However, these are hardly the only orca populations around the world with distinctive diets and cultures. In the North Atlantic, at least two different kinds of orcas have been observed, divided again between fish eaters and mammal eaters, while Argentina orca populations have been observed eating young leopard seals and fish alike, and in the Antarctic, at least two different kinds of killer whales have been observed devouring nearly everything that moves.
By 2011, a general consensus began to take shape in the scientific community that studied killer whales: Orcinus orca might best be understood as a “species complex,” an umbrella term for a species, disparate populations of which technically can interbreed (sperm from a male North Atlantic killer whale, as we have learned from orcas in captivity, can impregnate a Northern Resident female), but who choose not to for various reasons that are purely cultural, setting up disparate “ecotypes” with distinctive behaviors, communications, diets, and cultures.
The debate focused around a proposal by geneticist Philip Morin, who examined DNA samples from a variety of killer whale populations, that there were three new species of killer whales, along with a number of subspecies. Morin’s study found that North Pacific, North Atlantic, and Southern Ocean killer whales represented three species that were “independently evolving lineages” and deserved species status. Within those three, he suggested that other ecotypes such as mammal-eaters and fish-eaters be designated subspecies, pending further study on their evolutionary separation.
Longtime orca researcher Lance Barrett-Lennard of Vancouver suggested the “species complex” concept as a middle course, based on what he had observed about them, particularly their “social exclusivity,” which he explained “predisposes whales to form diverse, genetically isolated populations—incipient species, effectively.”
If the whales survive, he says, “we could be lucky enough to be witnessing the early stages of an adaptive radiation of killer whales whereby a variety of new species will exploit diverse ecological niches—or we could be looking at an ongoing process by which new ecotypes form and periodically wink out.
“If I’m correct and killer whales are in the relatively early stages of an adaptive radiation, the populations we see at present represent a continuum of continually diversifying forms,” and these, he says, could easily develop into a fully independent species.
So far, there are ten different ecotypes of killer whales that scientists recognize under the “species complex” approach, divided by Northern and Southern hemispheres.
Northern:
Resident Killer Whale
Almost certainly the best-studied wild cetaceans in the world—not just in the Pacific Northwest, but in Alaska as well—the more we learn about these highly social animals, the more we realize how little we actually know. All told, there are over 900 of these animals in the North Pacific, including about 80 Southern Residents from the Salish Sea, 200 Northern Residents from northern Vancouver Island, about 500 resident whales in the Gulf of Alaska, and another 100 or so elsewhere in southeastern Alaska. Highly stable social creatures, their communications are sophisticated, gregarious, and enduringly mysterious. Their fish-eating diet renders them vulnerable to overfishing of stocks by humans, and their fearless and simultaneously friendly dispositions (not to mention their relative predictability) make them a favorite of tourists and whale-watching operations. They favor pods of five to twelve members, but they also frequently gather socially with pods from within their larger community groups, sometimes even forming large “superpods.” Genetically speaking, they are also one of the most distant relatives of the whales with whom they share their waters.
Bigg’s Killer Whale
They are also known as “transient” orcas. Even though they occupy the same waters as resident whales, they have never been observed socializing with them. Rather the opposite; whenever the two happen to coincide in the same area, the reaction uniformly has been that the residents drive the Bigg’s whales away. Bigg’s whales primarily eat harbor seals (over 60 percent of their diet), but they pretty much devour everything within reach: sea lions, harbor and Dall’s porpoises, even seabirds and squid (not to mention the odd moose). Their social structure is matriarchal but is considerably more fluid than that of resident pods, and they tend toward smaller pod sizes. They also are less inclined to large social gatherings. Scientists estimate that there are about 350 of these whales in the North Pacific.
Offshore Killer Whale
The existence of these whales, who live in the open sea of the North Pacific and travel as far south as southern California and as far north as Kodiak, Alaska, was first noted by whale-watch tourists in 1988 and confirmed in 1990, but the difficulty in studying them (the waters they occupy are among some of the most notoriously rough if not outright lethal) leaves scientists with little information. They are physically smaller than both residents and transients, and their saddle patches are very faint, making them tricky to ID. Scientists have been able to identify over 200 of these whales, but many more have not been photographed. Based on documented predation, they are believed to feed primarily on deep-diving Pacific sleeper sharks. Three offshore killer whales who washed up dead along the coast of western British Columbia were found to have teeth worn down almost to the gums, something never seen in other Pacific orcas, a sign they had been feeding on sharks with their abrasive, sandpaper-like skin.
Eastern North Atlantic Killer Whale, Type 1
These whales are notably smaller than their Type 2 cousins (as well as most Pacific orcas), and scientists have puzzled over the worn teeth that typify these orcas; the speculation is that since a large portion of these killer whales’ diet is small fish like herring and mackerel, they wind up grinding their teeth more than their mammal-eating relatives. It’s also possible that, like offshores, they are dining on sharks. However, these whales have been known to eat marine mammals, also, notably harbor seals. They swim mostly in the waters around Norway where they number around 700 and Iceland where there are about 400 of them. They also appear off the northern coast of Scotland.
Eastern North Atlantic Killer Whale, Type 2
These whales mostly occupy the waters around Ireland and Scotland and number about 400. They are larger whales but feed exclusively on marine mammals, including dolphins, porpoises, and baleen whales, especially minke whales. This is a much smaller population of orcas, but they are morphologically quite distinct from Type 1 whales, being genetically closer to Antarctic whales than to their neighbors.
Southern
Antarctic Type A Killer Whale
The largest and best known of the Antarctic orcas, these animals migrate south during the summer to feed on minke whales and elephant seals along the shore of the continent. During the winter, they migrate northward to warmer climates, including some parts of the tropics. These orcas make appearances around New Zealand as well. They grow to over thirty feet in length and have distinctive saddle patches, and like other orca populations, appear to have a matriarchal social organization. It is also the largest orca population in the world, numbering around 15,000. (All told, the four Antarctic orca populations comprise over 70 percent of the world’s estimated total population of 100,000 orcas; one survey put the total Antarctic population at 80,000.)
Pack Ice Killer Whale
A slightly smaller version of the Antarctic orca with a different complexion, its skin is almost gray, with a darker section called a “dorsal cape” running from its rostrum to its fin. The white parts of its skin are slightly yellowish. These whales live around the continent, where they mostly forage for Weddell seals in loose pack ice; famously, they can be seen using formation hunting patterns to create waves that wash the seals off ice floes. They have also been observed training their young in these techniques, without actually making a kill but as practice. They also occasionally kill minke whales.
Gerlache Killer Whale
An even smaller version of the pack ice whale, it also has a grayish complexion in tw
o tones, and its white skin also often has a yellowish tint due to being infested with algae. Its eye patch is smaller than that of its larger cousins, too. These orcas occupy the Gerlache Sea and the Antarctic Peninsula, where they appear to feed mostly on penguins.
Ross Sea Killer Whale
This is the smallest of all the killer whales, with adult males reaching only about 20 feet in length. Like its Antarctic cousins, it is also slightly grayish with a cape and yellowish skin from collecting algae. Its eye patch is distinctively small, narrow, and slanted. It is believed to feed primarily on fish and can be commonly seen in the sea for which it is named, as well as in the pack ice of the eastern Antarctic.
Subantarctic (Crozet) Killer Whales
These are little-studied whales who live outside the Antarctic and primarily feed on fish in the waters between the Indian Ocean and the Antarctic. They are best known for stealing fish from the lines of fishermen who work in these waters (leading to frequent conflict and the deaths of a number of whales). However, these whales appear to be omnivorous, since they have been seen eating not just fish but also penquins, seals, fur seals, and other cetaceans.
These really are only the best known and documented populations of killer whales. The complete list of populations includes the killer whales who inhabit New Zealand’s waters much of the year, feeding primarily on rays and sharks and numbering about 300; rare, white orcas have been observed among a population of some 700 killer whales off the coast of eastern Russia’s Kamchatka region; populations off the coast of Argentina, the Caribbean Islands, the Galapagos Islands, Japan, the Strait of Gibraltar, Australia, and Tasmania; and small populations in places like Papua New Guinea, the Chagos Islands, Northwest Scotland, the Falkland Islands, and the Subantarctic Prince Edward Islands, off the coast of South Africa.
Recent genetic studies of mitochondrial DNA from all these various populations have demonstrated that the genetic relations among them vary widely. Resident and offshore killer whales in the North Pacific are relatively closely related, while transients in the same waters come from one of the earliest breaks in killer-whale lineage, some 700,000 years ago. Those North Pacific residents are from the same genetic grouping as North Atlantic whales, at least the fish eating Type 1 whales. Type 2s are from the same genetic grouping as Antarctic whales, while Bigg’s whales are off in their own universe with Ross Sea killer whales and some Eastern Tropical Pacific populations.
What the genetic map demonstrates, clearly, is that killer whales have been gradually diverging into separate populations that are so culturally distinct that they have become biologically distinct as well; if not speciation exactly, they are a dramatic living example of the process.
ORCA SOCIETIES
What is remarkable about these populations is that they also have distinctive social organizations—variations on a larger theme, to be sure, but each suited to the vicissitudes of its environments and prey types.
The larger theme is that orca societies are matriarchal. In each of the groups studied at length (and this does exclude some populations, notably the Subantarctic killer whales), orca populations are structured around their mothers. The words “pod” and “matriline” are almost interchangeable when it comes to orcas’ social structure, but there are variations on this theme.
In the classic structure from the best-known orca societies, the Northern and Southern Resident orcas of the Pacific Northwest, killer whales of both sexes remain with their mothers for life. When the mothers die and leave behind two daughters with offspring, the daughters will then often split off into their own separate pods, while remaining associated generally during larger social occasions. Regardless, the males remain with their mothers. In the event of her death, male residents will sometimes disperse to other pods with which they were socially attached previously.
Thus, in the J pod of the Southern Residents, orca watchers could enjoy for many years the spectacle of J1 and J2, Ruffles and Granny, the two best-known whales, known for leading the J pod on its arrival at Lime Kiln and other whale-watching vantage points. They were immediately identifiable; he for the massive six-foot fin that looked, on the trailing edge, like a ruffled potato chip (wavy dorsals are fairly common among Southern Resident males), she for the little half-moon nick in the middle of her dorsal. They were also renowned for their ages: When J1 finally died in 2012, it was estimated that he was sixty years old. That same year, Granny, his mother, and the matriarch of the clan, turned 100. She was still alive as of 2015.
Likewise, the K pod whale known as Cappuccino (K21) was more or less orphaned in 2012 when his mother, Raggedy (K40), died suddenly. A big male, fond of spyhopping kayakers and wowing the tourists at Lime Kiln with his big breaches, he simply picked up his bags, so to speak, and took up permanent residence with the J14 pod, a different clan altogether but a group that had been seen in company of Raggedy and her band at various times over the years.
K-21, “Cappucino,” spyhopping.
These are lifelong bonds and, indeed, appear to be essential to each killer whale’s self-identity. Home, for these whales, is not a place. Their home is each other. This profoundly affects the behavior of the killer whales, because the pod’s well-being is essential to their own. This is why, throughout killer whale societies, prey sharing is common. Cooperative behavior is the rule, and physical conflict is almost completely unknown. However, all this is only strictly true of the resident killer whales of the North Pacific, including those in southeastern Alaska and western British Columbia, which have a chief common trait of being strictly fish-eating orcas, with Chinook salmon comprising over 80 percent of their diet. Their other common trait is that they tend to socialize in larger groups of ten to twelve whales and sometimes in even larger superpods.
In other orca ecotypes, however, the details of the structures vary within the matriarchal theme. Among Bigg’s killer whales, for example, the pods tend to be much smaller and less prone to socializing. This is probably an adaptation to the requirements of hunting larger marine mammals, when stealth is required (this is also almost certainly why Bigg’s orcas are so disinclined to vocalize, at least until after they make a kill, at which time they are known to make a lot of distinctive sounds). A large group will have much more trouble sneaking up on seals and sea lions in their haul-outs, a job that can be handled more efficiently with just a few whales and a single seal can feed five, but not many more, whales.
If a Bigg’s pod grows beyond five or so whales, it will often either divide into a couple of pods, or the extraneous mature offspring, both males and females, will wander off and join other pods or travel solo. The mother remains the main organizing principal of the pods, with males playing a secondary role, evidently as hunters for the larger mammals, such as sea lions. However, it is a much more fluid social order, with pod members mixing frequently with other transient pods. Unlike the residents, Bigg’s orcas will not necessarily remain with their birth pod for life.
The best-documented case of this kind of dispersal of these whales involves some of the first mammal-eating whales encountered during the period when killer whales were being captured from Northwestern waters for display at marine parks. In 1970, six orcas, including a rare albino orca, were captured and held in a sea pen at Pedder Bay, near Victoria, the provincial capital on the southern end of Vancouver Island, British Columbia. At the time, orca captors had previously only had successful captures with fish-eating killer whales, and so they were mystified when these six whales refused to eat the fish they were given.
The albino whale, who was a female, and one of the young females, who they named Nootka, proved more amenable to the fish diet, and they were both soon moved to an aquarium display near Victoria called Sealand. The other three whales remained in the sea pen for several months: a large male with a jaw deformity who was given the name Charlie Chin and, later, the scientific designation T1, for Transient 1; his mother, designated T2; and another adult female, designated T3. T3 was the mother of the alb
ino female, who was numbered T4, and was named Chimo. Her young female companion, Nootka—probably her sister—was designated T5.
The three who remained behind refused to eat for weeks, and after 75 days, T3 died of malnutrition. Finally, four days later, T2 began to eat fish, and Charlie Chin soon followed. It wasn’t a diet they understood (no doubt it did not occur to their captors to toss a seal into their pen), but they adapted.
Things continued this way for another four and a half months, until one night someone threw a set of weights over the top of the net that held the whales in at Pedder Bay. The two survivors simply swam out of their prison that night and resumed their normal lives.
The two who remained in captivity in Sealand were not so fortunate. Chimo died two years later at the Victoria Aquarium of a lung infection; it was later ascertained that her albinism was a product of a genetic disorder that also made her more prone to illness. Nootka lived a good deal longer, surviving as a performing orca and being shuttled from one aquarium to another, with stays in Ontario, California, and Texas, before finally settling in for a stay at Sea World in San Diego, where she finally died in 1990, of a kind of pneumonia associated with ulcerated infections that turned her lungs into a mass of inflamed tissue.
The two escapees picked up where their lives had been broken. This was especially true of T2, named Florencia by her captors. She and her son, the easily identified Charlie Chin (who also had a large notch on his dorsal), were observed in Northwest waters frequently over the ensuing years, and in short order she had given birth to another male calf, designated T2a. Six years later, in 1979, she gave birth to a female calf designated T2b, at which time T2a mysteriously disappeared.
This pod continued to be one of the most commonly encountered families of Bigg’s whales throughout the 1980s in the Salish Sea, and their activities became well documented. It appeared to be an extremely stable family group. Then, in 1986, Charlie Chin started taking off from his pod and was seen swimming alone in distant reaches, sometimes as far north as the Haidi Gwaii, foraging solo. It was an unusual sight, and his striking appearance made it more so.
Of Orcas and Men Page 9