Killer Whale "John Coe": The Loneliest Killer Whale in the World
Killer Whale "John Coe": The Loneliest Killer Whale in the World
Killer Whale John Coe and his male friend Aquarius visited the Blaskets again this year on March 6th, 2018. They are part of a pod of Killer Whales known as the Scottish West Coast Community of Killer Whales, consisting of 4 males - John Coe, Floppy Fin, Comet, Aquarius - and 4 females known as Nicola (possibly mother of John Coe), Moneypenny, Puffin and Occasus. But they are a pod of Killer Whales on the edge of extinction..................
Killer Whales are fascinating animals not only because they are apex predators but because it is now evident that worldwide there are now several different orca ecotypes i.e. ecologically distinct populations or genetically distinct species which have not yet been formally described as separate species. But it is now evident that various different populations of Killer Whales are speciating - an evolutionary process by which populations evolve to become distinct species in their own right. This process may have begun over two hundred thousand years ago with Killer Whales and is still ongoing.
The trouble with the pod that John Coe belongs to is that from DNA analysis of former deceased pod members [ "LuLu" in Tiree, Scotland, 2016] it appears that the West Coast Community are an isolated community of marine mammal-eating Killer Whales, possibly originally from the Antarctic, and isolated among other populations of different fish-eating species or sub species, neither of which genetically distinct populations wish to mate or interact socially and in fact positively avoid each other.
Pods of Killer Whales are matrilineal and both male and female siblings spend their entire lives with their mother and rely on meeting other pods of genetically similar Killer Whales to socialise and mate, as killer Whales do not interbreed within their own pod. Multiple pods of Killer Whales make up a clan and multiple clans make up a genetically distinct population.
But the sad fact for John Coe and his friends Aquarius, Floppy Fin and Comet is that there are none other of their kind in the North Atlantic........
Scottish West Coast Community of Killer Whales on the Edge of Extinction
The main difference between the marine mammal-eating Killer Whales of the West Coast Community (referred to in scientific terms as North Atlantic Type 1) which prey mainly on harbour porpoises, Minke whales, dolphins and seals; and the fish-eating pods of Killer Whales further north of the Shetland islands commonly referred to as Northern Isles Community ( known scientifically as North Atlantic Type 2) who feed mainly on herring, mackerel and occasionally snack on young seal pups; are that the members of the Scottish West Coast Community of Killer Whales are bigger and about 1 meter longer on average than the Northern Isles Community; have different white colouration patches especially the back sloping eye patches and they have bigger and sharper dentition than the smaller, flattened and worn down molars of the other populations of fish-eating Killer Whales. They are also culturally different in that they do not vocalise as much as the fish-eating Killer Whales ( except perhaps after an actual kill) and are not as wildly demonstrative and acrobatic as their fish-eating counterparts.
The really astonishing fact that is now emerging from DNA analysis of the pod is that the North Atlantic Type 1 that comprise the West Coast Community of Killer Whales is most closely related to Southern Hemisphere: Type A Killer Whales which inhabit the Southern Ocean, and prey on marine mammals including Minke whales migrating to and from the Antarctic.
In all likelihood this is a pod of whales (or rather their predecessors) that sometime in the past "crossed the line" from the Southern Atlantic to the North Atlantic Ocean and have not returned and have now become isolated over time and through a combination of lack of suitable Type 1 / Type A breeding partners and also having ingested massive and toxic levels of PCBs (Polychlorinated biphenyls) in Western European waters their fertility has been adversely affected.
Until this population was found to be genetically distinct from other Killer Whale populations in the North East Atlantic Ocean, it was thought that the toxic loads of PCBs stored in the blubber of these animals [ 20 times the maximum threshold] was the reason why there has been no record of juvenile Killer Whales in this group in the almost 30 years that they have been under observation and study.
Although adult male and female Killer Whale offspring live with their mothers their entire lives, often up to 50 years, they naturally would be expected to make occasional scoping trips for potential mates..... probably the reason why we occasionally see John Coe with some of his male friends Aquarius and Floppy Fin as they journey past the Blaskets on a fruitless quest for a mate, not knowing that the nearest of his kind is far far away.............................in the Southern Ocean.
Notes on Speciation:
The great evolutionary biologist Charles Darwin was puzzled that there was not sufficient evidence of transitional forms of evolution in the fossil record (temporal) or "innumerable transitional forms" evident in existing species (spatial). Even his famous finches on the Galapagos Islands turned out to be separate species rather than just different varieties of the same species.
The Big Question is whether the different populations of Killer Whales worldwide are (1) different species (2) different sub species or (3) all forms of the same species complex?
An even greater differentiation of Killer Whale communities exist in the N.E. Pacific and the Russian Far East than in the N.E. Atlantic with two separate "resident" communities; one "transient" community and one "offshore" community. all exploiting different niches of the food chain and assiduously avoiding social and sexual contact with each other (as in the N.E. Atlantic communities) - one of the main prerequisites for genetic divergence being reproductive isolation.
Another bewildering assortment of Killer Whale communities exist in the Antarctic, including the world famous ice-floe seal-hunting Killer Whales.
The answer still perplexes evolutionary biologists and evolutionary geneticists broadly ranging ( like the Killer Whales) from the views of genetic researchers Phillip Morin et al. (2015) from genetic analysis of 450 DNA samples from Killer Whales worldwide that 3 species of Killer Whales exist with three to four sub species; to the more qualified opinion of Lance Barrett-Lennard that "Killer Whales live in a bewildering array of populations clustered within an extraordinary variety of ecotypes" and that "social exclusivity predisposes Killer Whales to form diverse, genetically isolated populations - incipient species, effectively"
Unfortunately for John Coe and company and other similar specialised small communities of Killer Whales worldwide exploiting special niches by adapting to the habitat and environment, including specialised hunting methods for exclusive prey species ranging from fish to other mammals to birds (penguins) and reptiles (turtles), if their social exclusivity cannot keep pace with the required reproductive rates to succeed as a community then advantage is with the bigger more successfully reproductive community in this "Game of Thrones" being played out in nature and John Coe may be the last of this ecotype of marine mammal-eating Killer Whales to visit our shores.
But what appears to be certain is that Killer Whales worldwide appear to be at the start ( 250,000 years is not a long time on the evolutionary clock) of what is called "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" [ Killer Whale: Evolution - Whale Watcher]
Log of whale watching tour boat M.V. "Blasket Princess" - Captain Whales Galore