow captives caught from other communities. To hear Southern Resident orcas as they forage, echolocate, and vocalize, go to the Salish Sea hydrophone network
Orcas of the Salish Sea, Part II